Friday 2010-12-10 Dev. video update and Discussion

[Oleg Maddox]

Hi,

I promised to post videos some time.
Here is the first of them.

1. Engine start. Flame and smoke effect. Every start is different (in realtion to emulation of real engine cylinders work by a program).
Sound is currently a place holder. Unfortunately I wasn't able to record in a track at the moment maximal settings (some unpredictable bug in recording of video need to be found and eliminated )

http://www.youtube.com/watch?v=G836qqOhhZ8

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions

http://www.youtube.com/watch?v=KTx5v8jeFdw

[leggit]

awesome...maybe a little red or orange would be good.

[Wutz]

Well this is not a british engine but maybe this gives you an idea how it should look like?
http://www.youtube.com/watch?v=4ZzvKCQwWj0

[F19_lacrits]

Very nice update! Videos are always so much more than still pictures.. :D
Yeah, maybe a little too yellow.. should it not be more white rather than redish?
[EDIT] ok.. after seing Wutz vid of the DB.. (I wasn't way off with "more white") I change my mind to whitish-blue ;)

[JG52Krupi]

Sweet, thanks Oleg.

Yes a bit too yellow, needs to be turned down and perhaps blue after effects added like in the video Wutz linked too...

[Aer9o]

Hi,

I promised to post videos some time.
Here is the first of them.

1. Engine start. Flame and smoke effect. Every start is different (in realtion to emulation of real engine cylinders work by a program).
Sound is currently a place holder. Unfortunately I wasn't able to record in a track at the moment maximal settings (some unpredictable bug in recording of video need to be found and eliminated )

http://www.youtube.com/watch?v=G836qqOhhZ8

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions

http://www.youtube.com/watch?v=KTx5v8jeFdw

Way too small detail to worry about...release the game as it is :-P!

[JG27CaptStubing]

I would go more with Blue...

[KOM.Nausicaa]

Hello Oleg --

many thanks for the update !

Yes, I think it's too yellow. It should actualle be more white/blueish, like in the DB 605 engine video posted above. But I have to admit that I have no idea what the difference from engine type to engine type makes.

[ATAG_Dutch]

Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions


In all of the accounts I've read, the pilots refer to Blue flames from the exhausts at night.

The flames matching the firing order is very impressive!:grin:

[RedToo]

Excellent work. Probably less yellow.

RedToo.

[Oleg Maddox]

Well this is not a british engine but maybe this gives you an idea how it should look like?
http://www.youtube.com/watch?v=4ZzvKCQwWj0

No, this doesn't give me idea... Load the sound file from this video in a professional sound edit program and look for the spectrum... You will see there soo poor range and will be very impressed if you will load the same from a track above (our), even it is a place holder yet...

However I see the color of exhaust here in DB. Interesting with which gazoline and settings for start :) Becasue exaust color depending of many-many "settings".

[Trumper]

:) WOW ,Thanks Oleg.Tunable colours and pistons firing imprecisely according to differing conditions that sounds good.
Will the engine be able to be made to misfire due to poor management inflight or due to damage?
LOL :) I wonder if the groundcrew can be singed and made sooty by backfiring engines :)

[Wutz]

No, this doesn't give me idea... Load the sound file from this video in a professional sound edit program and look for the spectrum... You will see there soo poor range and will be very impressed if you will load the same from a track above (our), even it is a place holder yet...

However I see the color of exhaust here in DB. Interesting with which gazoline and settings for start :) Becasue exaust color depending of many-many "settings".
Sorry Oleg I did not mean the sound, but the exhaust flames coming out. Sorry if I did not state that clear enough.

[Oleg Maddox]

I would go more with Blue...

It is depending of gazoline, pressure, RPM, and so many other factors... Even at different altitudes it is different really...

We have original table of the exhaust colors by which British crew were need to define is in good or not so good conditions the engine before the flight...

[JVM]

Hello Oleg!

If there is a program managing each exhaust pipe individually, could it be possible to expand it in order to make the exhaust flames yellow + puffs of black smoke + irregular firing tending quickly toward blue + no smoke (or slight stream of translucid grey), as Wutz video shows?
Exhaust flames at high RPM were indeed blue (assuming the pilots were managing mixture, which was generally the case!)

JVM

[BadAim]

Don't forget the cooling effect of the exhaust stacks on the spit. I don't have a video to hand but you would have much cooler unburned fuel flames with this type of exhaust than with the straight stacks on the Daimler engine. I'm actually of a mind with Oleg, that the flame needs to be "cooled down" a little.

[Richie]

Blueish. Daimlers burn very rich though and burn low grade fuel, 87% octane. Would they still burn that now? They had much lower compression ratios than merlins but they were made that way because the Germans didn't have access to the good fuels that the allies had. Lower compression engines run well...better one low grade fuels than they do on high grade fuels. It's probably why they had such a bigger displacement than Merlins 27 I think and 34 liters. Bigger displacement to get the power.

[Oleg Maddox]

I need immediatly to run from office.

Please if you find any materials that to show, read, and you own suggestion - write it here.
I and my guys will read it.

I will be back soon. Hope on Sunday.

[Sutts]

Very impressive effects Oleg, thanks:grin:. I love the fact that you worry about little details like this. Will the engine require more turns of the prop sometimes before starting? Will we sometimes have to try twice to start it like in the DB video?

Thanks for taking the time to update us. It is appreciated.

[KOM.Nausicaa]

It is depending of gazoline, pressure, RPM, and so many other factors... Even at different altitudes it is different really...

We have original table of the exhaust colors by which British crew were need to define is in good or not so good conditions the engine before the flight...


Ok, but even if it's dependent on those factors, and there would be set of factors that would produce yellow colors like in the video you posted, it's still too yellow. Actually, the problem is (as far as I can see in compressed video) that the spectrum is too narrow. There should be a wider range of subtle hue/value (not saturation) difference in the different flames as they appear, in some random pattern.
It's however hard to tell -- who knows what the video codec does, and then it's that everyone has a different monitor. I played it however on my color calibrated Wacom Cintiq, and that is what I thought first.

[Old_Canuck]

Agree that most accounts I've read also mention intercepting at night by spotting blue flames.

[smink1701]

Looks like my thread did the trick:rolleyes:

Thanks Oleg

[Flanker35M]

S!

Thank you for the update :) Nice to see things shaping up. In that DB605 video you can see the root of the flame has reddish/yellow but the tip of it is blueish. Could the British and German difference be that Brits and other allies had carburettors and Germans had direct fuel injection in their DB/Jumo/BMW engines. The mixture in a fuel injected engine, like DB-series, is better than in a carburettor engine and high pressure spray of fuel gives more even fill of the cylinder at the right time compared to the suction in a carburettor system.

Also many nightfighter books I have read state blueish flames on British bombers. And there was a talk witha guy who tuned/maintained DB engines and he said the engine tunes were done in a dark room to see the exhaust flame color to adjust the injection etc. correctly.

Ok, have a good weekend all! :)

[Jg2001_Rasputin]

Merlin V12 Startup, I see a lot of blue

http://www.youtube.com/watch?v=AqrbtxcNqbM&feature=related

[Towarisch]

GREAT , GREAT , Pictures and this in motion. :grin:

Thank you so much for this great Friday update. With every Friday evenning beats our hearts a little bit more for this great Game:-)

I think we all wish you, your famaly and your team too.. a nice peacefull christmastime and a happy new year 2011.

Thank you Mr. Oleg


with regards from Old Germany

[Wutz]

Here is a Merlin engine being started, but one see no flames at all, maybe only visable during night time?
http://www.youtube.com/watch?v=yprfH5ZsAHk&feature=related

[Richie]

No, this doesn't give me idea... Load the sound file from this video in a professional sound edit program and look for the spectrum... You will see there soo poor range and will be very impressed if you will load the same from a track above (our), even it is a place holder yet...

However I see the color of exhaust here in DB. Interesting with which gazoline and settings for start :) Becasue exaust color depending of many-many "settings".



Oleg.....Spitfire flames in the dark and they are blue!!


http://www.youtube.com/watch?v=QhFAwSk9Vqg

[Trumper]

:) Do these help
http://www.youtube.com/watch?v=AqrbtxcNqbM

http://www.youtube.com/watch?v=3arJP5cLRdM&feature=related 7 mins in

http://www.youtube.com/watch?v=k9AGbrGBjQQ&feature=related 3 mins in for night time CREDIT TO THE AUTHORS OF THE VIDEOS

[BadAim]

S!

Thank you for the update :) Nice to see things shaping up. In that DB605 video you can see the root of the flame has reddish/yellow but the tip of it is blueish. Could the British and German difference be that Brits and other allies had carburettors and Germans had direct fuel injection in their DB/Jumo/BMW engines. The mixture in a fuel injected engine, like DB-series, is better than in a carburettor engine and high pressure spray of fuel gives more even fill of the cylinder at the right time compared to the suction in a carburettor system.

Also many nightfighter books I have read state blueish flames on British bombers. And there was a talk witha guy who tuned/maintained DB engines and he said the engine tunes were done in a dark room to see the exhaust flame color to adjust the injection etc. correctly.

Ok, have a good weekend all! :)

Don't forget that in the Daimler video, (as far as it seems to me) they were starting the engine for the first time, so they went straight into a "break in run" at a much higher than Idle RPM. (it's been a long time since I've built an engine, but I think I'd typically "run in" a chevy big block at about 2000 RPM for about 15 minutes) That kind of RPM will of course produce a hotter flame than a typical start to idle of an already broken in engine. This will also (as Oleg pointed out ) explain the difference between the flame seen at start up and in flight.

[BadAim]

Big LOLs. Oleg sure has his work cut out for him. I'd not be surprised if this thread doesn't cure him from appeals to us for help!

[Solnyshko]

Re exhaust stacks; my understanding is that it was the cooling pipes that glowed red, and it was this 'hot metal' and not the flame which was visible from a distance - especially relevant in night fighting.

[JAMF]

Mr. Maddox, a quick question on last weeks update; Was the map in the FMB a temporary version, or does the SoW map have structures from after the war? (Like the Basin de L'Atlantique at Gravelines, WSW of Dunkerque?)

[Old_Canuck]

Bear in mind that the Luftwaffe used effective flame dampeners. After extensive training in identifying flame patterns an American pilot said he never saw flames due to the dampeners but the training did help him separate Luftwaffe flights from Allied.

[Flanker35M]

S!

I doubt they would run up the DB engine above idle as the manual for it states you have to wait until oil/fuel pressure exceed a certain limit. The idle RPM for DB605A-1 is 600-700rpm and in the video the RPM was not high IMO. But good points BadAim. Anyway in above videos can be clearly seen blue flames instead of yellow. I would bet the yellow would come if the mixture was way too rich or unburned fuel in the cylinders when firing up. Well, let's see..Also note that the blue flame did not light up the plane as much as in SoW video.

[Oleg Maddox]

Merlin V12 Startup, I see a lot of blue

http://www.youtube.com/watch?v=AqrbtxcNqbM&feature=related

Please read with atention: The color of exhaust from the direct pipe and from the extended are different. The temperatue of the flame decreasing with the longer leght of pipe. More lower temperature - more red flame. The most hight is right from the hole without pipe.

As I told above a lot of factors is present in forming of color.

[speculum jockey]

Hello Oleg --

many thanks for the update !

Yes, I think it's too yellow. It should actualle be more white/blueish, like in the DB 605 engine video posted above. But I have to admit that I have no idea what the difference from engine type to engine type makes.

They're all pretty much the same. Big row of cylinders igniting avgas in them and venting the exhaust out the pipes in the side. Unless there was some sort of addidive that would change the colour (not likely) then they'd all be blue like you're suggesting.

The flashes are one reason why some 109's had the exhaust shield covering the pipes, so they would not be seen in low-light conditions, but as oleg just mentioned there are other factors at work.

[swiss]

.

[Flanker35M]

S!

If comparing Spitfire Mk.I/Hurricane early marks and Bf109E-4 it can be easily seen that the Spitfire/Hurricane have longer exhaust pipes than Messerschmitt. I recall reading the exhausts on a DB engine were very short, in range of 10-15cm only.

[KOM.Nausicaa]

They're all pretty much the same. Big row of cylinders igniting avgas in them and venting the exhaust out the pipes in the side. Unless there was some sort of addidive that would change the colour (not likely) then they'd all be blue like you're suggesting.

The flashes are one reason why some 109's had the exhaust shield covering the pipes, so they would not be seen in low-light conditions, but as oleg just mentioned there are other factors at work.

I already corrected myself after Oleg's post.

[Oleg Maddox]

Mr. Maddox, a quick question on last weeks update; Was the map in the FMB a temporary version, or does the SoW map have structures from after the war? (Like the Basin de L'Atlantique at Gravelines, WSW of Dunkerque?)

Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc. We was need to cut by this way. Originally plannen way more greater. But there is a great contradicitons between what to put in terms of detailization and what would be the size due to this detalization. Again it is impossible to make everything withouit going for compromisses.
In Il-2 in every map we had also compromisses. Repeat: in every, is it crimea or moscow map, etc. And we were need to cut other possible historical action as well due to this fact .

