Large-Eddy Simulation of Turbulent Flow Past a Square Cylinder Confined in a Channel

Turbulent flow past a square cylinder confined in a channel is numerically investigated by large eddy simulation (LES). The main objectives of this study are to extensively verify the experimental results of Nakagawa et al. [Exp. Fluids 27(3) (1999) 284] by LES and to identify the features of flows past a square cylinder confined in a channel in comparison with the conventional one in an infinite domain. The LES results obtained are in excellent agreement with the experiment both qualitatively and quantitatively. The well-known K a a vortex shedding is observed. However, the vortices shed from the cylinder are significantly affected by the presence of the plates; mean drag and fluctuation of lift force increase significantly. Furthermore, periodic and alternating vortex-rollups are observed in the vicinity of the plates. The rolledup vortex is convected downstream together with the corresponding K a a vortex; they form a counterrotating vortex pair. It is also revealed that the cylinder greatly enhances mixing process of the flow. � 2003 Elsevier Ltd. All rights reserved.