An anisotropic local grid refinement method for fluid flow simulation

Abstract

An anisotropic local grid refinement finite-difference method in a multigrid algorithm is introduced. This is implemented by using a new generalized interpolation and restriction operator. The code allows anisotropic local grid refinement in any direction or combination of any two directions. A multigrid algorithm is used to solve the discrete system of equations on both global and local grids. When the flow has different scales in different directions, isotropic refinement is not optimal. Anisotropic local grid refinements allows adaptation of the grid resolution to the physics of the problem. The method is demonstrated for a three-dimensional ventilation flow in the laminar and the turbulent regimes. The computed results are compared with the experimental results in the literature.