Abstract Different flow models have been proposed for the flow around surface-mounted finite-height square prisms, but there is still a lack of consensus about the origin and connection of the streamwise tip vortices with the other elements of the wake. This numerical study was performed to address this gap, in addition to clarifying the relationship of the near-wake structures with the far wake and the near-wall flow, which is associated with the fluid forces. A large-eddy simulation approach was adopted to solve the flow around a surface-mounted finite-height square prism with an aspect ratio of AR = 3 and a Reynolds number Re = 500. The mean drag and normal forces and the bending moment for the prism were quantitatively compared in terms of skin-friction and pressure contributions, and related to the near-wall flow. Both three-dimensional visualizations and planar projections of the time-averaged flow field were used to identify, qualitatively, the main structures of the wake, including the horseshoe vortex, corner vortices and regions of high streamwise vorticity in the upper part of the wake. These features showed the same qualitative behavior as reported in high Reynolds number studies. It was found that some regions of high streamwise vorticity magnitude, like the tip vortices, are associated with the three-dimensional bending of the flow, and the tip vortices did not continuously extend to the free end of the prism. The three-dimensional flow analysis, which integrated different observations of the flow field around surface-mounted finite-height square prisms, also revealed that the mean near-wake structure is composed of two sections of different origin and location of dominance.

中文翻译：

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表面安装的有限高度方形棱柱平均尾流中的空气动力和三维流动结构

摘要 针对表面安装的有限高度方形棱柱周围的流动，人们提出了不同的流动模型，但关于流向尖端涡流的起源和与尾流其他元素的联系仍缺乏共识。除了阐明近尾流结构与远尾流和与流体力相关的近壁流之间的关系外，还进行了这项数值研究以解决这一差距。采用大涡模拟方法求解纵横比 AR = 3 和雷诺数 Re = 500 的表面安装的有限高度方形棱柱周围的流动。棱镜在皮肤摩擦和压力贡献方面进行了定量比较，并与近壁流动有关。时均流场的三维可视化和平面投影都用于定性识别尾流的主要结构，包括尾流上部的马蹄涡、角涡和高流向涡度区域。这些特征显示出与高雷诺数研究中报告的相同的定性行为。发现一些高流向涡量的区域，如尖端涡，与流动的三维弯曲有关，并且尖端涡没有连续延伸到棱柱的自由端。三维流动分析，集成了表面安装的有限高度方形棱柱周围流场的不同观察结果，