Finite Difference Modeling of Rotor Flows Including Wake Effects

: This paper gives a brief consideration of rotary wing finite difference methods. The main concern is the specification of boundary conditions to properly account for the effect of the wake on the blade. Examples are given of an approach where wake effects are introduced by specifying an equivalent angle of attack. An alternate approach is also given where discrete vortices are introduced into the finite difference grid. The resulting computations of hovering and high advance-ratio cases compare well with experiment. Some consideration is also given to the modeling of low-to-moderate advance-ratio flows. (Author)