THREE-DIMENSIONAL UNSTRUCTURED GRID GENERATION FOR FINITE-VOLUME SOLUTION OF EULER EQUATIONS

摘要

To solve the Euler equations on a threedimensionalrnunstructured grid, an efficientrnprocedure for generation of relatively highrnquality elements is presented. The basic steps ofrnthis method, which is essentially based onrnDelaunay’s triangulation, is consisted ofrngenerating surface points, initial tessellation,rnpoint distribution function interpolation,rninternal node generation and updaterntriangulation. Special treatments forrnsurmounting degenerate cases are consideredrnwithin the algorithm. Validation and reliabilityrnof algorithm are checked by different examples.rnAn upwind scheme is used to solve Eulerrnequations on these unstructured grids forrnsteady-state problems. Spatial discritization isrnaccomplished by a cell-centered finite-volumernformulation using flux-difference splittingrnmethod of Roe. Solution is advanced in time byrna simple explicit scheme. Local time stepping isrnused to accelerate convergence to the steadyrnstate. Some application cases are treated to testrnthe method.