[T}{OR]

Lovely update. Love the individual cylinder firing. Shame early Spits have cylinder exhausts in pairs, I love to see them firing in proper firing order accompanied with the exhaust flames, faster and faster as RPM grow. Out of all all in-line engines, nothing beats the magnificent, almost perfectly balanced V12. :)

As for the flames, I too would like to see them more 'on the blue side'. However, as you have said it all depends on the fuel quality, which is nowhere near when compared with what we have nowadays. Definitely a mix of yellow/orange and blue burnout...

[speculum jockey]

I just learned the Spit only had ammo for roughly 16 seconds of continuous firing - will they be modeled like that?

source:
http://www.quarry.nildram.co.uk/BoB.htm

It was already in IL2, so should be the same in SOW.

Try taking a late war 109 for a spin and see how fast it runs out of the good stuff (30mm hub cannon). The only planes that seem to have "Hollywood" levels of ammo are the larger American fighters like the Corsair, and P-47. If you opt for the P-47 with extra ammo you can hold down the trigger the entire length of your mission and still land with enough lead in the guns to down a bomber.

I imagine that Oleg and Co. have figured out the exact historical loadout for all the fighters involved and you won't be given an extra round.

[I/ZG52_Gaga]

Just by dealing with exhaustion effect - during night - time, means only 1 thing ...

the new title has gone onto another level all together and that is apreciated by all

IL2 fanatic customers.

[zapatista]

Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc. We was need to cut by this way. Originally plannen way more greater. But there is a great contradicitons between what to put in terms of detailization and what would be the size due to this detalization. Again it is impossible to make everything withouit going for compromisses.
In Il-2 in every map we had also compromisses. Repeat: in every, is it crimea or moscow map, etc. And we were need to cut other possible historical action as well due to this fact .

Oleg,

but if currently cities and towns on the BoB map are moddeled to large (compared to 1940's maps), are we not wasting fpsec on having our pc's draw and display houses/buildings which are not needed ?

see the end of last weeks thread for discussion on this, and historical maps of town sizes posted (in comparison to what was seen on the recent BoB preview maps)

note: this is intended as constructive input, not a "complaint"

[Flanker35M]

S!

Quickly read some things and found this explaining the flame color quite simply and well: "The flame colour of stoichiometric burning is described as a "bunsen blue", turning to yellow if the mixture is rich and whitish-blue if too lean." I hope this helps.

[addman]

Just by dealing with exhaustion effect - during night - time, means only 1 thing ...

the new title has gone onto another level all together and that is apreciated by all

IL2 fanatic customers.

I think that's a qualified assessment and I'm inclined to agree.

[AWL_Spinner]

Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc.


Hi Oleg, JAMF's question was I believe purely relating to geographical features visible on the mini-map that were not in existence in 1940 (or, indeed, until after the war).

In other words: content accuracy, not map size (also regarding the extent of some cities and towns in 1940).

Great video update, thankyou!

Incidentally I'm also in the "blue" flame camp. I acknowledge the aircraft I see at Duxford are using top-quality fuel that may not have been around in 1940, but I do recall pilot accounts in various books I've read describing blue flames from Merlin engines at night.

Cheers!

Spinner

[PeterPanPan]

Very nice Oleg. I know it's not to do with engine start, but looking at the first video, I wonder of the red gun port tape will change once the guns are fired? Small detail, but was just wondering.

PPanPan

[C_G]

Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc. We was need to cut by this way. Originally plannen way more greater. But there is a great contradicitons between what to put in terms of detailization and what would be the size due to this detalization. Again it is impossible to make everything withouit going for compromisses.
In Il-2 in every map we had also compromisses. Repeat: in every, is it crimea or moscow map, etc. And we were need to cut other possible historical action as well due to this fact .

Oleg,

JAMF is not referring to the size of the map (and, for example, no Duxford).

He is writing about some cities being larger than they were in 1940 and the map including POST-1940 structures. Dunkirk's Bassin de l'Atlantique, which is on the SoW:BoB map but wasn't built until after the war, for example.

C_G

[kestrel79]

I think the flames look great, going by those videos posted and seeing other engines at night in person I would have to agree more blue and red flames...but again I trust Oleg and his research on the different fuels and factors that I have no idea about.

My main concern is the flame reflections. In all the real videos posted you don't see any reflections of the flames on the aircraft. Where in the night video posted by Oleg it almost looks like a police car light reflecting off the aircraft.

Make the flames more red and blue, reduce reflections and I think we have a winner. Great update thanks! :grin:

Flying at night is going to be awesome in BoB!

[BigPickle]

Definitely less yellow or red, the fire should be a blue colour Oleg. This is caused because the exhaust outlets are for the gases made when the fuel is burn and that gas burns blue.
I loved the way when the spitfire started, it wasn't just one burst of flame. I love the modelling system you have for engine starts. Well done Oleg and team!

[Richie]

Rich mixes, air to fuel, helps older engines with lubrication also but you'd have to clean out ports and valves more often because of the excess carbon

[David603]

Very nice Oleg. I know it's not to do with engine start, but looking at the first video, I wonder of the red gun port tape will change once the guns are fired? Small detail, but was just wondering.

PPanPan
Yes, the tape tears when the guns are fired.

[KG26_Alpha]

Hi Oleg

You have the flame colour about right for initial start up but probably to fast in engine speed, slower start to run up.

I've seen a few of these engines start up :)

1. Lazy/slow red/yellow flame from fuel primed start up.

2. Blue smoke clearing cylinders with yellow flames to brown/grey smoke.

3. Blue with yellow tips on engine run up and under run.

4. Shut down black/grey exhaust smoke short burst.

If I can find some of my video will e-mail it.

[Mardescrap]

What I like each time an update is posted is the army of volunteer Art directors and armchair historians/aviators that come in adding their salt to the soup.

This time it's exhaust flame color. Last time it was about map size. I'd be curious to see how many folks asking for changes or complaining ever worked on a game. How many of those folks are ready to upgrade their rigs to get a decent FPS.

Seriously there is a diffrence between asking questions and demanding changes on an unfinished product. It's already good that those little things are in there. It could just be a non lighted reddish texture mapped in the exhaust and have it called an exhaust glow but there are lights actually lighting up the engine cowling and particles, that's good.

Anyway keep up the good work, thanks for the updates, they make my day.

BTW are you alpha or you're beta?

[swiss]

It was already in IL2, so should be the same in SOW.

Try taking a late war 109 for a spin and see how fast it runs out of the good stuff (30mm hub cannon). The only planes that seem to have "Hollywood" levels of ammo are the larger American fighters like the Corsair, and P-47. If you opt for the P-47 with extra ammo you can hold down the trigger the entire length of your mission and still land with enough lead in the guns to down a bomber.

I imagine that Oleg and Co. have figured out the exact historical loadout for all the fighters involved and you won't be given an extra round.


I just clocked it(UP2.01 MkI).

1st: You're right
2nd: I am an Idiot, should have done that before.
3rd: deleted my post - to save space and the original is quoted anyway.

Sorry.

[JG53Harti]

Duxford 2009 (the size of the pictures is reduced)

[Fafnir_6]

Awesome videos! Thanks for posting. I really like the way the propellor has been animated in BoB (it shows how the human eye would see it in real life - for added immersion :)). My question (more of a suggestion, really) is for those of us who wish to create screenshots with a period feel (where the prop blades are visible as dark bands around the propellor hub due to shutter speeds/refresh rates??). Would it be possible, perhaps in a future update of BoB to have propellor effects toggleable so that the default would be the realistic effect you have now in game but that an IL-2-style propellor effect could be selectable for the purposes of period screenshooting?

Just a thought,

Fafnir_6

[C_G]

What I like each time an update is posted is the army of volunteer Art directors and armchair historians/aviators that come in adding their salt to the soup.

This time it's exhaust flame color. Last time it was about map size. I'd be curious to see how many folks asking for changes or complaining ever worked on a game. How many of those folks are ready to upgrade their rigs to get a decent FPS.

Seriously there is a diffrence between asking questions and demanding changes on an unfinished product. It's already good that those little things are in there. It could just be a non lighted reddish texture mapped in the exhaust and have it called an exhaust glow but there are lights actually lighting up the engine cowling and particles, that's good.

Anyway keep up the good work, thanks for the updates, they make my day.

BTW are you alpha or you're beta?

DUDE, Oleg specifically asked for input on the exhaust flames!

No-one has been whining that they're not good enough. The posts on flame colour have all been constructive and backed-up their opinions with something.

Clearly this is something that Oleg is still tweaking.

He's made it clear that the map SIZE is set and not open to debate, but I don't see anyone whining about that. Some of us would like to know, however, if the map objects are still open to revision. Also not whining just a query.

C_G

[KG26_Alpha]

What I like each time an update is posted is the army of volunteer Art directors and armchair historians/aviators that come in adding their salt to the soup.

This time it's exhaust flame color. Last time it was about map size. I'd be curious to see how many folks asking for changes or complaining ever worked on a game. How many of those folks are ready to upgrade their rigs to get a decent FPS.

Seriously there is a diffrence between asking questions and demanding changes on an unfinished product.


Hi

Please read Olegs first post in this Friday update.

He's asking for advice from those that have seen these things in real life.


Woops well done C G you beat me to it :)

[KOM.Nausicaa]

What I like each time an update is posted is the army of volunteer Art directors

hehe..actually I am an art director ;-) but never mind, it's not about that.

[ElAurens]

Duxford 2009 (the size of the pictures is reduced)

That amount of flame from the stacks at start up points to one thing, and one thing only, the engine was grossly over primed before start up.

I have seen dozens upon dozens of Merlins, Allisons, Wasps, Cyclones, and a DB 601 start, all in day time, and never once have seen that much flame come out of the stacks. Smoke certainly, and lots of it on some engines, but never large curling flames like that. Operator error, pure and simple.

[ChrisDNT]

Not bad, but the flames are still too "yellowish" like in IL-2.

[Qpassa]

its sad to hear a spitfire with sounds of BF109 in IL2-1946

[JG52Krupi]

its sad to hear a spitfire with sounds of BF109 in IL2-1946

Its sad to hear some one say there is a DB601/5 engine sound in il2 :lol:

[Richie]

You've got to know that those sounds are no way the final sounds LOL

[Art-J]

Here's a nice night vid with blue flames. Don't know the details of mixture setting, but for such a high RPM run-up we might suppose it was rather on the rich side. On the other hand, no short stacks here, so direct comparison is not possible...

http://www.youtube.com/watch?v=wMPdV6xA8X0

Cheers

[Baron]

DUDE, Oleg specifically asked for input on the exhaust flames!

No-one has been whining that they're not good enough. The posts on flame colour have all been constructive and backed-up their opinions with something.

Clearly this is something that Oleg is still tweaking.

He's made it clear that the map SIZE is set and not open to debate, but I don't see anyone whining about that. Some of us would like to know, however, if the map objects are still open to revision. Also not whining just a query.

C_G


He also explained why blue exaust in most instances is incorrect yet most here want it to be blue?

Maby the refferance in books saying the colour is blue is because they saw the flames in an angle looking straight down the stacks so to speak (from an angle and from behind) , like oleg explained, flames are blue just at the beginning of the outlet and gets more yellow the longer the stacks are.

just guessing.

[JVM]

Here's a nice night vid with blue flames. Don't know the details of mixture setting, but for such a high RPM run-up we might suppose it was rather on the rich side. On the other hand, no short stacks here, so direct comparison is not possible...


Cheers

Very interesting video! It is interesting to see how at high RPM the flames are definitely blue, even with long pipes, but when each flame appears could it be that for this short time the exhaust pipe itself goes cherry-red/yellow? This would maybe explain what one sees...

JV

[Katkatman]

One question about the last topic :
Will the ground vehicule could be weathered like the planes (maybe in a futur part) or not ?

Great work also :-)

[AdMan]

the light radiating from the flame is too yellow no matter what the color of the flame, too much saturation

[winny]

Flame colour has nothing to do with the angle you view it from or the length of the exhaust pipe, it is nothing to do with temperature either. It simply shows how efficiently the fuel is burning.

If the combustion is burning all the carbon you get blue flames and no smoke. If there's carbon coming out in the exhaust gases then you'll get yellow-er/smoky-er flame.

This is chemistry not opinion.

[Richie]

Hawker Sea Furry?

[McHilt]

Seeing all the vids of merlins and DBs I'd say blueish like many before me.
The color of flames indicate temperature and as temperature increases flames turn more transparent (the hottest temperatures are nearly invisible as I remember from chemistry class) but hey, I'm not an expert at that
I think the flames should be more transparent (in case when you'd use blueish flames). They also should illuminate the fuselage just slightly... just my opinion as a draughtsman, from what I've seen in the vids posted.

Anyway, nice feature...

Edit: maybe winny is right about that, efficiency rather than temperature but still

[changai]

It is depending of gazoline, pressure, RPM, and so many other factors... Even at different altitudes it is different really...Actually, Winny is right, it doesn't depend on those factors.
Color is related to the temperature of gases produced during combustion: the hotter, the whiter; the colder, the redder. Blue indicates a very high temperature. Near-perfect combustion of hydrocarbons is always blue.

Yellow indicates an imperfect combustion, i.e. lack of combustive agent (usually air) which causes production of soot, i.e. smoke. However, even a very rich mixture as used on a cold engine would not produce yellow flames, but add a yellowish hue at the end of blue flames.

