Optimal Design and Acoustic Assessment of Swept-tip Helicopter Rotor Blades

"An optimization procedure for the design of helicopter rotors that generate reduced vibratory hub loads is presented. Blade shape and structural properties are the parameters examined by a binary genetic optimization algorithm, under aeroelastic stability constraint. The optimization process applies a rotor aeroelastic tool based on a nonlinear, beam-like model, suited for the analysis of blades with curved elastic axis. (sweep\/anhedral tip angles included). Further, the aeroacoustic assessment of the identified optimal rotor. configuration is accomplished in order to examine its performance in terms of noise field emitted. Numerical. results are presented to demonstrate the capability of the proposed approach to identify low vibratory hub. loads rotor blades, as well as, to assess the robustness of solution at off-design operating conditions.. "