3-DIMENSIONAL ANALYSIS OF A ROTOR IN FORWARD FLIGHT

The steady, incompressible laminar Navier-Stokes equations in Cartesia n coordinates are solved for the flow field and performance characteri stics of a helicopter rotor in forward flight. The rotor is modeled as a distribution of momentum sources, the strengths of which are determ ined from implicit functional relations involving the flow field prope rties, the rotor geometry and the aerodynamic characteristics of the b lade 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. With no a priori knowledge, the wake is solved for in a time-averaged sense. Blade-loads are obtained for test cases and compared with experimental results. Solutions for the surro unding flow field representing both the near and far wake are also pre sented.