Validation of Comprehensive Helicopter Aeroelastic Analysis with Experimental Data

The experimental data for a 4-bladed soft-inplane hingeless main rotor is used to validate a comprehensive aeroelastic analysis. A finite element model has been developed for the rotor blade which predicts rotating frequencies quite well, across a range of rotation speeds. The helicopter is trimmed and the predicted trim-control angles are found to be in the range of measured values for a variety of flight speeds. Power predictions over a range of forward speeds also compare well. Finally, the aeroelastic analysis is used to study the importance of aerodynamic models on the vibration prediction. Unsteady aerodynamics and free-wake models have been investigated