Compressible Navier-Stokes computations of multielement airfoil flows using multiblock grids

Numerical solutions of the compressible thin-layer Navier-Stokes equations are presented for high-lift multielement airfoil configurations. Multiblock grids are used, allowing straightforward implementation of an approximately factored implicit algorithm. Interfaces between blocks are treated by overlapping the grids and taking one layer of points from neighboring blocks. Turbulence is modeled using the Baldwin-Earth one-equation turbulence model. High-lift applications presented for comparison with wind tunnel data include: an NACA 4412 airfoil with NACA 4415 flap, a GA(W)-1 airfoil with a 29% chord flap at 30-deg flap angle and two gap settings, and a GA(W)-1 airfoil with 15% chord slat and 29% chord flap. Good agreement with experimental data is obtained for cases with fully attached flow or small regions of separated flow. For cases with extensive regions of flow separation, the thickness and extent of the separated regions are underpredicted.