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

[changai]

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...

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 !!!

[Flanker]

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

[AdMan]

Originally Posted by 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.

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

these people seem to make sense

[ATAG_Dutch]

Originally Posted by AdMan

these people seem to make sense

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

[Blackdog_kt]

Originally Posted by Oleg Maddox

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!

Originally Posted by 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.

...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

[Sutts]

Originally Posted by Blackdog_kt

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!






...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

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]

Originally Posted by Flanker

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?

[TeeJay82]

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

is this the case?

[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