Radiator/cowling flaps

[palidian]

What effect do the Radiator/cowling flaps positions have?

[fruitbat]

open they cool the engine, but increase drag, so you go slower.

[palidian]

That is what I thought, however I have not noticed that effect.

Second according to pilots I have talked to, one could run at full power and not overheat. WEP and idling in the runway would cause problems.

[fruitbat]

Originally Posted by palidian

That is what I thought, however I have not noticed that effect.

Second according to pilots I have talked to, one could run at full power and not overheat. WEP and idling in the runway would cause problems.

1), just cause you haven't noticed it, doesn't mean it isn't there. Most planes run on avg around 20-25kph slower with rads full open, and don't cool no where near as well with them closed....

2) That statement is to general. Ask them to try it in a climb.... You might get away with it in fast level flight, but if you think you can just firewall the throttle and forget it, your in for a shock.

[WTE_Galway]

Originally Posted by palidian

Second according to pilots I have talked to, one could run at full power and not overheat. WEP and idling in the runway would cause problems.

What are they flying ? There are very few liquid cooled 2000 hp V12 aero engines around these days for example. Even less big radials. Modern engines in that power range are usually turboprops.

If they are GA pilots they are likely to be flying something like a Cessna or Piper powered by a Lycoming O-360 (or very similiar engine) which is a 150 odd hp air cooled horizontally opposed 4 cylinder (the same configuration as a VW Beetle) and they DO overheat in a sustained performance climb.

If you want to try an in-game aircraft where the difference is apparent fly the Lagg 3 low and slow. The low speed handling suffers radically with cowls open.

[IceFire]

Originally Posted by palidian

That is what I thought, however I have not noticed that effect.

Second according to pilots I have talked to, one could run at full power and not overheat. WEP and idling in the runway would cause problems.

You'll find overheat is a bit more realistic in the next patch (4.11) and running at 110% all day long will cause serious overheat that will necessitate reducing throttle and opening the radiators.

Radiators definitely reduce the speed of the aircraft and most certainly cool the engine quicker but it isn't always an instantaneous effect.

[palidian]

This comes from WWII pilots that when in combat would go full mil power and never have an issue. I have several WWII airplane and engine manuals, and they give lots of warnings, but nothing about running at full mil power. The manual states no more than 5 minutes at WEP or Take off power. Water injection helps cool the engine, if cooling was an issue than the water injection would be started earlier. In addition the higher up you get the colder the air is, it is also thinner however.

The ME262 over heats at 100%, jet engines generally do not get hot (so to speak, at least not to start melting things.) due to there nature.

I will test the cowling effects more.

[IceFire]

Originally Posted by palidian

This comes from WWII pilots that when in combat would go full mil power and never have an issue. I have several WWII airplane and engine manuals, and they give lots of warnings, but nothing about running at full mil power. The manual states no more than 5 minutes at WEP or Take off power. Water injection helps cool the engine, if cooling was an issue than the water injection would be started earlier. In addition the higher up you get the colder the air is, it is also thinner however.

The ME262 over heats at 100%, jet engines generally do not get hot (so to speak, at least not to start melting things.) due to there nature.

I will test the cowling effects more.

In reading Pierre Closterman's The Big Show he often mentions the aircraft engine overheating. Particularly when pushed hard the Sabre would get very hot and he had to abandon the chase when going after a Do335 very late in the war as he had the throttle firewalled but was unable to catch the German fighter.

It's also telling that many aircraft had pins or wires that had to be broken in order to advance the throttle through past the 100% mark into WEP and that breaking the pin or wire was an indication that the mechanics would be required to rebuild the engine when the aircraft landed.

When testing in IL-2 you should also note that the map you're on has an impact on how quickly the aircraft will overheat as well as altitude. Winter maps are cooler while summer maps are warm and tropical or desert maps are even warmer.

[WTE_Galway]

Originally Posted by palidian

The ME262 over heats at 100%, jet engines generally do not get hot (so to speak, at least not to start melting things.) due to there nature.

Well you do need to monitor engine gas temperature, that just goes without saying.



As far as the unreliability of the Jumo's in general one key factor is low quality steel ...

http://www.stormbirds.com/project/te...echnical_3.htm

JUMO The Junkers Jumo 004 is often remembered as a temperamental and failure-prone powerplant. Despite its advanced design, engine life was only between 10 and 25 hours, with the mean being at the lower end of this range. These failures were anticipated to some extent and the Me 262 was designed to permit extremely rapid engine changes.

Contrary to popular belief, the 004A was a fairly sound performer when premium steels were used, and early versions were known to achieve a 200-250 hour service life. However, the diversion of critical materials into U-boat production and other projects late in the war forced Junkers to produce the 004B model with only 1/3 of the high grade steel that had been used in the 004A. It was to be a disastrous concession for the Me 262.

The introduction of inferior metals compounded an already problematic situation with the turbine blade design. These blades were rigidly mounted, contributing to severe root stress relief problems. The weaker metals simply could not withstand this kind of abuse and regular compressor failures were an inevitable consequence.


Also remember that because the Jumo's are axial flow with FIXED geometry compressor blades they are also HIGHLY susceptible to compressor stall and surging with all the inherent problems (such as randomly shedding blades) that brings with it. These engines are nothing like the modern turboprops you may be used to working on or have studied.


Translated ME262 Pilots handbook:

http://www.zenoswarbirdvideos.com/Im...otHandbook.pdf

[palidian]

The manufacture sets the maximum throttle setting, that the engine can safely run. This setting is full military power, and in the game it should be 100%, anything past that point is WEP, and can cause damage to the engine, The p51 had to have an engine overhaul after 5 hours of WEP opperation. In game running at 100% should not overheat. I have never been able to go beyond 110%, some engines especially with nitrous oxide could go to 140%. Nitrous and water injection have a limited supply, I have never run out in game. Water injection will not cause overheating as it cools the combustion. The TA 152 had both nitrous and water injection, that option is not available. Some rework of the boost system need some rework.

For now I turn the engine overheating off, and wait for the next patch.