Innovative Systems for Reduction of Rotorcraft Hub Drag

This technology program investigates methods to reduce the aerodynamic drag of the helicopter rotor hub and blade shanks, including investigation of the hub/pylon relationship and its contribution to the flat plate drag of the hub. Examination of both active and passive technologies which can be applied is an integral part of the study effort. The H-60 is selected as the baseline air vehicle for the study. A baseline weight and drag level will be established and a set of design criteria developed to ensure that the drag reduction approach will not compromise the basic mission capability and maintainability of the aircraft. A detailed geometric model of the hub and shank areas will be developed, and a multi-case CFD analysis of both the baseline and advanced hub designs will be conducted. A study matrix that cycles each design ap-proach through varying dynamic pressure levels, angles of attack, and separation points will be con-ducted, leading to the selection of alternative solutions for a final recommendation for the technology initiative to be pursued in Phase II. During the Option Phase, planning for Phase II full-scale fabrication and testing of the reconfigured hub will be conducted.