Friday 2010-12-17 Dev. update and Discussion

[T}{OR]

Originally Posted by Sutts

I'm pretty sure COMP or CO stands for Compressor i.e. the Supercharger gear setting - Hi, Lo or Neutral I suppose...but I think the early Spits had single speed, single stage superchargers.

The only thing is that "COMP" was on the Ju-88 screen. I have to agree, Compressor indeed sounds as it may be what it stands for.

[CRO_Adriatic]

Sory fo my english...
Maybe explosion wos wrong word, "ekspanzija" in my languge, if it is expazion in english, well, it is not my profesion to talk about it...
http://hr.wikipedia.org/wiki/Eksplozija

On race cars and motorbikes we can see it during day, also whan you squezze the engine in way it is not ment to be used, flames are normal...

[Il2Pongo]

So my post about the main wheel of the 109 not being flush with the wing was deleted because it was out of context?
Really? A comment on the picture posted by the dev is not in context
What kind of "moderation" is that?

[Insuber]

Originally Posted by Il2Pongo

So my post about the main wheel of the 109 not being flush with the wing was deleted because it was out of context?
Really? A comment on the picture posted by the dev is not in context
What kind of "moderation" is that?

In my opinion it was due to the angle of view; to my brain it looked flush, but I admit that the perspective was weird.

[Splitter]

Originally Posted by T}{OR

The only thing is that "COMP" was on the Ju-88 screen. I have to agree, Compressor indeed sounds as it may be what it stands for.

Yep, that actually makes more sense. Good catch,
Sutts. I still hope that manifold pressure it accurately modeled as part of the better complex engine management....which effects exhaust color too I guess .

Splitter

[Goanna1]

To Oleg and Co.
Amazing level of detail that you and your team are bringing to this new sim.
Fantastic effort - greatly appreciated

Have a happy Christmas and an even better New Year for 2011

[T}{OR]

A quick summary after watching all the videos posted here, and following the discussion.

Lets not get too carried away...

Precisely that. Like someone already stated that these flames are deliberately overdone.

There are few factors we should consider when talking about (visible) engine exhaust flames:

1. All videos show planes standing or taxiing on the ground.
2. Although visible on many videos, most of us will agree that they are barely visible - or invisible during daylight.

Thus I will point out to three videos which IMHO more accurately represent what should (can) be seen in real life and thus in the game.

"Seafire night ground run" - watch how high RPM affects engine exhaust:

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

The thing everyone forgot to mention is a very fast stream of air which is blowing over the exhaust stacks (with higher RPM) - undoubtedly much faster and colder once the plane is airborne => further reducing the exhaust flames length because of the fast air stream and also a small portion due to forced convection (cold air cooling the exhaust pipes).

Just like Oleg said:

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...

"Spitfire MH 434 - Part 3/5" - this, I believe is how the flames should be represented in the game, starting from 5:30 (fast forward) first the engine start is shown and then camera shows directly into the exhaust stacks:

http://www.youtube.com/watch?v=UDZmq2VrcNQ

After slightly over primed start the only visible flames are during engine start (due to some fuel left from previous unsuccessful attempts). Once the engine has been started watch how there are no flames exiting the exhaust pipes, even when RPM is increased - although they are visible under the right angle (when looking directly into the exhaust pipes like shown in the video).


And last, the most important video IMO... "Bf 109 Stack Flaming" - posted by Richie, which although doesn't feature exhaust flames, it shows exhaust smoke when changing throttle:

http://www.youtube.com/watch?v=48uziQoniI0

If I would have to choose between the right colored exhaust flames and correctly represented puffs of smoke when changing throttle => I would without a doubt choose the latter because it impacts gameplay and is overall more important feature.

[Richie]

A picture of a 109 G-4 low on a darker day with no flames.

[SlipBall]

(quote)T}{OR
If I would have to choose between the right colored exhaust flames and correctly represented puffs of smoke when changing throttle => I would without a doubt choose the latter because it impacts gameplay and is overall more important feature.


I agree, there's something about turbo's that causes a dark smoke after a quick throttle increase...even in todays world with on road vehicles and their modern engines. So I like the idea of the 109 having that behavior

[T}{OR]

Originally Posted by SlipBall

I agree, there's something about turbo's that causes a dark smoke after a quick throttle increase...even in todays world with on road vehicles and their modern engines. So I like the idea of the 109 having that behavior

Pressure-charging might indeed have a bit increased effect on the smoke puffs during throttle changes. Unless I am mistaken, WW2 planes had only superchargers, not turbochargers.

Combustion during constant RPM is totally different than one during variable RPM. The reason for this is rapidly changing and unequal ratio of fuel and air in the cylinder (variable mixture) - accompanied with black puffs of smoke coming out of the exhaust manifold. Once you set on an desired RPM it takes the engine few seconds to 'stabilize'. Fuel consumption is also much higher during these frequent throttle changes, when compared to running at constant RPM (i.e. just like city / highway driving).

Just like you said - the best example are trucks, when the driver adds power it is always accompanied with thick black smoke coming out of the exhaust. Once it is driving with a constant speed, there is barely any smoke coming out of the exhaust. As far as turbos and truck engines... sometimes it takes up to 2-3 minutes for the exhaust gases to 'stabilize' and spin the turbo for it to have a desired effect.