LES simulation of an elliptic cylinder in the subcritical regime using a modified filtered linear discretization approach

This paper presents a Large Eddy Simulation (LES) of an elliptic cylinder with an aspect ratio of 2, using the WALE sub-grid scale model in OpenFOAM. The simulation is conducted in the subcritical flow regime at a Reynolds number of 3900, utilizing a modified filtered linear discretization technique for the divergence terms that ensures a balance between accuracy and stability, while providing a better representation of the energy spectrum. The results are compared with those of previous studies on circular cylinders. The findings indicate that the elliptic cylinder exhibits higher mean drag, primarily due to increased pressure drag on the frontal area, with lower pressure drag on the rear side compared to the circular cylinder, while the temporal lift exhibited sinusoidal behavior with a single distinct frequency. No significant variation is observed in the separation point or recirculation zone length. Time-averaged turbulent flow parameters reveal elevated levels of normalized Reynolds stresses, suggesting earlier shear-layer roll-up and transition, which are influenced by the elliptic cylinder's reduced afterbody.