PPRuNe Forums - View Single Post - Angle of Attack rule of thumb
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Old 31st Jan 2003, 14:38
  #11 (permalink)  
DustDevil
 
Join Date: Nov 2001
Location: Toulouse, France
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Mad Scientist,
Entirely agree with your explanations. I didn't mention above the important step which have to be done at each updates :
- project plane-relative velocity in terrestrial reference system
- updating plane angular positions.
and on the next step,
- project terrestrial-relative speed on the new plane axis reference,
- on this new reference, compute accelerations and speed
- project plane-relative velocity in terrestrial reference system
etc... etc...
So i use terrestrial system as an intermediary reference system beetween each plane axis change.And this steps are necessary to avoid stability problems you described.

Concerning aerodynamic forces computations : i have used simple equations 0.5*rho*V2*S*C on different parts of my plane, computing local airspeed and angle of attack for each parts. It seem to work well in low speed. But there are limitations such as :
- compressibility effect, when mach number become high
- interferences of airflow beetween parts.
- probably others that i didn't think about

Does someone know others way to do that, or correction for this ?
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