Exploring for aerodynamic and structural design constraints in the multi-objective rotor blade airfoil optimization framework

Abstract

A rotor blade design optimization framework has been developed by integrating the Dakota, C81Gen, ParFoil, and RCAS software packages in Galaxy. Parameterizing the airfoils using ParFoil was performed prior to the rotor blade optimization. Using Dakota’s Multi Objective Genetic Algorithm (MOGA), global design optimization was successfully carried out for the UH-60A rotor blade. It shows a 12.2% reduction at ? = 0.4, a 9.4% reduction at ? = 0.35 and a 3.0% reduction in hover. The expansion of flight envelope is also explored by examining the aerodynamic responses of the optimized rotor under high load conditions. It is found that the optimized rotor designed under the normal cruise condition fails to meet performance expectations when it is exposed to high load conditions where rotor encounters the retreating blade stall. Realistic rotor blade design therefore needs to include a high load condition so that a rotor can perform well at high thrust and high speed.