Red indicates a very bad combustion. A damaged engine burning oil would probably produce reddish flames.

Hope this helps ;)

[Redwan]

Fantastic job !!!

[ATAG_Dutch]

Is anyone familiar with the colour produced when the 'Ki gas' primer is used with full rich mixture, 100 octane fuel and a cold engine?

These are the only factors I can think of which might together produce a yellow flame, other than unburnt fuel igniting against hot exhaust stubs, which from video evidence already posted is more orange.

Otherwise, I'm a little confused as to why our opinions were invited. All evidences posted point to blue flames and yet we're told we're wrong.


'Confused' of Milton Keynes

[Flanker]

The sound of the plane is the same as in il-2. Is it just temporary or final?

[winny]

Seeing all the vids of merlins and DBs I'd say blueish like many before me.
The color of flames indicate temperature and as temperature increases flames turn more transparent (the hottest temperatures are nearly invisible as I remember from chemistry class) but hey, I'm not an expert at that
I think the flames should be more transparent (in case when you'd use blueish flames). They also should illuminate the fuselage just slightly... just my opinion as a draughtsman, from what I've seen in the vids posted.

Anyway, nice feature...

Edit: maybe winny is right about that, efficiency rather than temperature but still

I'm probably being a little pedantic, sorry :)

Temperature is related to efficiency of burning too, so it is linked to the flame colour, but as they are both effects and have the same cause I ignored it..

You could get yellower flames from an exhaust pipe that had a build up of soot inside or around the edges of the pipe, but this would eventually burn away.. maybe they start yellower because the pipes are dirty?

I know that when they were testing the Spitfire at Boscombe Downs for night flights it was recorded that the exhaust flames were blue.

[AdMan]

Is anyone familiar with the colour produced when the 'Ki gas' primer is used with full rich mixture, 100 octane fuel and a cold engine?

These are the only factors I can think of which might together produce a yellow flame, other than unburnt fuel igniting against hot exhaust stubs, which from video evidence already posted is more orange.

Otherwise, I'm a little confused as to why our opinions were invited. All evidences posted point to blue flames and yet we're told we're wrong.


'Confused' of Milton Keynes
I was going to say something to this effect in harsher words but decided against it

[AdMan]

Flame colour has nothing to do with the angle you view it from or the length of the exhaust pipe, it is nothing to do with temperature either. It simply shows how efficiently the fuel is burning.

If the combustion is burning all the carbon you get blue flames and no smoke. If there's carbon coming out in the exhaust gases then you'll get yellow-er/smoky-er flame.

This is chemistry not opinion.

Actually, Winny is right, it doesn't depend on those factors.
Color is related to the temperature of gases produced during combustion: the hotter, the whiter; the colder, the redder. Blue indicates a very high temperature. Near-perfect combustion of hydrocarbons is always blue.

Yellow indicates an imperfect combustion, i.e. lack of combustive agent (usually air) which causes production of soot, i.e. smoke. However, even a very rich mixture as used on a cold engine would not produce yellow flames, but add a yellowish hue at the end of blue flames.

Red indicates a very bad combustion. A damaged engine burning oil would probably produce reddish flames.

Hope this helps ;)

these people seem to make sense

[Rodolphe]

Actually, Winny is right, it doesn't depend on those factors.
Color is related to the temperature of gases produced during combustion: the hotter, the whiter; the colder, the redder. Blue indicates a very high temperature. Near-perfect combustion of hydrocarbons is always blue.

Yellow indicates an imperfect combustion, i.e. lack of combustive agent (usually air) which causes production of soot, i.e. smoke. However, even a very rich mixture as used on a cold engine would not produce yellow flames, but add a yellowish hue at the end of blue flames.

Red indicates a very bad combustion. A damaged engine burning oil would probably produce reddish flames.

Hope this helps ;)



Welcome Changai.

Thanks for your first post here, and I can say that you are Spot On !

Following the A.P. 1565 A (Spitfire I, Merlin II or III engine) 'STARTING THE ENGINE AND WARMING' procedure, the mixture should be in Full Rich with a 1/2 inch open Throttle , not quite a blue near-perfect combustion situation. ;)

On this 'September Fury' dusk video, the blue flames panache appears only at a continuous high power regime.
Note the absence of blue light reflection on the 'Fury' fuselage.


and by the way, thanks for the Update. ; )


...

[ATAG_Dutch]

these people seem to make sense

Yes, it's the 'Ki gas' primer I don't know about.:)

[Blackdog_kt]

Please read with atention: The color of exhaust from the direct pipe and from the extended are different. The temperatue of the flame decreasing with the longer leght of pipe. More lower temperature - more red flame. The most hight is right from the hole without pipe.

As I told above a lot of factors is present in forming of color.

Exactly. In general, hot=blue, cool=red/yellow, plus a flame that's seen directly exiting the piston will be hotter than a flame seen after travelling the entire length of the exhaust pipe.

So, since the colour is a function of exhaust gas temperature, i guess that running on higher power will produce bluer flames. Also, leaning the mixture at night could be done by watching the flames, you just have to lean until the highest exhaust gas temp which means the bluest flame you can get, then enrich it again just a tad from that point.

I might know how the stuff generally works but it don't know what the correct colour for each circumstance is. However, i'm really excited about these features because they give the impression of a real, working machine under the hood. Excellent update!

:grin:


Flame colour has nothing to do with the angle you view it from or the length of the exhaust pipe, it is nothing to do with temperature either. It simply shows how efficiently the fuel is burning.

If the combustion is burning all the carbon you get blue flames and no smoke. If there's carbon coming out in the exhaust gases then you'll get yellow-er/smoky-er flame.

This is chemistry not opinion.

...and the way pilots of prop driven aircraft adjust their mixture today is by, guess what, a temperature gauge that monitors how hot the exhaust gas is. So you're correct generally, except the part where you say it has nothing to do with temperature. This is also not opinion but physics, whatever burns hotter is to the blue/white side of the spectrum and stuff that burns cooler is to the red/yellow side. It's the reason even the stars are not all the same colour. Cheers ;)


Edit: I just saw you corrected it yourself :grin:

[winny]

So, now I've thought about it.. anytime the engine is running efficiently we should see blue-er flames in SoW.

The less efficiently the engine runs the yellow-er the flame.

That would beg the question, what effects an Aero engines effectivness at burning fuel?

Rubbish fuel?
Altitude?
Damage?
Mixture?

I put question marks because when it comes to engines I find them exactly like women.. I love them, but I dont understand how they work...

[Sutts]

:) Do these help
http://www.youtube.com/watch?v=AqrbtxcNqbM

http://www.youtube.com/watch?v=3arJP5cLRdM&feature=related 7 mins in

http://www.youtube.com/watch?v=k9AGbrGBjQQ&feature=related 3 mins in for night time CREDIT TO THE AUTHORS OF THE VIDEOS


Great videos Trumper. I've put together a few stills from the Just Jane night runup you posted.

When running fast the flames were short and a dull red in colour.
When reduced to an idle the flames were longer and blue in colour.

The red flames flickered but were visible at all times from all exhausts.
The blue flames were intermittent - just ejected every now and then.

None of the flames were bright enough to illuminate the cowlings of the aircraft. This is my experience from a couple of merlin night runs I've witnessed. The only time the aircraft is lit up is when the engine has been overprimed and the full fuel flames are seen pouring out for a few seconds on initial start.

This makes sense since an aircraft lit up to the extent we see in the SoW video would have made a perfect target at night. I know the brightness of the exhausts was a problem at night for pilot vision - in First Light I remember reading that Geoff Wellum couldn't see the runway lights below him at night because strips of metal were attached to the fuselage of his Spit to hide the exhaust outlets from the pilot, partially obscuring his downward vision - he hadn't realised that and thought the runway lights were being switched off every time he flew approach!

[Sutts]

Exactly. In general, hot=blue, cool=red/yellow, plus a flame that's seen directly exiting the piston will be hotter than a flame seen after travelling the entire length of the exhaust pipe.

So, since the colour is a function of exhaust gas temperature, i guess that running on higher power will produce bluer flames. Also, leaning the mixture at night could be done by watching the flames, you just have to lean until the highest exhaust gas temp which means the bluest flame you can get, then enrich it again just a tad from that point.

I might know how the stuff generally works but it don't know what the correct colour for each circumstance is. However, i'm really excited about these features because they give the impression of a real, working machine under the hood. Excellent update!

:grin:




...and the way pilots of prop driven aircraft adjust their mixture today is by, guess what, a temperature gauge that monitors how hot the exhaust gas is. So you're correct generally, except the part where you say it has nothing to do with temperature. This is also not opinion but physics, whatever burns hotter is to the blue/white side of the spectrum and stuff that burns cooler is to the red/yellow side. It's the reason even the stars are not all the same colour. Cheers ;)


Edit: I just saw you corrected it yourself :grin:


Unfortunately, the stills I've captured from the Just Jane Lancaster nighttime runup show exactly the opposite Blackdog......when RPM is high we see short red flames. When idling the long blue flames are ejected intermittently. Could be that this old Lanc just isn't tuned up properly like a flyer would be.

Dunno!

EDIT: Sorry, it was someone else who related colour to engine speed. I agree it is temperature based like you say and the temperature at any RPM will be dependent on the efficiency of the burn...mixture, cold/warm engine, degree of wear in the barrels etc.

[LukeFF]

The sound of the plane is the same as in il-2. Is it just temporary or final?

Did you read Oleg's first post? :rolleyes:

[TeeJay82]

Engine runs with an external program... to me it sounds like your utilizing the a2a`s accusim

is this the case?

[klem]

I need immediatly to run from office.

Please if you find any materials that to show, read, and you own suggestion - write it here.
I and my guys will read it.

I will be back soon. Hope on Sunday.

Try this Oleg

http://www.rogerdarlington.co.uk/Hurricane.html

"Even with the flame shields over the exhaust, I found the flickering blue flames strangely comforting over the water but, once over the French coast, one felt very conspicuous in the night sky". His squadron colleague Morrie Smith makes the same point: "I felt that everyone for miles around could see the exhaust stubs glowing in the night, but the anti-glare cowlings protected the pilot's night vision from this glow".

"As I descended deeper into the cloud, I experienced a frightening phenomenon: the whole inside of the cockpit was lit up by a red glow. My immediate reaction was: 'Fire!' But there was no heat and all my instruments showed everything to be in order, so I ventured to look outside. My two exhaust manifolds were belching out the usual flame, made perhaps a trifle more red and less blue from being throttled back, and this source had illuminated the surrounding very dense cloud. It was an eerie sensation but, once I knew what it was all about, it ceased to trouble me".

Don't forget the glowing stubs :)

[ATAG_Dutch]

So, now I've thought about it.. anytime the engine is running efficiently we should see blue-er flames in SoW.

The less efficiently the engine runs the yellow-er the flame.

That would beg the question, what effects an Aero engines effectivness at burning fuel?

Rubbish fuel?
Altitude?
Damage?
Mixture?

I put question marks because when it comes to engines I find them exactly like women.. I love them, but I dont understand how they work...

Well, I've spent most of my life dealing with engines for a hobby, whether model aircraft, motorcycles or cars. I've also been an aircraft nut since I could walk , and I've never seen a yellow exhaust flame like that shown except from a damaged engine, or one with which I've had to fill the air filter with 'eezy-start' to get it running (which usually meant it was damaged anyway). Even then, the yellow flame soon clears unless the motor is really coked up or has badly pitted valve seats/bent valve stems. Even then the effect wouldn't be uniform for all cylinders. Most primers I've come across are methanol based, which also burns blue/violet.

Hence my question about the primer used. If the yellow flame is indicative of the primer, fair enough. If not, the flame should be blue.

(Actually, I just watched Rudolph's video post again, and the bloke is obviously hand pumping the primer, and, oh look, the flame is still blue!!)

The argument about altitude and RPM is also unfounded as the aircraft was on the ground and ticking over, as were the videos posted.

Like Blackdog, I'm also an amateur astronomer and yes red giants are cool and blue giants are hot. White Dwarfs are very hot and quite nasty, but the exhaust flame of a spit at night should be blue.:)

The MkI, II and IV spits had covers over each pair of exhaust stubs which purportedly produced a degree of 'boost'. It's possible that soot could build up in these somehow and burn to produce a yellow flame, but the ground crew should have been put on jankers for poor maintenance.

I'm beginning to think Mr Maddox does this deliberately just to keep us occupied.:grin:

[addman]

I'm beginning to think Mr Maddox does this deliberately just to keep us occupied.:grin:
The thought has struck me too :)

[Rodolphe]

...


When running fast the flames were short and a dull red in colour.

The red flames flickered but were visible at all times from all exhausts.




Around 08'00" , note the many glowing burnt fragments in the prop wash of this mighty Lanc confirming the bad combustion (dull red) of that transitionnal and intermediate engine power.

http://www.youtube.com/watch?v=k9AGbrGBjQQ&feature=player_embedded#!

...

[SlipBall]

Thanks for the up-date, the grass moving looks cool:grin:

[JG52Uther]

Apparently a merlin 45,I don't see any flames:

http://www.youtube.com/watch?v=cv0Onh6NzPA

And another one:

http://www.youtube.com/watch?v=wIpgk-1OfFU

[Skoshi Tiger]

I need immediatly to run from office.


