Analysis of inflow conditions on the flow past a wall-mounted square cylinder with OpenFOAM

Abstract

In this study, the flow mechanisms around wall-mounted structures was numerically investigated using Large Eddy Simulation (LES). A comparison was made between the uniform and non-uniform inflow condition to explore the impact of the inflow turbulence on the flow physics, the dynamic response and the hydrodynamic performance of the flow past the cylinder. Sparsity Promoting Dynamic Model Decomposition (SPDMD) was applied to select the dominant modes in the downstream flow field, and to further investigate the evolution of the temporal-spatial scales, as well as the mutual interaction among the wake, the cylinder and the boundary layer. The present study revealed a strong interference between the velocity fluctuations and the wake past the cylinder, in which leads to rapid energy transfer from large eddies to small eddies. Strong convection effects were also observed in the far wake region, where significant interference occurs during the energy transfer induced by fluctuating velocities and the coherent vortex structures. The model analysis successfully identifies the prominent modes of the wake dynamic characteristics under different inflow conditions. This study expands our understanding on the wakes past wall-mounted structures, particularly in terms of their evolution and instability mechanisms, and provides valuable insights for the design and optimization of future wall-mounted structures in engineering practice.