Wall-resolved large-eddy simulation of flow past a circular cylinder*

Wall-resolved large-eddy simulations (LES) about a smooth-walled circular cylinder are described over a range of Reynolds number from $Re_D = 3.9\times 10^3$ (subcritical) to above the drag crisis, $Re_D=8.5\times 10^5$ (supercritical), where $D$ is the cylinder diameter. The span-wise domain is $3\,D$ for $Re_D \le 10^5$ and $D$ otherwise. The numerical method is a fourth-order finite-difference discretization on a standard curvilinear O-grid. The stretched-vortex sub-grid scale model is used in the whole domain, including regions of large-scale separated flow. For $Re_D \le10^5$, calculations of the skin-friction coefficient versus polar angle $\theta$ along the cylinder surface and its dependence on $Re_D$ are well captured in comparison with experimental data. Proper separation behavior is observed. For high $Re_D$, a fine mesh $8192\times 1024\times 256$ is used. It is found that a blowing/suction-type perturbation of the wall-normal velocity along a span-wise strip, with angular position at $\theta =50-60^o$, is then required in order to produce flow separation in accordance with experiment at Reynolds numbers in the drag-crisis regime. Results presented will focus on the skin-friction behavior and details of flow separation.