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

[Rodolphe]

Originally Posted by changai

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. ; )


...

[Flying Pencil]

Originally Posted by Oleg Maddox

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!

[mungee]

What about this pic?
Overdid the priming??

[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.

[Sutts]

Very impressive effects Oleg, thanks. 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.

[smink1701]

Looks like my thread did the trick

Thanks Oleg

[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=B4X1h...yer_detailpage

[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.

Originally Posted by 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.

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.

[KOM.Nausicaa]

Originally Posted by speculum jockey

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.