VISCOUS-INVISCID INTERACTION USING THE NAVIER-STOKES EQUATIONS

A numerical model for the calculation of incompressible viscous flows past airfoils and wings has been developed. The approach is based on a strong viscous-inviscid coupling of a boundary element method with th e Navier-Stokes equations in vorticity-stream function formulation, A semiadaptive or fully adaptive grid is used. The interaction is achiev ed by iterative updating of the boundary conditions, through the wall transpiration concept. The Navier-Stokes equations are discretized on a semistaggered grid. Space-marching integration is performed starting from the stagnation streamline on two independent blocks. Results are presented for two different airfoils. Comparisons with experimental r esults and other calculations show that the present algorithm performs well for flows at angles of attack up to maximum lift and mild separa tions.