PBL
Maybe because it does?
Sorry PBL - Rivet-gun is correct - it doesn't.
CAS relates to EAS; the speed of sound expressed in EAS is independent of temperature as discussed on another thread. Ergo Mach Number as a ratio between EAS/CAS and the speed of sound is also independent of temperature.
Selfin
What I do not understand is why an incompressible solution is used when dealing with ‘speeds’ above Mach 0.3. The idea of basing any calculations on an incompressible formula in the transonic regime is simply baffling to me.
I see where you are coming from, but the answer is probably historic. There is an ENORMOUS amount of data kicking about which has been calculated using dynamic pressure as usually defined and to shift now would make that useless. Presumably if one changed to your 'impact pressure' as a basis for reducing measured data one would hope to eliminate compressibiity effects from the coefficients i.e. they might then be independent of Mach No, but looking at the other curves in Hazelnuts 39's chart I don't think that would be so, so to paraphrase his remark re change from CAS to EAS in an earlier posting - what would be the point of changing now to impact pressure rather than dynamic pressure?
Hazelnuts 39
Your graphs of Cl/Clo look a lot like those of a large transport aircraft with which I am very familiar, and seeing your location is France (mostly) I am wondering if we have worked together????