I often feel like that when I'm at work! ;)

I realy like the way the spitfires suspension reacts in the first video. That little dip of the wing as as the plane turns and comes to a halt. It really gives the impression of inertia and the mass of the aircraft.

Cheers and thanks for the update!

[Sutts]

...




Around 08'00" , note the many glowing burnt fragments in the prop wash of this mighty Lanc confirming the bad combustion (dull red) of that transitionnal and intermediate engine power.

http://www.youtube.com/watch?v=k9AGbrGBjQQ&feature=player_embedded#!

...

Well spotted Rodolphe, I skipped that video for some reason. I notice the same red flames as in the other clip but they appear clearer and longer since there was no external lighting this time. I agree that the engines are probably poorly set up in this case. So...blue flames when running efficiently and redder when the mixture is made richer.

I still see no reflections on the cowlings.

I've taken a few more stills to illustrate in the attached piccy.

[Romanator21]

Apparently a merlin 45,I don't see any flames

That depends on how it's started. These are not typical, but show flames can occur:

http://www.spitfirespares.com/spitfirespares.com/Website%20products%2051%20Spit%20pics/Spitfire%20starts%20with%20flames.jpg

http://www3.pictures.gi.zimbio.com/Eurofighter+Typhoon+Spitfires+Join+Forces+2s9_syXG 3asl.jpg

I think the start-up video is ok. If I had one qualm with it, it is that the smoke of that quantity dissipates very quickly. Either the smoke should be much less, or it should hang around longer if it's going to be that big.

Here's an example, but every video shows the same thing:

http://www.youtube.com/watch?v=FzsJBjbCyvM

3:05

Regarding exhaust flame at night - I will leave color to the experts. I would like to point out that color doesn't always have to do with temperature. Some flames burn green for instance, or purple. I would also like to say that the ambient light from the exhaust seems too strong. While exhaust flames would have been an important factor in finding your enemy at night, I don't think they would paint the side of an airplane bright yellow (or any color for that matter). The same occurs in IL-2 when firing guns (bright yellow glow on side of plane and in cockpit), which I think is not accurate.

Regarding sounds - even in IL-2 they are good, but one that was missed was speed of sound in air. Explosions a mile away are heard instantly. I hope this feature will be implemented in SoW. Secondly, sounds are modified by air flow. If it's a windy or turbulent day, the drone of an engine is going to fade in and out in a random way, with the degree of rise and fall of volume increasing with distance. Thirdly, low frequencies travel farther than high frequencies. So, when listening to an engine that produces an array of frequencies, you will hear a low drone when it is far, and a higher click-clack buzzing when it is near. I can't decide if this is modeled in IL-2 or not, but I'm throwing it up here anyway.

[Richie]

Apparently a merlin 45,I don't see any flames:

http://www.youtube.com/watch?v=cv0Onh6NzPA

And another one:

http://www.youtube.com/watch?v=wIpgk-1OfFU

Those Merlins have those fancy covers over the six stacks though. You can't really see if it's flaming or not. Come to think of it maybe that's why they're on there.

[Abbeville-Boy]

Hi,



2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions





present color would be OK for a cold engine rich fuel startup. does the color change as engine warms and mixture is leaned?
blue with a pointed white center is optimum

[Catseye]

Apparently a merlin 45,I don't see any flames:

http://www.youtube.com/watch?v=cv0Onh6NzPA

And another one:

http://www.youtube.com/watch?v=wIpgk-1OfFU
Blue flame is practically invisible in daylight.
I've seen pics of formula 1 racing where after a crash, the driver is trying to get away from flames engulphing him - the video does not pick up the blue flames.

I've also seen exhausts burning blue but at the last part of the flame they start to flicker yellow.

Interesting topic. In my mind I'm beginning to rationalize briefly yellow turning to blue as the system heats up but that is purely a guess by me and I'm sure Oleg will have the definitive answer after seeing all the info being brought forward.

[Motokiume]

Yet another video - watch for the colours at approx 30 seconds:

http://www.youtube.com/watch?v=g2gefluBLpo&feature=related

[jameson]

Best vid I could find of MH434 a mkIX spitfire with type 66 Merlin engine. From 5.35 to 6.25:
http://www.youtube.com/watch?v=UDZmq2VrcNQ

Any kind of visible flame on startup is very unusual unless this is due to overpriming of the engine. A spitfire in good condition will start with less than one turn of the prop. They can throw out quite a bit of smoke though for a couple of seconds. See here, a mk1a:
http://www.youtube.com/watch?v=tv4SGCtIevE&feature=related

[MD_Titus]

I would go more with Blue...
yep
In all of the accounts I've read, the pilots refer to Blue flames from the exhausts at night.

The flames matching the firing order is very impressive!:grin:

indeed.

thanks for the update oleg

[Baron]

Maby this should indecate to people that Oleg and team are ontop of things:

"We have original table of the exhaust colors by which British crew were need to define is in good or not so good conditions the engine before the flight..."


Meaning maby Oleg and team have more than one colour to play arround with depending on situation.


So maby we could go back to the orginal question:

"My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions"




Amazing how difficoult focusing on the issue at hand can be for some.

[moilami]

Well this is not a british engine but maybe this gives you an idea how it should look like?
http://www.youtube.com/watch?v=4ZzvKCQwWj0

Wow, got a signature!

[baronWastelan]

Sorry Oleg, had a spare hour this afternoon and a new add-on for an old sim, and just couldn't resist...

http://www.youtube.com/watch?v=1tzHTH2Jzhg&hd=1

[pikokk]

sorry for my bad very very bad english

in all benzine engine the exaust flames is blue, benzene vapor create those color, but see yellow/orange flames is caused to "return of flame" (in italiano si dice ritorno di fiamma in inglese non ne ho idea!) this "return of flame" is determined from a not complete combustion of the mixture in the cylinder

[major_setback]

I must say it is nice to see that the hangars are weathered and old looking.

A question about the presentation video 2 weeks ago - will we see English train stations? The one shown with British vehicles passing nearby is Foo'bar's German station (and can be seen on his site).

[PeterPanPan]

Yes, the tape tears when the guns are fired.

Yes, I know it does in the real world. I was just wondering if this will be modelled in SoW. :)

[kendo65]

Yes, I know it does in the real world. I was just wondering if this will be modelled in SoW. :)

Yes. Oleg has said it will.

(I'm sure this was what David603 meant too)

[Insuber]

Yes. Oleg has said it will.

(I'm sure this was what David603 meant too)

Already shown in pics and videos. Red tape goes when guns fire.

[Insuber]

The thought has struck me too :)



I'm beginning to think Mr Maddox does this deliberately just to keep us occupied.:grin:

Same for me, I had vaguely feelings of a dog when the master throws it a bone ...

Anyway from books the flames should b bluish, and the hot exhausts glowing red.

[SQB]

I work on an airfield and this is what i have seen with the oldies (there are 2 spitties, im not sure if they have kept the original engine or not, sorry)

When the engine is started sometimes the flame is yellow and sometimes it goes straight to blue. When the engine is running at low revs the flame is almost invisible and purple, but as throttle increases it goes blue and quite a bit brighter.

Sorry I can't be of more help, this is just what i have seen.

[bf-110]

Flame colour has nothing to do with the angle you view it from or the length of the exhaust pipe, it is nothing to do with temperature either. It simply shows how efficiently the fuel is burning.

If the combustion is burning all the carbon you get blue flames and no smoke. If there's carbon coming out in the exhaust gases then you'll get yellow-er/smoky-er flame.

This is chemistry not opinion.

Does that haves something with complete and incomplete burning?
Lack of O²,etc?

Same for me, I had vaguely feelings of a dog when the master throws it a bone ...



Looks more like a hundred dogs.Sometimes they start to fight...

Anyway,awesome update!The level of details of SoW is beyond any flight simulator.Nearly experimental.
Sometimes I wonder how a machine will be able to handle the complete game.

[yuxinma2005]

Nice update!

[JG1_Wanderfalke]

I´m so sorry, but engine sound is really awfull :(
pls pls pls can we have a authentic one.

[ATAG_Dutch]

I´m so sorry, but engine sound is really awfull :(
pls pls pls can we have a authentic one.

Please read Mr Maddox's first post. He says it is a 'placeholder'.
The sound is La7 from IL2. I'd know it in my sleep.;)

[Bearcat]

Lanc at night (http://www.youtube.com/watch?v=0MMHQmOkiNs&feature=related)

Here is another.. apparently of the same Lanc.. from someone else... but notice around 1:90 or so.. the whiteish blue light from the inboard starboard engine..

[major_setback]

Yes, I know it does in the real world. I was just wondering if this will be modelled in SoW. :)

Yes, it is shown in one of the films from the Russian game show.

Before and after:

http://i4.photobucket.com/albums/y129/major-setback/pres02b.jpg

http://i4.photobucket.com/albums/y129/major-setback/pres03b.jpg

[engarde]

Well this is not a british engine but maybe this gives you an idea how it should look like?
http://www.youtube.com/watch?v=4ZzvKCQwWj0

Haaaahahaha i believe thats coming straight out of the block with no exhaust stubs?

I recall i did that after transplanting a 2 litre Ford engine in my little Mk2 Escort.

Drove it around for a bit with no bonnet/hood and no engine pipe.

Sounded like a demon on a short chain, although when i got back i realized i'd burnt pretty much everything off that side of the engine bay. ;)

Aah good times.

[Hunden]

Thanx for the update but somehow I feel like a cheap date thats been handed half a beer. Love what you gave us though. Realistic or not I like the BLUE.

[Skoshi Tiger]

It's lucky we've got so many experts on this forum especially in the field of chemisty. I on the other hand have only the basic high school level.

If you look at the first minute of so of this video, you'll see the flame changing colour due to the mixture of the fuel and air being burnt. If there is exess fuel in the mixture it will be a highly visible yellow flame, if it's the mixed fuel/air at the correct ratio it will be blue but almost invisible.

http://www.youtube.com/watch?v=IpuVOYRb2pU

In Olegs video we a an engine that has just been started. From the video shown the engine is barely ticking over.

Now the merlin engine had what's called a high overlap cam shaft, which means that the inlet and outlet valves are open at the same time for a long time durring the otto cycle. (It allows fresh fuel air mix to enter the combustion chamber at the same time as the last of the exahust gasses leave the combustion chamber.) This makes the engine more efficient within the engines power band BUT at low revs the engine engine runs rough due to incomplete burning of the fuel air mix in the combustion chamber. It's what known as a 'Lumpy Cam' in automotive circles. It means at low revs there is a lot of unburnt fuel in the exhaust gasses.

Now I know some people here want Oleg to demonstrate a 'Blue Flame' in an update video. I for one, most emphatically, do not want to see this!

Cheers! ;)

[Richie]

That must be one of the Messerschmitts engines that fly in Germany. They're all Buchon switch backs to Daimlers but you'd never be able to tell. A G6 G10 and a G4.

[SJ_Kraken]

-Nice update, but how about sound? It's my idea or is the same original sound of il2?, is only temporal?.


-Best Regards.

[Skoshi Tiger]

-Nice update, but how about sound? It's my idea or is the same original sound of il2?, is only temporal?.


-Best Regards.

Happy first post!

Need to read the first post in the update!

Cheers!

[GF_Mastiff]

Yes Oleg I was going to say my military experience has shown me the most exhaust flames are a bluish hugh.

[Flying Pencil]

It is depending of gazoline, pressure, RPM, and so many other factors... Even at different altitudes it is different really...

We have original table of the exhaust colors by which British crew were need to define is in good or not so good conditions the engine before the flight...

You did your homework, Oleg, just as we expect from you.

The orange flash exhaust would be correct if it is running at idle and too rich with fuel, but at normal power would be blue.

The flash is pretty good, not perfect, but good enough.


2 more comments:
The engine audio needs a lot more work.

Someone needs to cut the grass.


Keep up the excellent work!

S!

[greypeace]

Hi Oleg,
I dont know where to post this query
First post got lost in last week update
Thank for the tip ( from a kind chap )to repost early in the new update so it will be seen ...
Sorry if I am out of place ,

QUERY:
I am finishing a FFB firmware project and I would like to know if BOB 's FFB handling will be compatible with the Microsoft FFB stick on which my firmware is based.
I am only using the "Spring" feature , The most important one ...

Thank you
gb

[mungee]

What about this pic?
Overdid the priming??

[ElAurens]

Over priming, or some issue in the carburetor itself.

That much flame is not a normal thing.

[greypeace]

Hi Oleg,
I dont know where to post this query
First post got lost in last week update
Thank for the tip ( from a kind chap )to repost early in the new update so it will be seen ...
Sorry if I am out of place ,

QUERY:
I am finishing a FFB firmware project and I would like to know if BOB 's FFB handling will be compatible with the Microsoft FFB stick on which my firmware is based.
I am only using the "Spring" feature , The most important one ...

Thank you
gb
Sorry for the double post ,i dont seem to know what I am doing.....

[rakinroll]

Thank you Oleg, and thank you again for videos.

[Ibis]

Thanks for the update Oleg.
Here is a video of a Spit start up taken at Wanaka NZ.


