Effect of blockage on critical parameters for flow past a circular cylinder
Effect of blockage on critical parameters for flow past a circular cylinder
复制标题
DOI：
10.1002/fld.1098
复制
发表时间：
2006-03
影响因子：
1.8
通讯作者：
B. Kumar;S. Mittal
中科院分区：
文献类型：
--
作者：
B. Kumar;S. Mittal
本文研究了计算区域的侧边界位置对圆柱绕流失稳临界参数的影响。通过稳定化有限元方法对不可压缩流动的控制方程进行线性稳定性分析，以预测尾流的主要不稳定性。利用子空间迭代法求解有限元离散方程所产生的广义本征值问题，得到最不稳定的本征模。计算是在很大的阻塞范围内进行的，0.005 <$D/H <$0.125，其中D是圆柱的直径，H是区域的横向宽度。观察到临界Re随堵塞的非单调变化。研究发现，随着堵塞的增加，临界雷诺数的不稳定性的发病先减少，然后增加。然而，观察到在不稳定性开始时，随着堵塞的增加，无量纲脱落频率单调增加。增加的阻塞抑制了低频模式，为高频模式让路。在过去的各种研究中，发现堵塞在不稳定性开始时的无量纲涡脱落频率数据的分散中起着重要作用。版权所有© 2005年约翰威利父子有限公司。
The effect of location of the lateral boundaries, of the computational domain, on the critical parameters for the instability of the flow past a circular cylinder is investigated. Linear stability analysis of the governing equations for incompressible flows is carried out via a stabilized finite element method to predict the primary instability of the wake. The generalized eigenvalue problem resulting from the finite element discretization of the equations is solved using a subspace iteration method to get the most unstable eigenmode. Computations are carried out for a large range of blockage, 0.005⩽D/H ⩽0.125, where D is the diameter of the cylinder and H is the lateral width of the domain. A non‐monotonic variation of the critical Re with the blockage is observed. It is found that as the blockage increases, the critical Re for the onset of the instability first decreases and then increases. However, a monotonic increase in the non‐dimensional shedding frequency at the onset of instability, with increase in blockage, is observed. The increased blockage damps out the low‐frequency modes giving way to higher frequency modes. The blockage is found to play an important role in the scatter in the data for the non‐dimensional vortex shedding frequency at the onset of the instability, from various researchers in the past. Copyright © 2005 John Wiley & Sons, Ltd.