EFFECTS OF ROTOR MODEL DEGRADATION ON THE ACCURACY OF ROTORCRAFT REAL-TIME SIMULATION

摘要

A study was conducted to determine the effects of degrading a rotating blade element rotor mathematical model to meet various real-time simulation requirements of rotorcraft. Three methods of degradation were studied:reduction of number of blades, reduction of number of blade segments, and increasing the integration inter¬val, which has the corresponding effect of increasing blade azimuthal advance angle. The three degradation methods were studied through static trim comparisons, total rotor force and moment comparisons, single blade force and moment comparisons over one complete revolution, and total vehicle dynamic response comparisons. Recommen¬dations are made concerning model degradation which should serve as a guide for future users of this mathematical model, and in general, they are in order of mini¬mum impact on model validity:(1) reduction of number of blade segments, (2) reduction of number of blades, and (3) increase of integration interval and azimuthal advance angle. Extreme limits are specified beyond which the rotating blade ele¬ment rotor mathematical model should not be used.