Lattice-Boltzmann LES of Vortex Shedding in the Wake of a Square Cylinder.

The success in the use of lattice-Boltzmann methods for the simulation of laminar .ows has prompted the interest in extending the technique for the simulation of turbulent flows. In this paper, a square cylinder at Re = 21400 is used to investigate the suitability of lattice-Boltzmann methods to solve turbulent unsteady problems with open boundary conditions. Numerical simulations are performed with a single-relaxation-time lattice-Boltzmann method and with a large-eddy simulation turbulence model. These simulations present several not-fully-resolved issues for lattice-Boltzmann methods, which are briefly discussed in this paper. Specifically, we propose a filtered-density open-boundary condition for fluid-flow simulations with the lattice-Boltzmann equation. This filter modification of inflow boundary condition is shown to improve simulations of unsteady flows at high Reynolds numbers, in terms of calculation stability and speed, and quality of the results. [ABSTRACT FROM AUTHOR]