Effect of Vortex Generators on the Flow Around a Circular Cylinder: Computational Investigation with Two-Equation Turbulence Models

Abstract: The paper presents a comparative study based on the 3D computational simulations of the flow around a circular cylinder fitted with vortex generators, benefiting from a series of dedicated model tests conducted in a large circulating water tunnel. The effect of the vortex generators is presented with comparisons including the bare cylinder with no vortex generator case and related experimental data. Incompressible, unsteady Reynolds- Averaged-Navier-Stokes (URANS) computations were performed by using three different two-equation turbulence models, which were Realizable k-ε, Wilcox k-ω, and Shear-Stress-Transport k-ω models. The numerical calculations emphasized the effectiveness and the performance enhancing character of the vortex generators. Many key findings of the measurements such as the elongation of the near-wake, the extension of the shear layers, the decrease of the stress components and the weakening of the vortices were successfully reproduced with the computations. Significant drag reduction was observed in both experimental and computational study due to the application of the vortex generators.

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