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 on 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– ε (RKE), Wilcox k– ω (WKO) and Shear-Stress-Transport k– ω (SST), which were assessed based on their comparative performances in predicting some important flow field characteristics of the near-wake region of the experimental circular cylinder flow. 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.