NUMERICAL-SOLUTION FOR AIRFOILS NEAR STALL IN OPTIMIZED BOUNDARY-FITTED CURVILINEAR COORDINATES

Boundary-fitted curvilinear coordinate systems are optimized for viscous flows about arbitrary airfoils at angles of attack such that boundary-layer-dependent grid systems for high Reynolds numbers are generated efficiently. The grid systems are utilized in implicit finite-difference solutions. Solution of a one-dimensional model equation is compared with the theoretical solution. The unsteady Navier-Stokes equations are solved for the incompressible flow around a cylinder and around NACA airfoils approaching stall. The predicted flows around a NACA 6412 airfoil near stall at Reynolds numbers of 4 × 104 and 2 × 105 are compared with the experimental observations obtained in a smoke tunnel. © 1979 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.