Numerical simulation of the flow around a circular cylinder at high Reynolds number

Abstract

This chapter explores the viability and accuracy of large eddy simulation (LES) with wall modeling for high Reynolds number complex turbulent flows by considering the flow around a circular cylinder in a super-critical regime. A simple wall stress model is employed to provide the approximate boundary conditions to the LES. This model alleviates the grid resolution requirements. The results so obtained are then compared with those obtained from steady and unsteady Reynolds-Averaged Navier-Stokes (RANS) and the available experimental data. The LES simulations are shown to be considerably more accurate than the RANS results. They correctly capture the delayed boundary layer separation and reduced drag coefficients consistent with experimental measurements after the drag crisis. It is observed that the mean pressure distribution is predicted correctly. However, the Reynolds number dependence is not predicted accurately because of the limited grid resolution. It is noted that a more systematic investigation is needed to separate the grid resolution and wall modeling effects, and to fully validate the numerical methodology for this challenging flow.