PPRuNe Forums - View Single Post - Lift limit - Reducing AoA with an increase in CAS?
Old 7th November 2011 | 19:32
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henra
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From: PLanet Earth
Originally Posted by bunghole
G'day BOAC,

From 0.2 to 0.6 Mach you can ignore compressibility. The graph distinctly shows a decrease in alpha on the lift limit (from about 12 to 8 alpha over this speed regime)
Interesting.
Conventional wisdom has it that compressibility effects aside there is a slight positive dependency of AoAmax on Reynolds number i.e. velocity.
Meaning that at higher speeds AoA max should be slightly higher than at lower speeds. (Background: IIRC it is due to earlier Boundary layer separation at higher speeds causing the stream to stay semi-attached longer).

The fact that in this case it is the opposite seems to point towards compressibility effects.
What type of aircraft are we talking about?

regards,
henra
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