Response characteristics of vortex around the fixed and freely rotating rectangular cylinder with different width to height ratios

摘要

This paper presents a numerical investigation for the response characteristics of vortex around the fixed and freely rotating rectangular cylinder about a fixed axis through its centroid. The direct-forcing/fictitious domain (DF/FD) method is used to realise fluid-structure interaction (FSI) problem. In order to identify the effect of Reynolds number and width to height ratio on the flow characteristics and structure motion by FSI, we consider flow over a rectangular cylinder in the range of 50 ≤ Re ≤ 150 and 0.2 ≤ W/H ≤ 1.0, where Re and W/H are the Reynolds number and the width to height ratio. We also compare the freely rotating cylinder case with the fixed cylinder case. In the freely rotating case, the motion of rectangular cylinder is classified into the two different regimes. In the first regime, the rectangular cylinder exhibits periodic oscillation behaviour. In the second regime, it reveals autorotation. All the cases show the periodic oscillation behaviour except the cases of Re = 100 and 150 with W/H = 1.0 whose motion is autorotation.