PARALLEL COMPUTATION OF THE 2-D NAVIER-STOKES FLOWFIELD OF A PITCHINGAIRFOIL

An unsteady, compressible, two dimensional Navier-Stokes solver has be en developed for the Connection Machine (CM-2 and CM-5). The solver ha s been applied to the computations of subsonic viscous flow past a pit ching airfoil at Re-c = 10(4), (based on airfoil chord length) M(infin ity) = 0.2, non-dimensional pitching rate Omega(o)(+) = 0.2 and 0.4. T he algorithm for solving the Navier-Stokes equations is based on an un structured grid of triangles. Roe's flux difference split method is em ployed for the inviscid fluxes. A discrete representation of Gauss' th eorem is used for the viscous fluxes and heat transfer. A four stage m odified Runge-Kutta algorithm is employed for the temporal integration . The algorithm is second order accurate in space and time. The implem entation of the algorithm on the Connection Machine and the investigat ion of the incipient boundary layer separation for a pitching airfoil are presented. The investigation of the effect of pitching rate on inc ipient boundary layer separation for a pitching airfoil shows that inc reasing Omega(o)(+) delays the formation of the three recirculating re gions near the leading edge and results in higher values of the lift a nd drag coefficients.