LES of Flow Past a Circular Cylinder With Roughened Surface

The present work concerns large eddy simulation (LES) of flow past smooth and roughened circular cylinder at Reynolds numbers in the subcritical, critical, and supercritical regimes. The cylinder surface is either entirely or partially roughened by irregular distributed roughness. The statistics obtained from the actual roughness samples are used to numerically generate the roughness height distribution on the cylinder surface. Part of the roughness height variations on the surface can be resolved by the LES grid, the contribution from the unresolved part of the surface roughness is modeled by a dynamic sub-grid-scale (SGS) surface roughness model developed by Anderson & Meneveau. Similar to the dynamic Smagorinsky SGS model, the model parameter is determined dynamically using a consistency condition for the total force calculated at both the grid- and test-filter widths. The LES results are compared with measured data.