Large Eddy Simulation of the Flow across a Rotating Circular Cylinder

Abstract

Turbulent flow across a rotating circular cylinder is numerically investigated for five Reynolds numbers and five rotational speeds. Large Eddy Simulation (LES) method with Smagorinsky subgrid scale model is used for this purpose. Variations of the aerodynamics forces and the flow structure with spin ratio and Reynolds number are studied. The results showed that for the range of studied Reynolds numbers, drag force decreases with both spin ratio and Reynolds number, but lift force increases with spin ratio and decreases with Reynolds number. In case of flow structure, both the front stagnation point and the top separation point dislocate upward along the cylinder by increase of spin ratio and decrease of Reynolds number. Size of the vortices behind the cylinder is increased with both spin ratio and Reynolds number. Comparison of the LES results with the results from the other numerical or experimental works showed an acceptable correspondence. It is concluded that the LES method can be applied to highly recirculating flows with good level of accuracy and low computational cost.