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Old 05-26-2013, 10:52 AM
jf1981 jf1981 is offline
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Quote:
Originally Posted by Charly_Owl View Post
1) About Mixture
How does increasing or decreasing the mixture affect my in-flight performances? Is it controlling the fuel flow so that engine's performance is better and generates more thrust? I'd like to have some explanations so I can understand how to use it efficiently in-flight, and for which cases I should use high % mixture vs low % mixture.
Hi,
In short, too rich mixture does not generate more power however send fuel that will not be burnt and hence wasted. On the other side, it will allow engine to run a little bit cooler.

In Cliffs of Dover, you will notice lower fuel consumption when leaning the mixture above 10/15 kft (> 3000 meters). Leaning the mixture in thin air allows the correct fuel/air mixture to be maintained however stay rich at full power because you may damage the engine particularly in a dive. It depends if CoD takes care of this possible engine failure case.

Quote:
3) About propeller pitch
I know they affect the thrust generated. But why would you want to increase or decrease prop pitch during a dogfight as I've seen in many youtube videos? I'm curious about the reasons behind it.
An engine can run with higher torque at lower rpm which would result in the same as higher rpm with less throttle (or less torque) => in both cases same power. However if you can run lower in rpm you should have a better efficiency and so less fuel burnt, less noise also, one more point that CoD does'nt take care of, the engine lasts longer (better for maintenance).

In short for CoD : if you have a constant speed propeller (like Spitfire II for example), you better run at higher rpm during dogfight and take off, lower during cruise.
If you have a constant pitch propeller (like some BF 109) then also take care not to run the engine too high in rpm for example in a dive you should coarse the pitch or reduce throttle, because it will not take care of it, the pilot has to. If not the engine at overspeed may be failed !
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