Direct numerical simulation of oscillatory flow around a circular cylinder at low Keulegan–Carpenter number
Direct numerical simulation of oscillatory flow around a circular cylinder at low Keulegan–Carpenter number
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DOI：
10.1017/s0022112010003691
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发表时间：
2010-09
影响因子：
3.7
通讯作者：
H. An;Liang Cheng;Ming Zhao
中科院分区：
文献类型：
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作者：
H. An;Liang Cheng;Ming Zhao
本文用直接数值模拟方法研究了圆柱绕流的正弦振荡流动。三维Navier-Stokes方程在Keulegan-Carpenter数KC较小的情况下用有限元法求解。通过流动显示，在一定频率范围内讨论了本二涡的产生和发展。据发现，本寺涡之间的间距是只有弱依赖于振荡的频率，但强烈相关的KC，因为它是包含KC占主导地位的三维特征的流动的控制方程内的条款。提出了KC与相邻涡间距之间的经验关系。三维稳定的流动结构内的旋涡被确定，它被发现，在高频率的稳定的流动是二维的，虽然瞬时流结构本身是完全三维的。
The Honji instability is studied using direct numerical simulations of sinusoidal oscillatory flow around a circular cylinder. The three-dimensional Navier–Stokes equations are solved by a finite element method at a relatively small value of the Keulegan–Carpenter number KC. The generation and subsequent development of Honji vortices are discussed over a range of frequency parameters by means of flow visualization. It is found that the spacing between Honji vortices is only weakly dependent on the frequency of oscillation, but is strongly correlated to KC because it is the terms within the governing equation containing KC that dominate the three-dimensional features of the flow. An empirical relationship between KC and the spacing between neighbouring vortices is proposed. The three-dimensional steady streaming structure within the vortices is identified and it is found that at high frequencies the steady streaming is two-dimensional although the instantaneous flow structure is itself fully three-dimensional.