A finite volume solver for viscous turbulent flows on mixed element unstructured meshes

grantor: University of TorontoA finite-volume solver for the two-dimensional compressible Navier-Stokes equations on unstructured grids is presented. The solver is formulated to operate on any type of grid elements, including triangular and quadrilateral elements. The calculation of viscous fluxes are detailed, and the implementation of the Spalart-Allmaras turbulence model is described. The solver uses a centroid-median dual for the calculation of fluxes, with scalar numerical dissipation, and a Runge-Kutta time marching method. Residual smoothing, local time stepping and agglomeration multigrid are used to accelerate convergence. A wide variety of test cases are presented, including laminar flows, low and high Mach number turbulent flows, as well as two high-lift cases involving a three-element airfoil. Good performance is shown in all test cases, and quadrilateral cells are found to be considerably more accurate than triangular cells for some test cases. Mixed grids, with quadrilaterals in the boundary layer and triangles in the far field, are successfully used.M.Sc