Advection-diffusion lattice Boltzmann scheme for hierarchical grids

In this paper we describe an extension of a recently developed lattice Boltzmann method for solving the advection-diffusion equation. Our proposed approach allows to couple grids of different grid resolutions and includes a staggered timestepping scheme, interpolations in space and time and finally a scaling step ensuring the continuity of the desired macroscopic quantities across the grid interface. After validating the basic lattice Boltzmann method on a uniform grid by a convergence study of analytic problems we demonstrate the consistency of our approach by solving benchmark problems and comparing results on uniform grids and multiply locally refined grids. (c) 2007 Elsevier Ltd. All rights reserved.