Surrogate Based Optimization of Helicopter Rotor Blades for Vibration Reduction in Forward Flight

The effectiveness of surrogate modeling of helicopter vibrations, and the use of the surrogates for optimization of helicopter vibration are studied. The accuracies of kriging, radial basis function interpolation, and polynomial regression surrogates are compared. In addition, the surrogates for the vibratory hub shears and moments are used to generate an objective function which is employed in an optimization study. The design variables consist of the cross-sectional dimensions of the structural member of the blade and the non-structural masses. The optimized blade is compared with a baseline rotor blade which resembles an MBB BO-105 blade. The results indicate that: (a) the kriging surrogates are the best for approximating vibratory hub loads over the entire design space and (b) and the surrogates can be used effectively in helicopter rotor vibration reduction studies.