Solutions Of The Navier-Stokes Equations For The Flow About A Rotor Blade

A numerical solution procedure for solving the three-dimensional unsteady Navier-Stokes equations is described and applied to the flow over a helicopter rotor blade. This procedure solves the Navier-Stokes equations in a time-accurate manner. Steady solutions are obtained by marching through time and asymptotically converging to steady state. The procedure is a hybrid ADI scheme that has previously been applied to the solution of the Euler equations for fixed and rotary wings. The present hybrid procedure results in an efficient method, capable of handling relatively large time steps. The influence of the rotor wake is included by the transpiration-velocity technique. For turbulence, a two-layer algebraic model is used. The method is applied to the subsonic flow of a hovering rotor blade with encouraging results. Unsteady calculations for a high-speed nonlifting rotor have also been made and compared with experimental data and Euler results.