Comparison of calculated vibratory rotor hub loads with experimental data

Vibratory hub loads predicted by a comprehensive aeroelastic analysis are compared with wind tunnel test data. The analysis is based on a finite element method in space and time. Rotor loads are calculated using a force summation method, The test data include several model rotor configurations with different mass and stiffness distributions along the blade. The influences of unsteady aerodynamics and nonuniform inflow on variation of rotor loads prediction are investigated. Effects of blade inertial and stiffness properties on the rotor hub loads are also investigated. The overall trends in vibratory hub loads due to changes in mass and stiffness properties are satisfactorily captured by the analysis, However, the magnitudes of the prediction are generally low by as much as 50 percent in some cases.