3-DIMENSIONAL UNSTRUCTURED ADAPTIVE MULTIGRID SCHEME FOR THE EULER EQUATIONS

This paper presents a solution adaptive multigrid scheme for the three -dimensional Euler equations. The procedure begins with an initial coa rse mesh and enriches this mesh by h-refinement in regions of high sol ution gradient. This adaptive procedure is used to generate the multig rid levels required by the solver. New boundary nodes are added in a w ay to reflect the underlying surface representation of the geometry. T he h-refinement procedure is extremely fast and results in a scheme Wh ere only a small percentage of the overall CPU time is spent in the me shing and refinement part of the algorithm. The multigrid now solver t ypically reduces the CPU time by an order of magnitude over the same c ase without multigrid. Initial mesh generation is achieved through the destructuring of a structured mesh or use of the advancing front meth od. The algorithm is demonstrated on a range of cases.