Parallel direct Poisson solver for DNS of complex turbulent flows using Unstructured Meshes
In this paper a parallel direct Poisson solver for DNS simulation of turbulent flows statistically homogeneous in one spatial direction is presented. It is based on a Fourier diagonalization and a Schur decomposition on the spanwise and streamwise directions respectively. Numerical experiments carried out in order to test the robustness and efficiency of the algorithm are presented. This solver is being used for a DNS of a turbulent flow around a circular cylinder at Re = 1 ×104, the size of the required mesh is about 104 M elements and the discrete Poisson equation derived is solved in less than one second of CPU time using 720 CPUs of Marenostrum supercomputer.
Key wordsparallel Poisson solver Schur decomposition FFT DNS unstructured meshes
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