Check at 1.10minutes

Maybe Spit was over primed.

http://www.youtube.com/watch?v=HcSjzNlsvMo

[Richie]

Stack fire...The engine isn't even firing there. Some fuel vapor has clung to the stacks and caught fire. Something like when you're tuning a new..old type.. engine with a carburetor and it back fires and the carb catches fire.

[kancerosik]

definitelly more red than blue . Of course with the engine stopped and cooled

the video isn´t mine but I was there and can see the engine start 3 times

http://www.youtube.com/watch?v=B4X1hiBK8Uk&feature=player_detailpage

[Tiger27]

This reminds me of the discussions about the cannon flames in IL2, as much as some people can be a bit pedantic, it gives me a nice feeling too know that we will have another ten years of forums to read when things get a bit slow at work :cool:

[Sutts]

I realise the main point of the update is the colour of the exhaust flame but I think perhaps what's more import is the extent to which the exhaust flames light up the side of the aircraft.

I've seen two night runs and the exhaust flames (sometimes quite large) didn't have any lighting effect on the aircraft - you just saw the flames - nothing visible behind them.

I think the few night videos posted here confirm that fact. I'm not familiar with the proper terminology but in my view the exhaust flames are not an ambient light source.

Take a look at the night time clip and tell me the RAF would have been happy with an aircraft giving off that much light at night. "Sitting duck" springs to mind.

[KG26_Alpha]

What about this pic?
Overdid the priming??



Over priming, or some issue in the carburetor itself.

That much flame is not a normal thing.

No its normal starting.

And to quote myself

Hi Oleg

You have the flame colour about right for initial start up but probably to fast in engine speed, slower start to run up.

I've seen a few of these engines start up :)

1. Lazy/slow red/yellow flame from fuel primed start up.

2. Blue smoke clearing cylinders with yellow flames to brown/grey smoke.

3. Blue with yellow tips on engine run up and under run.

4. Shut down black/grey exhaust smoke short burst.

If I can find some of my video will e-mail it.

[Seeker]

[QUOTE=Oleg Maddox;203623]Hi,

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions


It actually needs some blue, though I know nothing of computer colours, I've run plenty of short pipe four strokes, and yes, petrol burns yellow in a rich mixture, but as the revs increase the combustion cleans up the flame will become blue.

[stu babes]

Excellent work. Probably less yellow.

RedToo.

ti think youl find that photo is off 85 sqdn

[T}{OR]

No its normal starting.

And to quote myself

Hi Oleg

You have the flame colour about right for initial start up but probably to fast in engine speed, slower start to run up.

I've seen a few of these engines start up :)

1. Lazy/slow red/yellow flame from fuel primed start up.

2. Blue smoke clearing cylinders with yellow flames to brown/grey smoke.

3. Blue with yellow tips on engine run up and under run.

4. Shut down black/grey exhaust smoke short burst.

If I can find some of my video will e-mail it.

While I do agree that the initial engine startup (flames) is too fast, as for the rest - the engine flames should behave depending on how we use the engine. Different mixtures and priming should effect how the flames look (color and volume). Not to mention the overall effects that different usage will have on the engine, like shown in the videos.

[klem]

Duxford 2009 (the size of the pictures is reduced)

These look like startup pictures to me Harti. btw it's a griffon engine but the merlins look similar on initial startup.

[MD_Titus]

i like the wealth of knowledge that is displayed here sometimes. from a brief video and question on flame colour we get a huge discussion on possible engine states etc, actually learnt quite a bit. so has the question been answered with another one - will the flame colour reflect different levels of fuel/air mixture and engine condition, and if so, what are the factors at play in the video to give this particular flame?

[Osprey]

He also explained why blue exaust in most instances is incorrect yet most here want it to be blue?

Maby the refferance in books saying the colour is blue is because they saw the flames in an angle looking straight down the stacks so to speak (from an angle and from behind) , like oleg explained, flames are blue just at the beginning of the outlet and gets more yellow the longer the stacks are.

just guessing.

We have videos showing it, some have seen it and most have read it in the accounts from pilots and crew that flew.

The Halifax I and II had terrible trouble with their positions being given away by blue exhaust flame from the merlins. They tried to cover it with metal guards but they glowed red instead. Only when the hercules engines were fitted in the III was the problem resolved.

I would like to hear the argument and evidence as to why it should be red and yellow rather than blue.

[klem]

Hi,

I promised to post videos some time.
Here is the first of them.

1. Engine start. Flame and smoke effect. Every start is different (in realtion to emulation of real engine cylinders work by a program).
Sound is currently a place holder. Unfortunately I wasn't able to record in a track at the moment maximal settings (some unpredictable bug in recording of video need to be found and eliminated )

http://www.youtube.com/watch?v=G836qqOhhZ8

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions

http://www.youtube.com/watch?v=KTx5v8jeFdw


I have many airshow daytime films of Hurricanes, Spitfires and the Buchon (merlin-engined) 109 taxying and low passing. There are no flames visible in any of these films. They would often give yellow 'flowers' of flame on startup (see other posts) so your video seems generally correct for daytime conditions except the exhaust gases seem to have too much "thrust" on that initial startup.

[The Kraken]

I would like to hear the argument and evidence as to why it should be red and yellow rather than blue.

It's about the startup effect and not the exhaust glow of running engines. Whether we'll see a blue glow at night, possibly even depending on engine settings as explained in some posts (probably overkill though), is a different issue. Fingers crossed :)

Anyway, nice details and I'm especially happy to see the subtle reflectivity on the plane skin again, which has been absenst in all screens since months.

[Krt_Bong]

You know on one of the other sim forums they're having a discussion about why an HP 0/400 might still be able to fly with no wings and only 1 engine, I guess we should count ourselves lucky all we got is what colour the exhaust flames should be

[merlin66]

Thanks for the update Oleg!

About the flames, it seems to me there are two main effects:

1. Yellow / red flames from excess fuel exiting the exhaust sometimes during startup. This is so visible it can be seen both at day and night, as shown in pictures in this thread. This is probably so bright it will illuminate the plane at night.

2. Blue flames: at night you can see that the exhaust itself is has a blue glowing color, at least at high power settings (see the Reno video earlier in this thread). This isn't very visible in daytime. Pilots often describe seeing only the blue exhaust flames of the enemy planes at night.

Edit: So my conclusion is:
- The startup flame in your first video looks perfect (and this should illuminate the plane if seen at night)
- The yellow flames in your night video: If this is supposed to be the second effect (engine running smoothly), the flames should probably be more blue and not illuminate the plane that much. But my main reference is the Reno video earlier in this thread, maybe running at lower power settings with shorter exhaust pipes (Spitfire vs. Sea Fury) gives more yellowish flames.

Here is another example of the first kind of flame:
http://www.youtube.com/watch?v=uNXGDi79aPw

[ATAG_Dutch]

It's about the startup effect and not the exhaust glow of running engines.

Sorry, but the motor in the dark is running, not starting up. The timing between the flashes is too even. Also, if it was starting up, we'd presumably see a similar long flame to the daytime start clip.

Skoshi does have a point in the cylinder scavenging / cam overlap being a possible source of unburnt fuel, but all the video and literary evidence screams 'blue!';)

[The Kraken]

Sorry, but the motor in the dark is running, not starting up. The timing between the flashes is too even. Also, if it was starting up, we'd presumably see a similar long flame to the daytime start clip.

Hmm good point about the 2nd video. To be honest I'm not sure what exactly it's showing; the engine indeed runs evenly but with very low RPM (or time is slowed down). At any rate I have a hard time imagining the final game will show all planes at night with a strobe light effect around the engine...

[flyingblind]

I don't think an exact colour match could ever be achieved as every monitor shows a slightly different colour anyway. The only comment I would make about the first video compared with the real life videos people have posted is that in real life the yellow flames are produced by a cloud of unignited fuel/air mixture being expelled from the engine and subsequently being lite by the burning exhaust gas once the engine has fired. As such no pressure is involved and the flames are quite 'lazy' in appearance. In Olegs game video the yellow flames are being expelled with considerable force. In the second video it looks like the engine is idling before takeoff rather than running under power so exhaust gases could well look more yellow than blue.

[T}{OR]

I don't think an exact colour match could ever be achieved as every monitor shows a slightly different colour anyway. The only comment I would make about the first video compared with the real life videos people have posted is that in real life the yellow flames are produced by a cloud of unignited fuel/air mixture being expelled from the engine and subsequently being lite by the burning exhaust gas once the engine has fired. As such no pressure is involved and the flames are quite 'lazy' in appearance. In Olegs game video the yellow flames are being expelled with considerable force. In the second video it looks like the engine is idling before takeoff rather than running under power so exhaust gases could well look more yellow than blue.

+1000

And it also depends on the mixture / priming of the engine in the first place. The biggest remark is just that - on low RPM when starting an engine the flames should be 'lazy', because un-ignited fuel is coming out of the engine cylinders and thud burns outside it - vertically. Only when the engine actually starts the flames get expelled horizontally (axially with the each cylinder exhaust pipe) as in many videos posted here accompanied with a transparent blue flames. Not to mention the vast amount of smoke as well (but this effect is done nicely).

[smink1701]

Oleg,

Flame looks fine...only lasts a few seconds anyway. The visuals we've seen are amazing. I hope you put equal effort in getting the sounds right. IMHO :twisted:

[FG28_Kodiak]

Have found this table for the Allison V-1710 Models 'E' and 'F' (from Allison Service School Handbook ALD-SSH-5) I know its not a Merlin
;)
http://img525.imageshack.us/img525/6734/allisonservicehandbook.jpg

[JAMF]

Mr. Maddox, a quick question on last weeks update; Was the map in the FMB a temporary version, or does the SoW map have structures from after the war? (Like the Basin de L'Atlantique at Gravelines, WSW of Dunkerque?)Final size. No changes. We can't satisfy everything. There are limits in size by memory, limits of other type, etc. We was need to cut by this way. Originally plannen way more greater. But there is a great contradicitons between what to put in terms of detailization and what would be the size due to this detalization. Again it is impossible to make everything withouit going for compromisses.
In Il-2 in every map we had also compromisses. Repeat: in every, is it crimea or moscow map, etc. And we were need to cut other possible historical action as well due to this fact .

I'm hoping the following images clarify my question more:

http://img257.imageshack.us/img257/3529/dunkirkgravelinesbasin.jpg

Today : "Safe Harbour" from heavy seas to the left, docks to the right, near city centre
http://img808.imageshack.us/img808/5248/dunkirkbasin.jpg

Aerial '44. Harbour and sea access near city centre. Would overlay the image above to the right quarter, no channel going left.
http://img89.imageshack.us/img89/2940/dunkirk44s.jpg

[ElAurens]

No its normal starting.



You know Alpha, in all the times I've seen Merlins start up, on Hurris, Spits, and P51s, and a Lancaster, I've never, ever seen a stack fire. Not one. I know it happens but it is far from normal and not a common thing.

Can we agree that it should not happen at every start up?

I know that there are those that would like to see it every time, and they would be wrong.

[Mysticpuma]

Oleg.....Spitfire flames in the dark and they are blue!!


http://www.youtube.com/watch?v=QhFAwSk9Vqg


Cracking find. I searched for a clip like that, but found nothing.

BTW, not all engines start the same. Here's a clip I found which makes me think that a night-time startup, if similar conditions were applied to a Spitfire, could be a really impressive pyrotechnic show!

http://www.youtube.com/watch?v=kXpQv4Pu6BM&feature=related

Cheers, MP

[Rodolphe]

...


More reading about exhaust flame vs detonation ~ grade of fuel used.


http://users.teledisnet.be/web/mfe39146/PIF521.jpg



http://users.teledisnet.be/web/mfe39146/PIF522.jpg



...

[Blackdog_kt]

Have found this table for the Allison V-1710 Models 'E' and 'F' (from Allison Service School Handbook ALD-SSH-5) I know its not a Merlin
;)
http://img525.imageshack.us/img525/6734/allisonservicehandbook.jpg

That's very useful. It also confirms what most people have been saying, that the temperature of the exhaust gas and the subsequent colour is a consequence of a variety of factors that can affect fuel burn. High or low power, mixture settings, etc, all seem to play a role.

The most interesting part in the picture you posted is the possibility to diagnose problems or verify the correct operation of the engine.

For example, leaning the mixture. In today's general aviation piston engined aircraft, leaning is usually done by moving the mixture lever back until you see the EGT (exhaust gas temperature) gauge reach a peak, if you lean any further it will start dropping again. So, for example let's say the peak EGT occurs with the mixture lever at the 75% forward position. If you move it forward/backward from that position the EGT will drop. What the pilots do is start leaning and watch for the reversal in the needle (watching it rise, then drop again from over-leaning), at which point they enrich it a bit to get it back to peak EGT.
Then, they enrich a bit further until the EGT drops a set number of degrees, which is usually specified in the aircraft manual. This is usually stated like this: "lean mixture as follows: for best cruise enrich to 50 degrees below peak EGT, for best economy enrich to 30 degrees below peak EGT". Peak EGT is not a constant but that doesn't bother us. For example, if running 75% power the EGT on the whole (which includes the peak value) will be higher than what we would get if running at 60% power, but all we care about is "catching" the highest temp on the gauge and enriching a set number of degrees from that, not what the highest temp actually is.

