Abstract

The flow around an staggered arrangement of seven cylinders is numerically studied using the finite element method to solve the two-dimensional and incompressible Navier—Stokes equations. The Reynolds number is 200 and the spacing ratios \(L{\text{/}}D\) = 1.1–5. In accordance with different hydrodynamic characteristics and vortex street arrangements, three distinct forms of wake flow can be identified, namely, the single bluff-body pattern (\(1.1 < L{\text{/}}D < 1.5\)), the deflected pattern (\(1.5 < L{\text{/}}D\) < 3), and the vortex impact pattern (\(3 < L{\text{/}}D < 5\)). For the further in-depth study of the characteristics of different wake patterns, the variations of the hydrodynamic forces on seven cylinders and the underlying mechanisms are analyzed and the wake structures are presented. The results of the analysis show that the gap flow under different wake patterns has different effects on the change of the hydrodynamic characteristics. It is found that the change of the wake structure is closely related to the change of the wake pattern.

中文翻译：

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低雷诺数下通过多缸流动的特性和干扰效应的数值研究

摘要

使用有限元方法对七个圆柱体的交错排列周围的流动进行了数值研究，以求解二维且不可压缩的Navier-Stokes方程。雷诺数为200，间距比\（L {\ text {/}} D \） = 1.1–5。根据不同的水动力特性和涡街布置，可以识别出三种不同的尾流形式，即单一的钝体模式（\（1.1 <L {\ text {/}} D <1.5 \）），偏转模式（\（1.5 <L {\ text {/}} D \）  <3）和涡流冲击模式（\（3 <L {\ text {/}} D <5 \））。为了进一步深入研究不同尾流形态的特征，分析了七个汽缸上的水动力的变化及其潜在机理，并提出了尾流结构。分析结果表明，不同尾流模式下的间隙流对水动力特性的变化具有不同的影响。发现尾流结构的变化与尾流模式的变化密切相关。