ABSTRACT

The transient flow behind a bluff body is a common phenomenon in engineering applications. However, most of the research attention is fully developed flow, rather than the initial stages of flow formation. In this work, the transient flow in the initial stage behind a translationally and rotationally started cylinder with multiple control cylinders is investigated by the dynamic mesh method. The solutions in this paper agree well with the experimental data and numerical solutions reported in the open literature. The results show that the shedding of the vortex from the transient flow in the initial stage slows down with the increase of the number of control cylinders. The magnitude of the hydrodynamic coefficient of the main cylinder decreases with the increase of diameter ratios, but the fluctuations and instability of the transient flow are generated at the same time.

摘要

钝体后面的瞬态流动是工程应用中的常见现象。然而，大多数研究关注的是完全发展的流动，而不是流动形成的初始阶段。在这项工作中，通过动态网格方法研究了具有多个控制气缸的平移和旋转启动气缸后面的初始阶段的瞬态流动。本文中的解决方案与公开文献中报道的实验数据和数值解决方案非常吻合。结果表明，随着控制缸数量的增加，初始阶段瞬态流中涡流的脱落速度减慢。主缸水动力系数的大小随着直径比的增加而减小，