Unsteady Overset Simulation of Rotor-Airframe Interaction

Inviscid, three-dimensional, unsteady flow computational results for the aerodynamic interaction between a rotor and a hemispherical-cylinder airfra me are presented. A multiblock strategy is used, with separate grids for the fuselage and the rotor blades. An overset grid methodology is used to communicate the flow information between the grids. In each grid a second-order temporally accurate,fifth-order spatially accurate, implicit nite volume scheme is employed to solve the Euler equations. The vortical wake generated by the blade is captured from first principles. The vorticity patterns that impinge on the airframe are analyzed, and the surface-pressure distributions on the airframe are compared with experimental values.