Turbulent flow simulations around a surface-mounted finite cylinder using an entropic multi-relaxation lattice Boltzmann method

摘要

Lattice-Boltzmann simulations of the turbulent flow around a surface-mounted circular cylinder at the height-to-diameter ratio of 1 are performed in order to assess the capability to capture the highly unsteady flow field. The Reynolds number based on the freestream velocity and cylinder diameter is 32 000 and the boundary layer thickness of the approach flow is equal to the cylinder height. We use two different formulations of the entropic multi-relaxation time model and the standard Bhatnagar-Gross-Krook model equipped with the Smagorinsky subgrid model. The unsteady flow behavior including the vortex structures are analyzed and both pressure coefficients and velocity profiles are evaluated. While the results of all Lattice-Boltzmann models are in good agreement with reference data, the entropic multi-relaxation time model based on central moments show the best predictive accuracy.