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zyss

Question about ASh-82FN's supercharger

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Hi, everybody.

 

In wiki Shvetsov ASh-82, the "Supercharger" said that:"Single-stage, One TK-2 two-speed centrifugal type supercharger on early production. Two TK-3 two-speed exhaust gas-driven forced-induction compressor on FN and FNV models".

 

Many years ago, I had read a article about Lavochkin series in WWII, it said that in 1945, La-7 late models has increase ite performance in hight altitude, so it is ture that ASh-82FN has "gas-driven forced-induction compressor" model in used?

 

Is that mean La-5FN and La-7 used TK-2 two-speed centrifugal type supercharger ASh-82FN, and La-9 and La-11 used Two TK-3 two-speed exhaust gas-driven forced-induction compressor ASh-82FN?

Edited by zyss

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I don't know of any ASh-82's with a turbo, I think they were all variously single or two stage superchargers with either a single or two speed drive.  The F, FNV and FN did not use turbos, and a turbo wouldn't fit in an La-5 anyway.  There's an IL-14 (Crate) near me that's powered by ASh-82T's and it's got the muffler exhaust on it.  I think what there is to read has lost a fair amount in translation. 

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20 hours ago, chuter said:

I don't know of any ASh-82's with a turbo, I think they were all variously single or two stage superchargers with either a single or two speed drive.  The F, FNV and FN did not use turbos, and a turbo wouldn't fit in an La-5 anyway.  There's an IL-14 (Crate) near me that's powered by ASh-82T's and it's got the muffler exhaust on it.  I think what there is to read has lost a fair amount in translation. 

If we look the picture about La-5FN, La-7, La-9/11, we will find that La-7/9/11 has a exhaust port after the engine cool air outlet each side, but La-5FN has not, I try to see the engine cool air outlet in IL2 BOS, and found that  La-5FN engine's cylinder exhaust direct in air respective. So the exhaust port in La-7/9-11 may be your mentioned "muffler exhaust"?

 

The date I had ever see were said that ASh-82FN has a single stage superchargers with two speed drive, but I think "the late version ASh-82FN has two TK-3 turbo" is not without cause, although it may has lost a fair amount in translation. The article I read mention that La-7 late models has increase its performance in hight altitude, I don't know there is other way to "increase its performance in hight altitude" expect let the engine has better power output in hight altitude. And as a long range fighter ot protect Tu-4, the La-11 also need better power in hight altitude.

 

The engine in USSR often keep a model in many years, but it was improve many in these years. Like T-34's engine V-2-34, from T-34-76 to T-34-85, it still called V-2-34, but it has changed a lot, even some core parts has been improved much, just for better performance and life. So may be ASh-82FN has turbo model in Lavochkin series used. And it also may be only a single stage superchargers with two speed drive in ASh-82FN until it discontinued.

Edited by zyss

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The external difference between the La-5F and La-5FN (along with the La-7) engine installations is basically the La-5F exhaust is collected 7 into 1 on each side (being a 14 cylinder engine) with a visible stack opening behind the aft edge of the cowl flap and the La-5FN exhaust has 5 stacks under each cowl flap with the top and bottom stacks of the 5 attached to 2 cylinders each (the La-7 changed to 7 a side).   It's a similar looking exhaust to the BMW 801D.  By ending the stacks just short of the end of the cowl flaps (keeping them hidden) the designer was using the exhaust to draw air out of the cowling which, in turn, would draw air in the cowl inlet for better ground cooling.  As far as I know, no turbos were part of any La-5/7/9/11 production but the TK-3 turbo setup was tested as you note, and it sounds like the La-7 used a single stage (maybe two speed?) supercharger with a couple of the (apparently small) TK-3 turbos feeding it (making it two stage overall) resulting in the La-7TK but the it was not produced.  The turbos apparently forced a relocation of the oil tank (to behind the cockpit?) and the reduction of weapons to a single gun and it sounds like there were cooling issues.  As for variations in altitude performance between production aircraft that can be accounted for by different supercharger stages and their gearing.

 

I only mentioned the "muffler exhaust" because that's the only production exhaust system variation other than the traditional collected or jet exhaust I'm aware of on the M-82.  I think it's what we would call "augmenter tubes" here in the USA which work to draw air through the cowling and they can muffle the sound as well.  That's what the look like to me on the IL-14 anyway. 

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