Damping prediction for hingeless rotor aeroelastic stability with experimental correlation

A numerical simulation technique is applied to determine the transient response of a hingeless rotor model and predict the lag damping for correlation with experimental results from a wind-tunnel test. Numerical investigations indicate that the present theoretical/numerical method improves somewhat the correlation of the theoretical and experimental results over earlier eigenvalue, perturbation analyses. For a shaft angle of alpha(s) = 0 and -3 deg, the correlation still is not acceptable for the advance ratios, mu > 0 2. In addition to a steady inflow model, a 3 x 3 dynamic inflow model is also used in the present method. The results with this dynamic inflow model show some improvement relative to the experimental data, as compared to the uniform inflow model. For further improvement of the correlation with the experimental data, a highly efficient, accurate aerodynamic model suitable for the rotor blade aeroelastic stability analysis is required.