Dm. Tang et Eh. Dowell, DAMPING PREDICTION FOR A STALLED ROTOR IN FLAP-LAG WITH EXPERIMENTAL CORRELATION, Journal of the American Helicopter Society, 40(4), 1995, pp. 79-89
A direct numerical time-marching integration is used to compute the tr
ansient response (free oscillation) of the flap-lag motion of a rotor.
A time-domain quasilinear model identification technique is applied t
o identify the damping and frequency for the regressing mode, except f
or the chaotic lag response when stall occurs. Numerical examples and
correlation with previous experimental results are provided. It is fou
nd that the present theoretical method has improved the flap-lag stabi
lity analysis with respect to agreement with experiment.