A method of computing the aerodynamic interactions of a rotor-fuselage configuration in forward flight

A method is derived for determining the combined aerodynamic effects of a lifting rotor system in the presence of a non-lifting fuselage. The method allows for the full aerodynamic interaction of the lifting rotor blades, the non-lifting body, and the wake sheets trailing from the rotor blades. The wake sheets are allowed to convect with the local induced velocities, creating a distorted wake geometry.;The method develops the trailing wake system by time marching from an initial impulsive start. Azimuthal dependent velocities and pressures are predicted. The predictions are compared with other analysis and experimental data.;The method models the fluid viscous effects by confining these effects to regions adjacent to the bodies and to the wake sheet. The flow outside these regions is modelled as an incompressible potential. A vortex lattice system consisting of discrete vortex filaments is used to represent the lifting rotor system and rotor wake. The non-lifting fuselage is modelled with constant strength source panels.