THE RESEARCH OF DISCONTINUOUS GALERKIN P-MULTIGRID SOLVER

摘要

With unstructed elements as basic element andrnnormal orthogonal basis as test functions, a pmultigridrnsolution strategy is developed forrndiscontinuous Galerkin discretizations of therntwo-dimensional Euler equations. This solver isrnused to compute transonic flow over the airfoilrnNACA0012 and RAE2822. The numerical flux ofrnEuler equations are calculated by using Roernscheme. Along the direction of time, an explicitrnRunge-Kutta scheme is applied for the p levelrn(i.e. the higher order accuracy), while anrnimplicit scheme is applied for the p-1 level(i.e.rnthe lower order accuracy). The performance ofrnthe solver in term of convergence efficiency isrninvestigated. Compared with the single grid (SG)rnsolver, the p-multigrid (MG) solver is found torndeliver nearly optimal convergence rate. At last,rnsome reason of the acceleration about it isrnanalyzed.