Damping prediction for a stalled rotor in flap-lag with experimental correlation
A direct numerical time-marching integration is used to compute the transient response (free oscillation) of the flap-lag motion of a rotor. A time-domain quasilinear model identification technique is applied to identify the damping and frequency for the regressing mode, except for the chaotic lag response when stall occurs. Numerical examples and correlation with previous experimental results are provided. It is found that the present theoretical method has improved the flap-lag stability analysis with respect to agreement with experiment.