Enhanced Rotorcraft Aerodynamic Modules to Support Flight Testing

Progress has been made in developing high fidelity rotorcraft simulation models in order to adequately predict rotorcraft performance, stability, and loads in support of design, operation, and flight testing. Limitations, however, exist in several essential aspects of modeling rotor aerodynamics including blade stall, rotor tip effects, rotor downwash, rotor/airframe interference, and rotor aeroelastic interaction. We propose to: (1) enhance blade dynamic stall modeling to improve the prediction of 3D stall delay and accuracy of blade drag and pitch moment; (2) enhance blade tip modeling to consider the 3D blade tip effect; (3) enhance high rate of descent modeling by including the effects of unsteady variation of the vortex ring state; (4) enhance rotor wake and aerodynamic interference modeling by allowing for the effects of high blade twist and inclusion of fuselage interference on the rotor; (5) enhance rotor aeroelastic modeling by developing a coupled airframe/rotor and coupled FLIGHTLAB/CFD solution for the aeroelastic blade loads calculation.