Steady and Unsteady Euler Simulation Using Different Schemes on Structured and Unstructured Grids

Two methods for computing the flow around moving objects by the unsteady Euler gas dynamics are developed and compared. The first is based on a finite volume space discretization, for structured grids, using the second order van Leer flux vector splitting. The second one, aimed at unstructured triangular grids, employs a cell vertex finite volume method, corresponding to a central difference space discretization, augmented by second and fourth order artificial dissipation. Since flow around moving objects is considered, the equations are applied to moving grids. The equations are advanced in time by a Newton/Gauss-Seidel iterative procedure allowing large enough time steps motivated by the physical scales of interest. The solvers have been applied to both steady and unsteady flow cases and results are compared with experimental data. A special application is the coupling with a simple mechanical system consisting of a rigid wing profile, allowed to perform vertical translation and rota..