Parallel Poisson Solver for Revolved Unstructured Grids. DNS of the Flow Around a Sphere at Re = 3700

Abstract

In this paper a parallel direct Poisson solver for DNS simulation of turbulent flows in domains of revolution using unstructured meshes is presented. It is based on a Fourier diagonalization in the azimuthal direction and a Schur Complement based decomposition in the other two directions. Numerical experiments carried out on the IBM MareNostrum supercomputer, are presented in order to test the robustness and efficiency of the algorithm up to 640 CPU. This solver is being used for a DNS of a turbulent flow around a sphere. The results of the initial case of study at Re = 3700 are presented.