Effect of turbulence modelling on the computation of the near-wake flow of a circular cylinder

An evaluation of four well-known Reynolds-Averaged Navier-Stokes (RANS)-based turbulence models was performed in comparison with the results of a dedicated experimental measurement oil the near-wake of a circular cylinder in a large water (cavitation) tunnel using a state-of-the-art two-dimensional Digital Particle Image Velocimetry (DPIV) device. The turbulence models investigated were Spalart-Allmaras (S-A), Realizable k-epsilon (RKE), Wilcox k-omega (WKO) and Shear-Stress-Transport k-omega (SST), which were assessed based oil their comparative performances in predicting some important now field characteristics of the near-wake region of the experimental circular cylinder now. Within the flow range investigated in this study, which implied a cylinder diameter-based Reynolds Number of 41,300, the qualitative and quantitative comparisons revealed that the application of the SST model to the wall-bounded unsteady flow - that experienced severe adverse pressure gradient, massive flow separation and vortex shedding - presents more successful predictions compared to other models investigated for such challenging flow conditions. (C) 2009 Elsevier Ltd. All rights reserved.