Lattice Boltzmann Simulations with Locally Refined Meshes

The present study focuses on the implementation of a local grid-refinement technique into a single-relaxation-time Lattice-Boltzmann Method (LBM). To demonstrate the performance of this method, the flow past a circular cylinder at Reynolds numbers ReD = 20, ReD = 40, and ReD = 100 and the flow past a sphere at ReD = 100, ReD = 300, ReD = 3700, and ReD = 10 4 are simulated. At turbulent flows the large-eddy simulation concept is used. The LBM plus local grid refinement yields accurate temporal and spatial results and increases the computational efficiency due to a drastic reduction of the cell number. In two dimensions the computational effort is reduced by a factor of more than 50 and in three dimensions a reduction by a factor above 400 is achieved.