THREE DIMENSIONAL ANALYSIS OF A ROTOR IN FORWARD FLIGHT

The steady, incompressible laminar Navier-Stokes equations in Cartesian coordinates are solved for the flow field and performance characteristics of a helicopter rotor in forward flight. The rotor is modeled as a distribution of momentum sources, the strengths of which are determined from implicit functional relations involving the flow field properties, the rotor geometry and the aerodynamic characteristics of the blade cross-section. These strengths are calculated along with the rest of the flow field in an iterative manner using a finite-volume based primitive variable algorithm. No assumptions about the wake structure are made. Blade-loads are obtained for test cases and compared with experimental results. Solutions for the surrounding flow field representing both the near and far wake are also presented.