Numerical study of three-dimensional flows around two identical square cylinders in staggered arrangements
Numerical study of three-dimensional flows around two identical square cylinders in staggered arrangements
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交错排列的两个相同方形圆柱体周围三维流动的数值研究
DOI：
10.1063/1.2194077
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发表时间：
2006-04
影响因子：
4.6
通讯作者：
中科院分区：
文献类型：
--
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为了解高密度高层建筑物间空气污染物扩散规律，本文对雷诺数为250、入射角为0、入射速度矢量与柱中心连线夹角为45°时，两个相同的交错布置的方形柱体TISC的三维绕流进行了数值模拟。的阻力和升力，其均方根值，和斯特劳哈尔数的水平间距的依赖性进行了评估。发现上游方柱SC-Ⅰ的阻力和升力之间的相关系数接近于1，而下游方柱SC-Ⅱ的相关系数沿展向沿着呈波浪形。波长和震级与柱间距密切相关。对二次涡拟序结构和一次涡结构进行了分析和讨论。© 2006美国物理研究所。DOI：10.1063/1.2194077围绕两个相同方形圆柱体的气流TISC是建筑物和许多其他工程结构周围气流的理想化表示。建筑物周围遇到的流动可以从低Re数蠕动流到充分发展的湍流，这取决于风力条件。在低雷诺数条件下的TISC流的研究是有关的室内空气污染物的分散的理解，特别是病原体的气溶胶周围的高密度，高层建筑物，在最近的SARS爆发所见证的。1由于方柱间的差距流动、近尾流干扰以及可能出现的远尾流的影响，需要对某些重要的流动特性进行研究。然而，相应的数值工作仍然很少，而最近的研究进行了圆柱流动，其中大部分是实验工作。2.研究了两圆柱错列交叉绕流问题，当螺距比从1到5，入射角从0到90°，雷诺数从850到1900时，绕流中存在9种流型。有人建议，涡脱落频率更恰当地与个别剪切层，而不是与个别圆柱体;更具体地说，两个剪切层从下游的圆柱体往往脱落的涡流在不同的频率。间隙流效应的存在导致了多圆柱绕流的复杂流型，不仅在一次流中，而且当Re超过临界过渡值时，在二次流中也出现了复杂的流型。因此，圆柱之间的间距和相对于自由端的取向是影响流动干扰的主要特征，这可能导致用于抑制多个圆柱的旋涡脱落的大多数方法无效。3 - 6多圆柱体尾流的间距效应已被广泛测量和报道，7 - 10但相关情况是并排或串联圆柱体布置。此外，在大多数这些研究中3 - 10，
With the aim to understand air pollutant dispersion among high-density, high-rise buildings, this paper presents the numerical results of three-dimensional flows around two identical square cylinders TISCs in staggered arrangements at a Reynolds number of 250 and zero incident angle when the angle between the incoming velocity vector and the line connecting the centers of the cylinders is 45°. The dependence of the drag and lift, their root mean square values, and the Strouhal number on the horizontal spacing have been evaluated. It was found that the correlation coefficients between the drag and lift of the upstream square cylinder SC-I were close to unity, with those for the downstream square cylinder SC-II exhibiting a wavy form along the spanwise direction. The wavelength and the magnitude are closely related to the cylinder spacing. Secondary vortex coherent structures as well as the primary vortex structures were reported and discussed. © 2006 American Institute of Physics. DOI: 10.1063/1.2194077 Flows around two identical square cylinders TISCs are idealized representation of airflows around buildings and many other engineering structures. Flows encountered around buildings can vary from low Re number creeping flows to fully developed turbulent flows, depending on wind conditions. The study of the TISC flow at low Reynolds number conditions is related to the understanding of the dispersion of indoor air pollutants, and particularly pathogenladen aerosols around high-density, high-rise buildings, as witnessed in the recent SARS outbreak. 1 Owing to the effect of the gap flow between the two square cylinders, the nearwake interference, and the possible far-wake emergence, certain important flow characteristics need to be explored. However, the corresponding numerical work remains scarce, while more recent studies were conducted on circular cylinder flows, and most of them are experimental work. 2 It was reported that for the flow around two staggered identical circular cylinders in cross-flow, there exist nine patterns when the center-to-center pitch ratio varies from 1 to 5, and the angle of incident changes from zero to 90°, with Reynolds number ranging from 850 to 1900. It was suggested that the vortex shedding frequencies are more properly associated with individual shear layers rather than with individual circular cylinders; more specifically, the two shear layers from the downstream cylinder often shed vortices at different frequencies. The presence of gap flow effects results in complicated patterns of multiple cylinders flow, not only in the primary flow but also in the secondary flows when the Re is beyond the critical transitional value. Therefore, the spacing between the cylinders and the orientation relative to the freestream are dominant features that affect the flow interference, which might lead to the ineffectiveness for most methods used in suppressing the vortex shedding from multiple cylinders. 3‐6 The spacing effect on the multicylinder wake flow has been measured and reported extensively, 7‐10 but the relevant situation is either for side-by-side or tandem cylinder arrangement. Furthermore, in most of these studies 3‐10 the associa
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影响因子：
3.7
作者：
OKAJIMA, A
通讯作者：
OKAJIMA, A
DOI：
10.1137/0913035
发表时间：
1992-03-01
期刊：
SIAM JOURNAL ON SCIENTIFIC AND STATISTICAL COMPUTING
影响因子：
--
作者：
VANDERVORST, HA
通讯作者：
VANDERVORST, HA
DOI：
10.1016/s0167-6105(01)00109-x
发表时间：
2002
影响因子：
4.8
作者：
Zuojin Zhu;Hongxing Yang
通讯作者：
Zuojin Zhu;Hongxing Yang
影响因子：
4.1
作者：
T. Baker
通讯作者：
T. Baker
影响因子：
3.7
作者：
M. Zdravkovich
通讯作者：
M. Zdravkovich