2020/02/28 by Ali Kashefi, Kashefi, Ali
Engineering · #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Fluid Dynamics and Turbulent Flows #Fluid Dynamics and Vibration Analysis #Lattice Boltzmann Simulation Studies
paper · pdf · doi:10.48550/arxiv.2003.00082
openalex publication_date 2020/02/28 · openalex created_date 2022/07/26 · openalex updated_date 2026/07/28
Coarse grid projection (CGP) is a multiresolution technique for accelerating\nnumerical calculations associated with a set of nonlinear evolutionary\nequations along with the stiff Poisson equations. In this article we use CGP\nfor the first time to speed up incompressible magnetohydrodynamics (MHD) flow\nsimulations. Accordingly, we solve the nonlinear advection-diffusion equation\non a fine mesh, while we execute the electric potential Poisson equation on the\ncorresponding coarsened mesh. Mapping operators connect two grids together. A\npressure correction scheme is used to enforce the incompressibility constrain.\nThe study of incompressible flow past a circular cylinder in the presence of\nLorentz force is selected as a benchmark problem with a fixed Reynolds number\nbut various Stuart numbers. We consider two different situations. First, we\nonly apply CGP to the electric potential Poisson equation. Second, we apply CGP\nto the pressure Poisson equation as well. The maximum speedup factors achieved\nhere are approximately 3 and 23 respectively for the first and second\nsituations. For the both situations we examine the accuracy of velocity and\nvorticity fields as well as the lift and drag coefficients. In general, the\nresults obtained by CGP are in an excellent to reasonable range of accuracy and\nare significantly consistently more accurate than when we use coarse grids for\nthe discretization of both the advection-diffusion and electric potential\nPoisson equations.\n