Flow past a rectangular cylinder close to a free surface

Abstract

Flow past rectangular cylinders represents an idealized flow around bluff bodies. Knowing the hydrodynamic properties of rectangular cylinders in a steady flow is of practical importance for many engineering applications. Although the unbounded flow past rectangular cylinders has been broadly studied, investigations on the flow around rectangular cylinders close to the free surface are limited. In the present study, two-dimensional multiphase simulations of flow past rectangular cylinders were conducted using RANS. The Mentor shear stress transport (SST) k - ω model and the volume of fluid (VoF) model were adopted. The Mentor SST k - ω model is capable of accurately predicting the flow past rectangular cylinders near the free surface when the width-to-length ratio is larger than 0.7. The effect of the depth-to-length ratio on the hydrodynamic properties of rectangular cylinders is affected by the width-to-length ratio and becomes significant when the depth-to-length ratio is lower than 1.0. The effect of the width-to-length ratio on the flow past rectangular cylinders near the free surface is different from that in an infinite domain. The findings from the present study can provide a deep understanding of the hydrodynamic properties of rectangular cylinders close to the free surface.