Useful viscous flow solver for control surface deflection using unstructured mixed element grids

The advancing-layer method is modified to generate high quality mixed (prismatic/pyramid/tetrahedral) element unstructured grids in boundary-layer region and advancing-front method is used to construct isotropic tetrahedral grids in the residual flow region. Three-dimensional Navier-Stokes equations are solved by using a cell-centered finite-volume method with central difference scheme and Spalart-Allmaras one-equation turbulence model. Time is advanced by an implicit Gauss-Seidel relaxation procedure, which is constructed by using the first-order linearizing of flux vector and the maximal eigenvalue splitting of flux Jacobi matrix. The simulation results of complex viscous flow around a 3D model wing with control surface are presented. The influences of attack angle, control surface deflection angle and Mach number on the flow separation are systematically investigated. Moreover, the comparison between the moments of gamel obtained by numerical simulations with those obtained by wind tunnel tests is presented; it should be pointed out that test data for one type of balance show noticeable difference from those for another type of balance. The computed results agree fairly well with the experimental data, which indicates that the viscous flow solver of this paper is useful in simulating the massively separated flows around 3D wing with deflection of control surface.