HELICOPTER FUSELAGE AERODYNAMICS UNDER A ROTOR BY NAVIER-STOKES SIMULATION

An incompressible Navier-Stokes code was modified to model the effects of a helicopter rotor in forward flight on the viscous aerodynamics o f the fuselage. The rotor was treated in a manner similar to an actuat or disk, with the thrust being modelled as a jump in pressure across t he disk. Unlike an actuator disk, the pressure jump was allowed to var y with radial and azimuthal locations on the disk and was computed fro m a fully coupled blade element model. Swirl velocities were implement ed by adding a jump in tangential velocity across the disk surface. Ch imera grids were used to allow more complex configurations to be model led. Calculations were made for an isolated rotor as well as for a rot or/fuselage geometry and compared with experimental inflow velocity da ta and experimental fuselage surface pressure data. The time-averaged effect of the rotor on the fuselage as well as the time averaged effec t of the fuselage on the rotor are shown.