Large Eddy Simulation Using an Unstructured Mesh Based Finite-Volume Solver

Abstract

This paper concerns development of a large eddy simulation (LES) capability for a finite-volume solver which permits use of unstrcutured meshes. The solver employs a cell-centered scheme based on a multi-dimensional linear reconstruction scheme. Both convection and diffusion terms are discretized using central-differencing scheme. A three-level, second-order scheme is used for temporal discretization. For subgrid-scale turbulence modeling, the dynamic Smagorinsky’s model and the dynamic turbulent kinetic energy transport model were implemented. A noble test-filter was designed which is applicable to unstructured meshes of arbitrary cell topology. The dynamic procedure is local, which renders itself applicable to three-dimensional flows without any homogenous directions. The wall boundary condition is effected using a wall-function approach which applies appropriate wall-laws depending on the near-wall mesh resolution. The LES capability is validated for several wall-bounded flows including a fully-developed channel flow, a cavity flow, flow around a sqaure cylinder, flow around a sphere. The results are in good agreements with the data and the numerical results reported by others.