So, why do we care? Because i think most aircraft in WWII didn't have an EGT gauge, but the picture you posted showed the same method being possible to use by watching the exhaust stacks.
Lean mixture on the allison gives a blue flame, rich mixture gives a red flame near the stack and a blue flame further away but it says the blue flame moves closer to the stack as the mixture is corrected. Finally, the correct mixture has the blue flame near the stack and the red flame behind the blue one.
So, one could theoretically lean the mixture until he sees too much of a blue flame that signifies the peak EGT (the higher temperature of exhaust gas, which gives off the blue glow). Then, they would have to enrich it a bit as described before, judging when to stop by the appearance of red flame behind the blue one, but not going as far as having the flames reversed (blue after red) because that would signify an overly rich mixture.

Excellent stuff!

[major_setback]

Have found this table for the Allison V-1710 Models 'E' and 'F' (from Allison Service School Handbook ALD-SSH-5) I know its not a Merlin
;)
http://img525.imageshack.us/img525/6734/allisonservicehandbook.jpg


Excellent information find!
It shows that all types of fires can be seen depending on what is happening in the engine.

Unfortunately I doubt that the game engine has been programmed with allowance for these variations if Oleg is only just now asking for information on stack-fire types.

Oleg: I hope I am wrong. Am I?

[Ltbear]

Many engine heads know the exhaust smoke is a good indicator about how the state of an engine is...

If you test run engines in a test bench without the exhaust pipes on the colour of the flames are also a decent way to identify any problems...

My observations of engines i have worked on

idle should be yelow with a blue base

i work with RPM`s not power settings..

at 2800 RPM`s with no load on the engine it should be yelow with a small red base

at 2800 RPM`s with load its a 50/50 yelow and red

at max settings and full work load it should be blue base with red and yelow..

This is what i know from carburator engines...

When a engine works the tempeture will change etc....

Overprimed engines will make a yelow flame, normaly with werry dark grey or black smoke puffs....

But there is more to it.....how well do the oilring scrape the cylinder wall etc....a small ammount of black smoke doing start up can indicate a small ammount of oil left in the cylinder.....thats actualy ok as long it stops when the engine gets to operating tempeture...

Whitesmoke is also ok...again if it stops at operating tempeture

White and blue`ish smoke on startop is a no go....that is both water and oil and thats bad no matter if it stops or not, that is a mixture of oil and water...and that should not happen.....

I personaly dont care about colours, the awsome part for me was the working of each seperate cylinder....that is cool, and that realy give my hope up for the shot up cylinders...German and british plane dont like that, but later on the yanks radials aircooled will love that...we might get the **holy crap i landed on 4 cylinders**

Spits and 109`s wount like loosing cylinders....the 190 will fare abit better on it....man just the ideas about the different things that can go wrong with engine hits....

woooooot!!!

LTbear

[Jumo211]

Please , click the YouTube link to directly watch this video in bigger screen and HD
in order to see all details :cool:

http://www.youtube.com/watch?v=EsAXDB-sV8w

[II/JG54_Emil]

Wow, we can have this stuff already in IL2?!?

Now that would be cool to have mod/developement in 4.10m.

[KG26_Alpha]

Schhhhhhh

Its the unmentionables

:)

[Tree_UK]

Thanks for the update Oleg, would it be possible next week to show some footage of fully weathered fighters having a dogfight, this would be most pleasing. Many thanks.

Peace to you all this christmas.

[Richie]

Sounds good Tree.

I'm trying to find that aviation artwork of the English boys sitting on a wood fence as they watch a Spitfire coming towards them with it's gear down as it's about to land on the field behind then. I always think to myself I wish I was sitting on that fence.

[Richie]

OOO found it

[Jaws2002]

Hi,

2. Effect of exhaust flame at night time. Emulation of each cylinder exhaust in relation to emulation of real engine cylinders work by a program.
My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions



Since you said you have the colors for the other types of flames, i guess we are only talking about the "yellow" flame.
I think would look better in with a more orange tint. That may also make the greenish reflections a bit more "warm".

Thank you for the update.:-P

[Sutts]

Since you said you have the colors for the other types of flames, i guess we are only talking about the "yellow" flame.
I think would look better in with a more orange tint. That may also make the greenish reflections a bit more "warm".

Thank you for the update.:-P


Fair enough but there really shouldn't be any reflections on the aircraft skin. I've yet to see one piece of evidence showing reflections on the panels of the aircraft from exhaust flames. While it looks nice, that kind of illumination would have been completely unacceptable in wartime, not to mention the effect on pilot vision.

[Oleg Maddox]

Here is a Merlin engine being started, but one see no flames at all, maybe only visable during night time?
http://www.youtube.com/watch?v=yprfH5ZsAHk&feature=related

Here is more sound of prop then of engine really, especially with High RPM.
But thanks for the sample

[Oleg Maddox]

...


More reading about exhaust flame vs detonation ~ grade of fuel used.


http://users.teledisnet.be/web/mfe39146/PIF521.jpg



http://users.teledisnet.be/web/mfe39146/PIF522.jpg



...

Yes, we have it. but also with the drawn samples :)

[Oleg Maddox]

Oleg.....Spitfire flames in the dark and they are blue!!


http://www.youtube.com/watch?v=QhFAwSk9Vqg

Sure, with high RPM and right mixture.

[Sutts]

Oleg,

In terms of the initial startup flames I think you have the perfect colour already, no more red required.

I attach comparison shots from the previously posted P-51 Old Crow startup against the flames in your video. You have them spot on I think.

Once the engine is running it looks like red/blue is the expected colour though. I haven't seen any yellow flames from a running engine yet and the colour chart previously posted only mentions yellow flames when the spark plugs are defective.

Would be nice to occasionally see the large lazy flames caused by an overpriming stack fire too.

Thanks:grin:

[fireflyerz]

Lets not get too carried away... PLEASE -Watch the whole vid to see what happens as engine revs are increased and decreased.

http://www.youtube.com/watch?v=Xs_qt4GCj4A

[T}{OR]

Lets not get too carried away... PLEASE -Watch the whole vid to see what happens as engine revs are increased and decreased.

Very nice find!

And a good point. It is important to note the engine RPM changes. When they occur, it affects how the fuel is burning in the engine. Variable and constant RPM's are two completely different processes happening inside the cylinder. In other words - when on constant RPM (provided we have the ideal mixture) the engine is burning fuel just like it should have, while with variable (changing) RPM the mixture and overall fuel burning process is far from ideal.

i. e. - for the very same reason there are two different fuel consumption figures in cars: one for driving in a city where throttle changes are frequent and fuel consumption is higher, and another for highway driving where fuel consumption is much lower.

[Stefem]

Yea, a bit or red and blue would make it more realistic

[SlipBall]

Have found this table for the Allison V-1710 Models 'E' and 'F' (from Allison Service School Handbook ALD-SSH-5) I know its not a Merlin
;)
http://img525.imageshack.us/img525/6734/allisonservicehandbook.jpg


Excellent find FG28_Kodiak:grin:

[Tbag]

Oleg&Team, thanks for the update. Completely OT but a very interesting document for the future:

http://www.cockpitinstrumente.de/archiv/Dokumente/ABC/a/Alliierte/US%20Armament%20in%20the%20Air%20War.pdf

[Tbag]

and another one:

http://www.cockpitinstrumente.de/archiv/Dokumente/ABC/a/Alliierte/US%20Air%20Combat%20Records%20WW%20II.pdf

[KG26_Alpha]

You know Alpha, in all the times I've seen Merlins start up, on Hurris, Spits, and P51s, and a Lancaster, I've never, ever seen a stack fire. Not one. I know it happens but it is far from normal and not a common thing.

Can we agree that it should not happen at every start up?

I know that there are those that would like to see it every time, and they would be wrong.


Every time I've seen Merlins start from cold they have the lazy flame effect from priming.

Some times depending on the lighting conditions you wont see too much of this effect, the camera though does see it very well.

I'm fortunate to be a member of FOD (Duxford) so I practically lived there a few years ago and saw a lot of aircraft in preparation for shows and being started for testing etc etc, Merlins especially as there are so many of them at Duxford :)

[Sutts]

Lets not get too carried away... PLEASE -Watch the whole vid to see what happens as engine revs are increased and decreased.

http://www.youtube.com/watch?v=Xs_qt4GCj4A

Perfect find fireflyerz, thanks for posting. Must have had the mixture bang on in this run up, lots of blue and more blue. A brief flash of orange/yellow flame on initial start - just like in the 1st Oleg video.

A red flame from a single stack at one stage I noticed.

I was so glad when they turned the lights off. No illumination of the side panels at all really - maybe very slight at one point but just immediately around the stacks. Best video yet.

Cheers

[Auger73]

Perfect find fireflyerz, thanks for posting. Must have had the mixture bang on in this run up, lots of blue and more blue. A brief flash of orange/yellow flame on initial start - just like in the 1st Oleg video.

A red flame from a single stack at one stage I noticed.

I was so glad when they turned the lights off. No illumination of the side panels at all really - maybe very slight at one point but just immediately around the stacks. Best video yet.

Cheers

The flame color is a product of the temperature (that whole quantum-mechanics stuff). For these engines one of the biggest factors is the mixture.

A leaner mixture will result in higher temperature (and higher power) - which results in flames on the blue side.

A richer mixture will result in lower temperature - so the flames go to the orange/red side.

In my experience with Cessnas, you would start the engine at full rich fuel mixture. I would think most engines would be started at full rich, and leaned afterward.

In a new engine, this would probably result in yellow flames on startup. Once the engine is leaned, it would go toward blue.

The only thing about these videos is they are showing old aircraft with old engines. I would suspect that the conditions of individual engines (even different cylinders on the same engine) and the fuel systems probably play into why some videos show a variety of colors.

I would hope that different flame colors are modeled (blue - orange/red), depending on the engine conditions.

[undercut]

Nice, I love the how you can see the effect of the prop torque effects on the aircraft when throttled up too fast.

[TheGrunch]

The only things I have to say echo what people have said before; the smoke in the startup video disperses too quickly and the exhaust flames should not light up the side of the aircraft in the second video.

[heywooood]

smoke disperses differently depending on what it consists of, relative atmosphere, humidity, temperature and the like - and so does the color pf the flame vary depending on the fuel, the mixture of fuel/air, the last time the engine was fired and the way it was shut down, etc...

so many variables that to deduce whether a single video render depicts the effect accurately or not is ludicrous -

ever see a stack fire? that is why at airshows you always have a guy or two with fire extinguishers standing by any warbird that is about to have its engine started.

the color and strength of the flame can be from practically invisible - to a massive yellow flame and fire. The smoke volume and color can be just as variable.

should Oleg try to cover the entire range of this effect? Of course not - the resources are better used elsewhere. Should there be some variation between night and day, cold engine vs refuel rearm restart? Probably

Will everyone be pleased with whatever these effects end up as? No

This is just another example of a developer trying to add small details that bring life and character to a simulation and having it blown out of proportion utterly by a few professional smoke and flame specialists ad alta

[Romanator21]

You know on one of the other sim forums they're having a discussion about why an HP 0/400 might still be able to fly with no wings and only 1 engine, I guess we should count ourselves lucky all we got is what colour the exhaust flames should be

:grin: True!

[Richie]

I don't think we need to search for anymore exhaust flames. That video has it all in one.

[AWL_Spinner]

This is just another example of a developer trying to add small details that bring life and character to a simulation and having it blown out of proportion utterly by a few professional smoke and flame specialists ad alta


Oleg asked for opinions, he got opinions; I think there was a fair amount of worthwhile input in the pages of this thread, some of which I'm sure Oleg found useful. He can sort the wheat from the chaff.

Did it ultimately overshoot the mark? Yes.

Was it nonetheless a good discussion? Yes.

I know I've learned a lot! Expect more of the same next week :)

Cheers, Spinner

[Doogerie]

a littel more red a littel orange less yellow. but it looks good dude get that track bug sorted and get it to the stors asap DO LIKE

[JimmyBlonde]

From Jack Torrence, 43 Squadron Hurricane II night intruder pilot.

"Even with the flame shields over the exhaust, I found the flickering blue flames strangely comforting over the water but, once over the French coast, one felt very conspicuous in the night sky". His squadron colleague Morrie Smith makes the same point: "I felt that everyone for miles around could see the exhaust stubs glowing in the night, but the anti-glare cowlings protected the pilot's night vision from this glow".

Hope this helps!

[TheGrunch]

<snip>

You're perhaps right about the smoke (I watched the video again), but as for the second part I am referring to the lighting effect of the exhaust flames in flight in the second video and not the ambient lighting effect of a stack fire at engine startup. I find the mod effects videos a bit gimmicky in that they presumably depict a stack fire on every startup, but they're still a bit more convincing than the SoW videos so far in terms of the smoke and the exhaust flames, not that we're really sure what mixture/RPM settings are depicted in the second SoW video, which of course makes all the difference.. Not that it matters about the eyecandy IMO as long as the engine simulation in SoW is better. :) Still, I'd love it if Oleg & Co. took a good look at the Seafire video above and the various others posted and did their best to replicate the differences in the various engine settings/engine temperatures' effects in the sim, although not necessarily now. I'm not gonna call myself a "smoke and flame specialist", but I'd say that it's pretty much essential that at least some kind of effect exists around exhaust flames for night-fighting to be playable in the sim, which is something that I'm really interested in. Of course, anything like that could wait until we have some kind of reason to have realistic effects in this department, i.e. more appropriate flyables for night-fighting, like hopefully the Beaufighter at some point? Although the second video's cool, I think it would make it a bit too easy to spot aircraft at night compared to how difficult it's been described to be in reality.

