Comprehensive Aeromechanics Predictions on Air and Structural Loads of HART I Rotor

The aeromechanics predictions of HART I rotor obtained using a computational structural dynamics (CSD) code are evaluated against the wind tunnel test data. The flight regimes include low speed descending flight at an advance ratio of μ = 0.151 and cruise condition at μ = 0.229. A lifting-line based unsteady airfoil theory with C81 table look-up is used to calculate the aerodynamic loads acting on the blade. Either rolled-up free wake or multiple-trailer wake with consolidation (MTC) model is employed for the free vortex wake representation. The measured blade properties accomplished recently are used to analyze the rotor for the up-to-date computations. The comparison results on airloads and structural loads of the rotor show good agreements for descent flight and fair for cruise flight condition. It is observed that MTC model generally improves the correlation against the measured data. The structural loads predictions for all measurement locations of HART I rotor are investigated. The dominant harmonic response of the structural loads is clearly captured with MTC model.