(298f) Practical Large Eddy Simulation: Extension to Variable Mesh Systems

A lattice-Boltzmann approach for performing large eddy simulations (LES) across domains with spatially varying lattice resolutions is presented. This approach uses nested sub-volumes to create high-resolution sub-domains about momentum sources inside closed tanks. We begin by discussing the macroscopic and microscopic communication required to link lattices with disparate resolutions. Next, we discuss the computational overhead associated with nested sub-volumes, as opposed to conventional approaches using a uniform lattice. For systems with large tank-to-impeller diameter ratio, the variable mesh approach is shown to be order-of-magnitude faster. We conclude with a set of validation exercises, specific to mixing and agitator performance.