[Azimech]

Thirdly, low frequencies travel farther than high frequencies. So, when listening to an engine that produces an array of frequencies, you will hear a low drone when it is far, and a higher click-clack buzzing when it is near. I can't decide if this is modeled in IL-2 or not, but I'm throwing it up here anyway.

It is, but almost impossible to configure. I had this only in 2006, when somehow I had the correct settings. After I reinstalled windows XP and used the same IL2 installation as before, the effect was gone. I've spent hours trying to find the correct setting but no-one can tell me how.


And for exhaust flames, here's something completely different:

http://www.youtube.com/watch?v=5pMHZaMFw9c

[KG26_Alpha]

Lets not get too carried away... PLEASE -Watch the whole vid to see what happens as engine revs are increased and decreased.

http://www.youtube.com/watch?v=Xs_qt4GCj4A

Wrong engine.

Totally different fuel system.

Why bother posting this its totally irrelevant to a Spit MkI Merlin

[Richie]

It's still a carburetor. So what if it's a Griffin. Mixture is mixture.

[TheGrunch]

Wrong engine.

Totally different fuel system.

Why bother posting this its totally irrelevant to a Spit MkI Merlin

Somehow Alpha, I don't think even the most Aspergers-ridden detail-hound is expecting Maddox Games to individually model the effects of mixture and RPM, etc. on exhaust flame size and colour for each individual aircraft. I think that we're just hoping that maybe, if there's time at some point in the future, there will be a general effect that's about the same for each aircraft that changes the size/colour/presence to some degree. So...somewhat of an unfair criticism of fireflyerz' post I feel.

[fireflyerz]

Triple-choke Bendix-Stromberg updraught carburettor...

Plus I was posting the vid more so to help Oleg get the amount of flame exausting at differant engine revs correct.

[philip.ed]

Triple-choke Bendix-Stromberg updraught carburettor...

Plus I was posting the vid more so to help Oleg get the amount of flame exausting at differant engine revs correct.


Ignore it; if Oleg wants to use it, he won't ask Alpha.

[KG26_Alpha]

Triple-choke Bendix-Stromberg updraught carburettor...

Plus I was posting the vid more so to help Oleg get the amount of flame exausting at differant engine revs correct.


Sure, with high RPM and right mixture.

Look its simple just post relevant info.

You might as well post any night time exhaust flames vid if you think in your terms as its simply not relevant unless its a Spit MkI

If you don't see that then carry on.

And thanks for the name calling, shows your a real class act.

[philip.ed]

Well, there's a lack of relevent period videos, in colour, showing the exact transition. Considering the team are willing to model a modern version of England and France, I think Jafa's video is a nice compromise.

[Luftwaffepilot]

Considering the team are willing to model a modern version of England and France

What? Isn't this supposed to be a WWII sim?

[KG26_Alpha]

Well, there's a lack of relevent period videos, in colour, showing the exact transition. Considering the team are willing to model a modern version of England and France, I think Jafa's video is a nice compromise.

Why do we need this when there's perfectly good examples flying today.

[philip.ed]

Why do we need this when there's perfectly good examples flying today.

To be devil's advocate, do they use exactly the same fuel, etc? I can see what you're saying, a mark 1 spit from today is better to compare to than a seafire, but it's hard to find suitable videos.
Just my thought. Personally I think it's best to average out the effects seen in some videos, and then base this strongly around historical references. The pilots from the time would have had a pretty good idea themselves, and many have documented the effect ;)

[SlipBall]

Basically all internal combustion engines are the same in the compression chamber. As far as any visible flames coming from the exhaust stack. A properly burnt mixture may not show any flame at the stack, because the fuel was burned up already during the compression power stroke firing. A cold engine on the other hand, would be showing colored flames during the exhaust stroke for a bit...kind of cool feature, but I would prefer it only on the start up in game.

[II/JG54_Emil]

Right now I´m just thinking why doesn´t Oleg call Duxford and tells them he the master blaster that will get more visitors to Duxfords Flying Legends all he needs from them is the different colours of of different planetypes with the engine in different conditions and various lights.

Better then us guessing around if this is the right fuel/footage/idea/whatever.

[fireflyerz]

Good greif Alpha, you have quoted me but havent bothered to read what I wrote about the vid I posted "READ WHAT I WROTE" :rolleyes:

[KG26_Alpha]

Good greif Alpha, you have quoted me but havent bothered to read what I wrote about the vid I posted "READ WHAT I WROTE" :rolleyes:

I read it

You didn't read Olegs response to earlier similar video.

I even quoted Oleg and what he said to earlier similar video of yours

So whos not reading the thread posts ?

If your are interested in this thread read my earlier posts they accurate from years of experience.

My last post in here regarding this, I'm done with it.

Wrong plane wrong engine same effect I have seen many times on MKI......... but value to this thread...........zero

http://www.youtube.com/watch?v=frTA1PVmY_w&feature=related

[sorak]

I read it

You didn't read Olegs response to earlier similar video.

I even quoted Oleg and what he said to earlier similar video of yours

So whos not reading the thread posts ?


My last post in here regarding this, I'm done with it.

Thanks for letting us know you are done with it.

[winny]

Woo hoo.. yet another update thread ends in name calling..

Too many people who think that opinion and fact are the same thing.

Come on girls, play nice. I have a handkerchief if anyone needs to dry thier eyes.

[Trumper]

:) Regardless of what mark,make and model, BoB is the first of a line of sims which will incorporate different types and locations.
Any useful info is good for the future as well as today.

[I/ZG52_Gaga]

flames red or blue ... whatever ...

it only needs to be deemed down a bit and it is cool

or ....

use the modification that has all the nice different stages if you like ..

but please !!!!

can we move on ?

can we? eh? :)

[philip.ed]

:) Regardless of what mark,make and model, BoB is the first of a line of sims which will incorporate different types and locations.
Any useful info is good for the future as well as today.

Well said! ;)

[Richie]

To be devil's advocate, do they use exactly the same fuel, etc? I can see what you're saying, a mark 1 spit from today is better to compare to than a seafire, but it's hard to find suitable videos.
Just my thought. Personally I think it's best to average out the effects seen in some videos, and then base this strongly around historical references. The pilots from the time would have had a pretty good idea themselves, and many have documented the effect ;)

I think all of you are taking this way too far. Blue flames instead of red or yellow and that's about it...Blue. Even the Daimler Benz flames are about the same blue and I don't think Maddox is going to fart around for the next six months getting his flames just so. Going back to 1940 to compare high leded fuels and their flames with today's low led fuels and their flames..Hilarious! Is it a flight sim or a flame sim?

[EinsteinEP]

Well done, Oleg et al! Storm of War is looking very nice indeed! I'm sure the community in large will really be thrilled with the attention to details. I know I can't wait!

I have a couple of DeviceLink questions (apologies if I've missed a relevant thread on this topic):

1) Will Storm of War support DeviceLink or some similar interface for data logging and sim-pits?

2) If so, could it I be so bold to make a humble request for a few parameters in addition to those currently available in DeviceLink 1.00?
- True Airspeed
- True Altitude
- Outside air temperature
- Static air pressure
- Angle of attack
- Total thrust force
- Total drag force

These parameters would be very useful in evaluating aircraft performance (specific energy, lift curves, etc.) and are similar to those parameters taken (or derived) on test flights of real aircraft.

[philip.ed]

I think all of you are taking this way too far. Blue flames instead of red or yellow and that's about it...Blue. Even the Daimler Benz flames are about the same blue and I don't think Maddox is going to fart around for the next six months getting his flames just so. Going back to 1940 to compare high leded fuels and their flames with today's low led fuels and their flames..Hilarious! Is it a flight sim or a flame sim?

I know what you mean.
I have always viewed it like this: there will always be forum members with specific knowledge in certain subject areas (like me with my RAF flight-gear collection) and when the teams asks for help in that area, there will usually be a lot of info, but not all of it is necessarily needed.
However, IMHO, more is better than less ;)
But I agree, it's just an effect and one won't notice if there is just a tiny bit too much blue...

[BigC208]

Nice flamebait Oleg, it worked.

[AdMan]

yellow/orange/red at startup or when damaged

blue/white during normal operation

/thread

[kalimba]

Nice flamebait Oleg, it worked.

:grin::grin::grin: !!!!

Oleg must be laughing outloud at home tonight: Look at this , honey, ! I told you it would take less that 2 days before they get at each others throat arguing about..guess what this time ? exhaust flame color at night!!!...hahahaha!
Next week, I will ask them about tire pressure....It will be a carnage !!! Can't wait till next update !

;)

[Necrobaron]

Hi,

My question to community: isn't it too yellow? Maybe to add a bit red color in a mix with yellow? It is tunable really, so I would like to listen suggestions

http://www.youtube.com/watch?v=KTx5v8jeFdw

I agree that the color is somewhat too yellow (I agree with what Adman said above), but the biggest thing I've noticed is that the flash from the exhaust on the side of the fuselage is overdone. It should be minimal to nonexistent.

[proton45]

If I was Oleg I would post up-dates that, I knew, where flawed...that way the nitpickers are too busy squabbling over "red or blue flames" (example), as opposed to moaning over release dates, computer spec's or whatever subject they think will get the forum community in a "tizzy"... lol


Its time to keep the "kiddies" busy...the adults are working.

;) ;) ;)

[Richie]

I know what you mean.
I have always viewed it like this: there will always be forum members with specific knowledge in certain subject areas (like me with my RAF flight-gear collection) and when the teams asks for help in that area, there will usually be a lot of info, but not all of it is necessarily needed.
However, IMHO, more is better than less ;)
But I agree, it's just an effect and one won't notice if there is just a tiny bit too much blue...

Sorry, I was a little harsh Phillip lol

[lbuchele]

:grin::grin::grin: !!!!

Oleg must be laughing outloud at home tonight: Look at this , honey, ! I told you it would take less that 2 days before they get at each others throat arguing about..guess what this time ? exhaust flame color at night!!!...hahahaha!
Next week, I will ask them about tire pressure....It will be a carnage !!! Can't wait till next update !

;)
I'm still imagining the picture and laughing...A LOT.:-P

[Richie]

I'm trying to think back to the 60s. wasn't gasoline a yellow colour back then?

[Wutz]

If I was Oleg I would post up-dates that, I knew, where flawed...that way the nitpickers are too busy squabbling over "red or blue flames" (example), as opposed to moaning over release dates, computer spec's or whatever subject they think will get the forum community in a "tizzy"... lol


Its time to keep the "kiddies" busy...the adults are working.

;) ;) ;)
Ha ha well even with mid forties I then hope I will never become an "adult" as you put it.
Going by some posts one could drop all input, at the most only writen signs of awe are acceptable......Thank god your type is not an admin, or forums would be a dead place.

[Sutts]

I don't see this as a squabble at all. It's been a useful and interesting discussion with opportunities to learn new things. Oleg asked whether the flames were too yellow on the running engine. From all the evidence and experience posted here it is clear that yellow flames are generally only expelled on initial start up or when the engine is damaged in some way.

Correct me if I'm wrong but I haven't seen one video here showing regular yellow flames coming from a running engine. All are either blue or red once the initial startup is complete. Also no night shots show the side panels being lit up by the exhaust flames. That backs up my personal experience from 2 night runs on a Lanc and a Merlin Spitfire.

I think the thread has done its job well.

[Tree_UK]

Oleg, avoid forum arguments about start up flame colours by posting up a video of a dogfight with nicely weatherd aircraft.This would bring us all together in admiration of your fine work, and it would be a great crimbo present to all your loyal fans and supporters :grin:

oh and without any place holders if possible.

[JimmyBlonde]

http://www.youtube.com/watch?v=7GDqmHXFgo4

Seems to be a sort of orangey brown on this one...

[IbnSolmyr]

I don't see this as a squabble at all. It's been a useful and interesting discussion with opportunities to learn new things. Oleg asked whether the flames were too yellow on the running engine. From all the evidence and experience posted here it is clear that yellow flames are generally only expelled on initial start up or when the engine is damaged in some way.

Correct me if I'm wrong but I haven't seen one video here showing regular yellow flames coming from a running engine. All are either blue or red once the initial startup is complete. Also no night shots show the side panels being lit up by the exhaust flames. That backs up my personal experience from 2 night runs on a Lanc and a Merlin Spitfire.

I think the thread has done its job well.

+ 1. I totally agree.

It's the first time, since about 5 years, that i post. My first few words will obviously be for Oleg : I love you !!! Oups sorry, i exaggerate a bit ! ;-) But i love your work. Long life to you and your team... All your work philosophy is perfect to my mind, and i'm sure BoB will be astonishing, awesome... Please don't change anything to your working way, you and your team are fantastic ! However, that's right it becomes to be very hard to stay patient, because we wait for some years and now, we know that the release date is for soon (please don't tell me something else or i die at this second). But at least we know that we wait for the best simulation ever ! And yet many many many thanks for your kind work, for Il-2, for your attitude. You're the best. Because you do better than that we could dream... Thanks again.

