Large-Eddy Simulations of the Accelerating Flow Around a Square Cylinder

The present work aims at investigating the high-Reynolds accelerating flow around a cylinder with a square cross-section. This is a classic shape of interest for wind-engineering applications, typical, e.g., of skyscrapers and towers. Despite the simple geometry, the flow features around square cylinders or prisms show a significant complexity. In particular, the flow is characterized by the shear-layer separation at the upstream edges. The separated shear layers undergo to Kelvin-Helmholtz instability, but they do not lose coherence until they form the von Karman vortex street in the wake. In terms of mean flow features, no reattachment is found on the lateral surface of the cylinder.