NUMERICAL BEHAVIOR OF UNSTEADY WAVES

Two unsteady Euler solvers using high-order upwind finite volume metho ds are presented and compared. The first uses the Van Leer nux vector splitting on structured moving grids and includes compatibility relati ons to treat boundary conditions. The second is based on Roe's approxi mate Riemann solver on fixed unstructured, finite element type meshes and uses a standard explicit boundary treatment. Results for one- and two-dimensional strong wave propagation and interaction show very good agreement between the two approaches and reference solutions, despite the use of different flux evaluations and integration cells. The two schemes even exhibit the same numerical sensitivity of wave propagatio n to mesh orientation. However, the simulation of the shock wave refle ction from a wall reveals some flaws in the second solver's slip wall treatment which are avoided by the compatibility relations used in the first method.