Improving the Efficiency of Explicit Schemes for 3D Inviscid Compressible Flows with Moving Boundaries on Unstructured Meshes

摘要

An adaptive finite element method for the simulation of transient 3D compressible inviscid flow is presented. The method is based upon an arbitrary Lagrangian-Eulerian formulation implemented on unstructured tetrahedral meshes. The addition of a mesh adaptivity procedure allows forthe simulation of transient problems involving moving boundaries. The solution is advanced in time via explicit method and, to improve efficiency three methods of time stepping schemes are investigated. The first tw o methods involvea decomposition of the domain in to regions, according to a local allow able time step size.The third method involves the use of an implicit formulation, with the solution obtained by an explicit multigrid procedure. The improvements in computational efficiency that can be achieved are demonstrated by presenting results achieved for simulations involving an oscillating wing.