Large-Eddy Simulation of Turbulent Flow Around a Finite-Height Wall-Mounted Square Cylinder Within a Thin Boundary Layer

In this paper, large-eddy simulation (LES) has been performed to investigate the turbulent wake behind a wall-mounted square cylinder. The flow features a relatively high cylinder aspect ratio of 4, a Reynolds number of 12,000 (based on the free-stream velocity and cylinder side length), and a thin developing boundary layer with a thickness of only 18 % of the obstacle height. These characteristics of the flow impose challenges to LES for accurate simulation of large energetic eddies induced by the cylinder and their intense interactions with the thin developing boundary layer. The coherent flow structures around the cylinder have been studied based on the instantaneous and time-averaged resolved velocity and pressure fields. The local kinetic energy transfer between the resolved and subgrid scales and the streamwise evolution of the subgrid-scale viscosity have been investigated to provide physical insights into the subgrid-scale dynamics. The LES predictions of the flow statistics have been validated against a set of recently reported wind-tunnel experimental data.