Computational Investigation of Advanced Hub Fairing Configurations to Reduce Helicopter Drag

Kurzfassung

The paper reports investigation of the aerodynamic performance of different hub fairing shapes and compares them to the baseline hub. The investigation relies on stationary RANS simulation of air flow past the GRC common platform fuselage and a generic main rotor hub in cruise flight at Mach number equal to 0.204, and -2.5o pitch angle. Modular grids were generated around two fuselage configurations and three main rotor hub shapes. Four different combinations of fuselage and rotor hub grids were generated using Chimera overlapping grid technique. The DLR unstructured RANS solver TAU was applied to predict the aerodynamic loads acting on the different computational configurations. The results revealed significant contribution of blade attachments and stubs to hub drag. An overall drag reduction of 17-19% could be obtained by proper optimization of the fairing, blade attachments and stubs.