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

[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.

[Wutz]

Originally Posted by 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.

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.

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

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]

Originally Posted by 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.

+ 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.

Originally Posted by 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.

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 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 !

[proton45]

Originally Posted by Wutz

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.

I dont think your really getting my point...lol

[T}{OR]

Originally Posted by W32Blaster

well not as simple as that.

The ideal mixture is about 14:1, also called lambda=1.

Almost correct. The ideal stoichiometric mixture ratio is 14,7:1 => or 15:1. When we're talking in mass, not volume.

There are two different lambdas in petrol (Otto) engines: lambda(air) & lambda(charge)*.

*not sure if this is the correct technical term in English.

In a petrol engine lambda 1 should always be constant (=1), whereas lambda(charge) can go up to 7 (with supercharged and turbocharged engines), otherwise it also equals 1.

Lambda of 1.0 is at stoichiometry, rich mixtures are less than 1.0, and lean mixtures are greater than 1.0.


Like Azimech, I am also curious of what carburetors are you talking about. The advantages of direct fuel injection over carburetors are numerous. If not, car engines would be using them even today.

Originally Posted by Sternjaeger

erm... no, in a nutshell: mixture has different ratios, which need to be varied according to your altitude (leaner/richer mixture), besides a 50/50 mixture ratio would probably send your valves into orbit (Disclaimer: just wanted to make a joke here, please don't take it literally and start posting copy/paste engineering blabber..)
What Richie said just doesn't make sense: engines won't produce different flames if they're direct injected or carburator injected. Or maybe I got it wrong in the first place.

Fair enough. I forgot to write one thing - at ground level. Or even better: at 20° C & 1,013 bar (Standard atmospheric pressure: the conditions at which every engine is constructed and tested).

As for the rest (at least to my understanding, I am more into car engines), there is no such thing as 50/50 mixture. Maybe that is a phrase used by pilots and maintenance crews - they usually don't follow correct technical terms anyway. What I am trying to say (and to comment on your reply), there is an ideal ratio needed for the fuel inside the cylinder to burn most efficiently / completely (as previously mentioned). As you go higher air density is decreasing. Thus (in non supercharged engines) you need to lower the amount of fuel inside the cylinder to achieve the desired ratio or else you risk engine damage and various other things I do not want to get into now. The added downside of that is that engine power drops as well. To compensate for that - superchargers were invented. They compress air so that you can have the very same atmospheric pressure inside your cylinder as if you were flying on sea level. They can also be used to increase engine power (this is the easiest way to do it) - compress the air enough and more fuel can be put in the cylinder.

I could go on, posting diagrams, formulas etc. - but even 100 posts would be enough...

Anyway, what Richie meat was something else. With carburetors you can't get this ideal stoichiometric mixture ratio of 15:1 throughout whole RPM range because most carburetors are tuned for a certain RPM. This results in imperfect chemical reaction when fuel is burning inside the cylinder - hence probably more variable flames coming out of the exhaust, especially when changing RPM.

Originally Posted by Spinnetti

ideal mixture is still basically the same at any altitude. The difference is that the air density decreases as you go up, requiring mixture adjustments to maintain the same air/fuel ratio. Some planes had auto compensation, but most did not, so mechanical tune and operator capability also come into play here.

Absolutely true. What I posted above. ^^

Originally Posted by Letum

I have a sneaky suspicion that Thor might know what he is talking about when it comes to engines...

I sure hope so...

[W32Blaster]

My Statemant was you can´t say it that Easy: 'Fuel Injection is working better than a carburator in terms of providing the RIGHT mixture for all operating conditions. '
Not which Technologie is best used to gain the goal of ideal mixture under all operating conditions!

Originally Posted by T}{OR

Like Azimech, I am also curious of what carburetors are you talking about. The advantages of direct fuel injection over carburetors are numerous. If not, car engines would be using them even today.

Let´s say youll have a Pierburg 4A1 Carburator with ECU for fully closed loop control of a 3-Way Katalyst System and you compare it with a early k-Jet-Tronic, guess which one is more sophisticated in terms of providing right mixture for all operational state.

Originally Posted by Azimech

The main problem with a carburetor: it's very hard to distribute the mixture to all cylinders equally. Plus fuel injected engine are less prone to icing, they have a faster throttle response and are easier to start when cold.

Now youre talking about a difference between mixture is built internal Cylinder vs external like in Intake Manifold or Carburator.
As long as you are not building mixture via direct injektion you always will put extra parameters to be recognized.