Convergence Acceleration for Simulation of Steady-State Compressible Flows Using High-Order Schemes

The formulation of strategies for high-order discretization methods for compressible flow simulations is now to a certain extent understood, whereas the development of techniques for efficiently solving the resulting discrete equations has generally been lagging behind. Needs and constraints change greatly from case to case. In order to achieve the best-practice combination of all the ingredients composing the global strategy, target-specific tuning is required. We here take into consideration a Spectral Difference discretization for the Euler equations. We investigate convergence acceleration given by a full multigrid strategy implemented in conjunction with a hybrid multilevel relaxation technique. We also present the idea for a time-implicit relaxation technique, representing an intermediate solution between matrix-explicit and matrix-free techniques.