[klem]

Lets not get too carried away... PLEASE -Watch the whole vid to see what happens as engine revs are increased and decreased.
...........................

Very nice example showing the persistence of the blue flame at night and why nightfighters like Hurricanes had the exhaust stack guard over them.

That's a Griffon engine btw but I expect the Merlins were similar especially according to anecdotal evidence from the actual pilots.

[airmalik]

Please , click the YouTube link to directly watch this video in bigger screen and HD
in order to see all details :cool:

http://www.youtube.com/watch?v=EsAXDB-sV8w

Wow! I'm not an expert on this but the flame and smoke effects in this video are very convincing. I'll be very happy with similar effects in SoW.

[Sternjaeger]

I wanted to post this before but just didnt have time:

As Oleg explained, the flame output of an exhaust is affected by factors like temperature and pressure. Flames visibility is due mainly to lighting factors (it'll be harder to see flames on a sunny day), but they're always there (bear in mind that what you see is the output of the avgas combustion straight from the combustion chamber!).
Exhaust fire shouldn't be confused with backfire though, which is an external combustion of a too rich mixture which causes flames like this
http://air-and-space.com/20070818%20Camarillo/DSC_0863%20P-51D%20N514DK%20right%20front%20crop%20l.jpg

Oleg, I love the work you're doing, the attention to details as usual is surprising and comes from a man who obviously has experience with aviation, my humble suggestion is to keep the flames towards the red/blue spectrum more than yellow, since the temperatures involved are far higher than a "yellow flame" when it comes to exhaust output. Another important aspect is to keep them subtle (in terms of transparency/alpha channel) but visible from distance (thinking of the Zerstoerer night fighters spotting the engine exhausts of Lancasters at a certain distance).

[BP_Tailspin]

Oleg must be laughing outloud at home tonight: Look at this , honey, ! I told you it would take less that 2 days before they get at each others throat arguing about..guess what this time ? exhaust flame color at night!!!...hahahaha!
Next week, I will ask them about tire pressure....It will be a carnage !!! Can't wait till next update !

http://www.cubpilot.com/Tspin/lol_2.gif

[150GCT_Veltro]

About map.
Dimension are enough but i agree about Duxford. Would have been better have it.......... Why? You know it.

However my question is. Would be possible to fly this map also online or we'll have dogfight style maps with islands ecc. ecc.?

[alexei1789]

Hi Oleg and thanks a lot for the weekly updates !
looks like we're gonna have a wonderfull flight sim.

it's my first post, and please apologize if the subject has been already chatted, i haven't found the answer.

QUESTION:
- The screenshots show fuel tank selector knob in cockpit... will fuel cunsumption influence centering/trimming of the airplane ?

- a suggestion: if this very realistic management is really implemented in the released game, it would be nice to have precise doc on the DVD, i.e. admission pressure and rpms for different flight condition, time to deplete a fuel tank,... the kind of data that is in the flight manual :)
otherwise even solo flying shall be difficult !

-will we have random failures ? (not only engine, but gun jamming, radio down, gear or flaps innoperative...)
they might have been common it the crash-programm building of materials during the war.

Thanks a lot
Alexis

NB: i don't mean there's too much realism, i'd just like to have the information to run "smoothly" the engine.:-)

[kalimba]

I don't see this as a squabble at all. It's been a useful and interesting discussion with opportunities to learn new things. Oleg asked whether the flames were too yellow on the running engine. From all the evidence and experience posted here it is clear that yellow flames are generally only expelled on initial start up or when the engine is damaged in some way.

Correct me if I'm wrong but I haven't seen one video here showing regular yellow flames coming from a running engine. All are either blue or red once the initial startup is complete. Also no night shots show the side panels being lit up by the exhaust flames. That backs up my personal experience from 2 night runs on a Lanc and a Merlin Spitfire.

I think the thread has done its job well.

You are right Stutts. In every new Fryday Update we do learn a lot about WW2 from lots of well informed members...:-)
But it doen't take long before somebody disagrees with someone's opinion, and instead of politely making a comment,replies with a harsh and useless remark, often beeing a personnal attack....As a father of 2 young boys, I think that my overall patience :rolleyes: is well challenged everyday in the real world, so when I come here to enjoy good company and admire Oleg's work, it is very irritating to witness such a behavior... And in this forum , it is exactly like at home : kids play togheter, happy with the new toy, and you can be sure it won't be long before screams and tears...;)

Salute !

[Daniël]

Hi Oleg and thanks a lot for the weekly updates !
looks like we're gonna have a wonderfull flight sim.

it's my first post, and please apologize if the subject has been already chatted, i haven't found the answer.

QUESTION:
- The screenshots show fuel tank selector knob in cockpit... will fuel cunsumption influence centering/trimming of the airplane ?

- a suggestion: if this very realistic management is really implemented in the released game, it would be nice to have precise doc on the DVD, i.e. admission pressure and rpms for different flight condition, time to deplete a fuel tank,... the kind of data that is in the flight manual :)
otherwise even solo flying shall be difficult !

-will we have random failures ? (not only engine, but gun jamming, radio down, gear or flaps innoperative...)
they might have been common it the crash-programm building of materials during the war.

Thanks a lot
Alexis

NB: i don't mean there's too much realism, i'd just like to have the information to run "smoothly" the engine.:-)

No.3 : Should be. If I remember it right:) I don't excactly know what things will random fail, but I think some things.

No.2 + 3 : Would be very nice:grin:

[Richie]

I wonder if grass will move in prop wash. I was kind of hoping in the first video that that one Spitfire would swing right around and blow the grass.

[Spinnetti]

So, some may know already, but "proper" color of flame is not just what you like, but depends on many factors including Fuel type and Mixture, and mixture varies by type and amount of boost. Actual flame color is relative to combustion temperature and oxygen concentration. Generally speaking, the leaner the mixture, the "bluer" the flame, and the richer, the more yellow it is. At full boost, you tend to run richer to avoid burning a piston, and it should be more yellow. At cruise, it should be leaner, and thus bluer. For game purposes, I would probably have a couple settings - yellower for start up and full power, and bluer for all other settings - Important to note, but generally the only time you see any flame at all is on a missfire. If the engine is running in tune, there should be little missfires, and thus not much flame (although even a 2% missfire rate is still about 11 missfires/sec on a 16 cyl at 2000 rpm if I did the math right). The flame occurs when the unburned mixture hits the hot exhaust and combusts in the exhaust stack.... This is the general truth, but I'm sure experts could refine the exact details.

[Sternjaeger]

let's not forget that the flaming alternation of different exhausts is more visible at low revs/idle. When the engine is on cruise the blue flames are more constant from all the exhausts, as the engine is working at higer revs.

[AMVI_Superblu]

awesome...maybe a little red or orange would be good.
Agree!!
Thanks for update Oleg ! :)

[Richie]

I wanted to post this before but just didnt have time:

As Oleg explained, the flame output of an exhaust is affected by factors like temperature and pressure. Flames visibility is due mainly to lighting factors (it'll be harder to see flames on a sunny day), but they're always there (bear in mind that what you see is the output of the avgas combustion straight from the combustion chamber!).
Exhaust fire shouldn't be confused with backfire though, which is an external combustion of a too rich mixture which causes flames like this
http://air-and-space.com/20070818%20Camarillo/DSC_0863%20P-51D%20N514DK%20right%20front%20crop%20l.jpg

Oleg, I love the work you're doing, the attention to details as usual is surprising and comes from a man who obviously has experience with aviation, my humble suggestion is to keep the flames towards the red/blue spectrum more than yellow, since the temperatures involved are far higher than a "yellow flame" when it comes to exhaust output. Another important aspect is to keep them subtle (in terms of transparency/alpha channel) but visible from distance (thinking of the Zerstoerer night fighters spotting the engine exhausts of Lancasters at a certain distance).

This has nothing to do with the engine running normally it's just raw fuel on fire. That engine probably isn't even running yet. The wind from the prop would blow it out.

http://www.youtube.com/watch?v=EoyN29O8UoE

[Sutts]

So, some may know already, but "proper" color of flame is not just what you like, but depends on many factors including Fuel type and Mixture, and mixture varies by type and amount of boost. Actual flame color is relative to combustion temperature and oxygen concentration. Generally speaking, the leaner the mixture, the "bluer" the flame, and the richer, the more yellow it is. At full boost, you tend to run richer to avoid burning a piston, and it should be more yellow. At cruise, it should be leaner, and thus bluer. For game purposes, I would probably have a couple settings - yellower for start up and full power, and bluer for all other settings - Important to note, but generally the only time you see any flame at all is on a missfire. If the engine is running in tune, there should be little missfires, and thus not much flame (although even a 2% missfire rate is still about 11 missfires/sec on a 16 cyl at 2000 rpm if I did the math right). The flame occurs when the unburned mixture hits the hot exhaust and combusts in the exhaust stack.... This is the general truth, but I'm sure experts could refine the exact details.


That sounds all very good but please show us a video where these yellow flames are being ejected by a running engine or point to the entry in the WWII exhaust flame colour chart where yellow flames are referred to. That chart covers everything from weak to rich mixtures and a whole lot of other scenarios including engine damage. Strange how yellow flames don't even get a mention - orange on a damaged engine but everything else is red and blue. I know it's for an Allison engine but I can't believe it differs much from any other inline carburated aero engine.

The only yellow flames I've ever seen are from raw fuel burning in the stacks of a flooded engine and an initial burst of yellow/orange flame when the engine first fires up.

I'd be happy to be proved wrong as I like the pretty yellow flames :grin: but the overwhelming evidence so far is against yellow flames from a running engine.

[major_setback]

The big question is this: Will be be able to over-prime the engine in the game?

[Richie]

That's a very good question. I think because of the fuel injection of the German fighters the Allied aeroplanes will have more fun with the flames.

[WTE_Galway]

This has nothing to do with the engine running normally it's just raw fuel on fire. That engine probably isn't even running yet. The wind from the prop would blow it out.



Half right ... once an engine fires the manifold vacuum and exhaust pressure extinguish any carby or stack fires.

The main, well documented, issue on WWII war-birds was the glow of the hot manifolds at night, interfering with pilot visibility (especially in high mounted manifold designs like the hurricane and spitfire) and making the aircraft a target to night fighters. A number of different design features were tried to mask this manifold glow.

[AndyJWest]

Yes, you have a point. It isn't the exhaust that is glowing, but the exhaust manifold. Inevitably this will be at a significantly lowe temperature than the exhaust itself, so where the exhaust is flame may be blue, the manifold will be yellow or red.

[Chill31]

Oleg,

If you havent already recieved enough info at this point, I want you to know that the flame color coming out of the exhaust of a running engine like that would be more blue! than red or yellow. The flame is burning hot and mostly clean, so it comes out with a nice blue flame at night. In the day, you wont see it.

On engine start, the only time you will get the yellow/orange flame out the exhaust is if the engine is too rich and it spits out unburnt fuel that burns exiting the exhaust stack. In that case you will get a lot of orange/yellow fire coming out for a short time. I was on the wing of a P-51 when that happened and it does get warm...

Note: its easiest to over prime with the electric fuel pumps found on P-51s and the like.

*edit The short stacks in most of the videos lets you see a lot of blue flame...more than if the full length stack was in place. If you leave the exhaust as is with no blue, you really will be misrepresenting the way exhaust looks coming out of the stacks at night...

http://www.youtube.com/watch?v=g2gefluBLpo&feature=related
This video (previously posted) shows what I would expect to see coming from the exhaust at high power settings at night...see it at 0:30 video time

http://www.youtube.com/watch?v=UDZmq2VrcNQ
This video shows over priming at about 5:30. His first couple of attempts to start were underprimed and he didnt keep it running with additional priming.

Also, when you go from high power to low power rapidly, you will get some light popping and orange flame as the rpm comes down.

Good luck with your great project!
Chill31

*edit, looking back at all of the posts, it looks well covered!

[Sternjaeger]

This has nothing to do with the engine running normally it's just raw fuel on fire. That engine probably isn't even running yet. The wind from the prop would blow it out.

http://www.youtube.com/watch?v=EoyN29O8UoE

well first of all is mixture, not raw fuel, on fire; second, if you READ what I wrote you might well see that that's exactly was I was talking about ;)

[Sternjaeger]

That's a very good question. I think because of the fuel injection of the German fighters the Allied aeroplanes will have more fun with the flames.

...what do you mean exactly?

[T}{OR]

...what do you mean exactly?

When burning fuel in the cylinder, if we're talking about an ideal process - you need exactly the same amount of fuel and air in your mixture. Since space in cylinder is limited, there is only so much air and fuel you can put in there (if we're not talking about turbo or supercharging). And certain amount of fuel requires exactly certain amount of air (I forgot the exact ratio but I can dig it up if you want, I have it one of my books).

The biggest downside of carburetors is that they can produce such ideal mixture only on certain RPMs, or RPM ranges. While direct fuel injection is much more flexible and can provide the engine with better mixture on all RPM ranges.

I am talking theory here, but I believe this is what Richie meant with:
That's a very good question. I think because of the fuel injection of the German fighters the Allied aeroplanes will have more fun with the flames.