Friday 2010-12-17 Dev. update and Discussion

[T}{OR]

Originally Posted by swiss

What would you call what a Diesel does?

Diesels are much less sensitive to knocking, although it is also an undesired effect.

Knocking in Diesel engines occurs when there are either low temperatures inside a cylinder, there is a low load on the engine (I think this is a proper translation) or with fuel that has very low cetane number. Cetane number is a measure of a fuel's ignition delay - the time period between the start of injection and start of combustion (ignition) of the fuel. If the delay is too long, the fuel will ignite when there is already too much fuel inside a cylinder - resulting in a sudden reaction accompanied with strong pressure waves and a very loud noise.

The air in Diesel engines has to be compressed below the minimum level (when compressing air its temperature rises) in order for the fuel to ignite when entering a cylinder. Before modern fuel injection, early Diesels had a combustion chamber inside a cylinder where Diesel fuel would first ignite and spread across the rest of the cylinder - this is the reason why they were so loud (very high pressures inside the cylinder and overall unbalanced/unequal burning process). In early '90-s fuel injector pumps capable of rapid dual injection in one process were introduced. This lowered the noise, and improved the burning process significantly.

Nowadays with Common rail systems (which compress the fuel up to 2000 bar) the fuel gets injected up to 5 times when the piston is at/or close to the TDC, further improving the burning process inside the cylinder. This is one of the reasons why they are so quiet and even more efficient today.

[Splitter]

Originally Posted by T}{OR

My first guess was compression (maybe something to do with different engine types and program modeling processes inside it) - but then again, we won't know for sure until Oleg tells us.

COMP - if MP is for Manifold Pressure, what does CO stand for?

I hardly believe that pilots could manipulate Manifold vacuum (or engine vacuum) other by different throttle settings.

Well, Manifold Pressure (MP) should depend on throttle and mixture. As you rise in altitude, you have to play with the mixture to get the best MP...unless the aircraft is set up to handle mixture automatically somehow. (I know you know this so we are probably just in the middle of a language thing here)

It would be tremendous if Oleg modeled the characteristics of different engines for MP though. There are ramifications for running lean or rich at a given altitude.

Just think of trying to follow your opponent in a dogfight, changing altitudes, and having to also get your mixture right for maximum MP as you go through a 10,000 dive or climb.

Splitter

[Bloblast]

Nice pictures.

Exhausts only visible for starting and at night to make irt realistic.

[T}{OR]

KG26_Alpha - does 'Alfa' have something to do with your call-sign?

Originally Posted by Splitter

Well, Manifold Pressure (MP) should depend on throttle and mixture. As you rise in altitude, you have to play with the mixture to get the best MP...unless the aircraft is set up to handle mixture automatically somehow. (I know you know this so we are probably just in the middle of a language thing here)

It would be tremendous if Oleg modeled the characteristics of different engines for MP though. There are ramifications for running lean or rich at a given altitude.

Just think of trying to follow your opponent in a dogfight, changing altitudes, and having to also get your mixture right for maximum MP as you go through a 10,000 dive or climb.

Splitter

I see your point now. And you're exactly right - having different Manifold intakes affecting engine performance (MP or engine vacuum) simulated, not emulated would be simply awesome. I don't doubt that we will have different MP's for each engine, IL2 already had that.

A bullet hole rupturing your intake manifold and affecting engine performance, imagine that... But we're probably asking for too much here since programs that model this today are very complex (i.e. AVL BOOST).

Most people don't know this, but engine block in a sports car is (usually) the same as the one found in a road car. The design of intake and exhaust manifolds make all the difference (i.e. BMW).

[II/JG54_Emil]

The flames are too bright, Oleg.

Well done Oleg,

Looking forward to a big christmas present from you.

[Ploughman]

Really nice detail, quality. Thank you.

[ElAurens]

I think Oleg is just having a little joke at the expense of the nit pickers.

No WW2 aircraft that I have ever seen fly, and I've seen a lot of them, ever had visible exhaust flames while in flight in daylight.

Not one, ever.

Oleg is an engineer and pilot, and he knows this as well.

Or, this is just an NKVD psy-ops mission to keep the competition distracted.

[Insuber]

Originally Posted by Osprey

Alfa lol - says it all.

I hope you skimmed the head or you'll be doing it again soon

You are OT ... and you probably ignore that the Common Rail was developed originally by Fiat-Magneti Marelli, and first introduced an Alfa Romeo 156 2.4 JTD in 1990 ... a great car and an innovative diesel engine. An incredible piece of engineering, my friend.

Back to topic:

Dear Oleg,

Flames look great now. I'm slightly tired of minor details. Please give us a bigger bone to gnaw at ... a Bf.109 video with the latest gun smoke and muzzle flash, or damage model, or ... you know waht I mean ...

Cheers,
Insuber

[T}{OR]

LOL, you may have a point there ElAurens.

I believe that this over exaggerated effects have been posted for a different reason - to show the effects what different mixture/throttle/RPM/etc. has on the exhaust. I agree, with a proper mixture setting their visibility in broad daylight should be minimum/non existent - unless when starting an engine (as shown on various videos - well documented). And this can be fine tuned after the process in the engine/cylinder has been properly modeled into the game.