THE RESEARCH OF DISCONTINUOUS GALERKIN P-MULTIGRID SOLVER

摘要

With unstructed elements as basic element and normal orthogonal basis as test functions, a pmultigrid solution strategy is developed for discontinuous Galerkin discretizations of the two-dimensional Euler equations. This solver is used to compute transonic flow over the airfoil NACA0012 and RAE2822. The numerical flux of Euler equations are calculated by using Roe scheme. Along the direction of time, an explicit Runge-Kutta scheme is applied for the p level (i.e. the higher order accuracy), while an implicit scheme is applied for the p-1 level(i.e. the lower order accuracy). The performance of the solver in term of convergence efficiency is investigated. Compared with the single grid (SG) solver, the p-multigrid (MG) solver is found to deliver nearly optimal convergence rate. At last, some reason of the acceleration about it is analyzed.