Abstract Wind tunnel experiments at a Reynolds number of Re = 6.5 × 104 were used to study the effect of aspect ratio and boundary layer thickness on the mean static pressure distribution on the free end of a surface-mounted finite-height cylinder. The cylinder's aspect ratio was changed in small increments from AR = 0.5 to AR = 11. Two different boundary layer thicknesses (relative to the cylinder diameter) were employed, δ/D = 0.6 and δ/D = 1.9. From analysis of the mean pressure contour plots, it was found that the sizes and locations of regions of lower pressure, adverse pressure gradient, and higher pressure, and the appearance of “eye-like spots”, are sensitive to both AR and δ/D. The adverse pressure gradient occurs just ahead of the mean reattachment line while the eye-like spots are related to termination points of the legs of the arch vortex within the free-end mean recirculation zone. The total normal force coefficient experienced by the cylinder is strongly influenced by the contribution of the wall shear stress on the sides of the cylinder, with a change in direction of the net vertical shear stress contribution occurring between AR = 7 and AR = 8 for both boundary layers.

中文翻译：

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明装有限高圆柱体自由端平均压力分布特性

摘要 通过雷诺数Re = 6.5 × 104 的风洞实验，研究了纵横比和边界层厚度对表面安装有限高度圆柱体自由端平均静压分布的影响。圆柱的纵横比以小增量从 AR = 0.5 更改为 AR = 11。采用了两种不同的边界层厚度（相对于圆柱直径），δ/D = 0.6 和 δ/D = 1.9。对平均压力等值线图的分析发现，低压、逆压梯度和高压区域的大小和位置，以及“眼状斑点”的出现，对 AR 和 δ/ D. 不利的压力梯度发生在平均再附着线之前，而眼状斑点与自由端平均再循环区内的拱形涡流腿的终止点有关。圆柱体承受的总法向力系数受圆柱体侧面壁面剪应力贡献的强烈影响，净垂直剪应力贡献的方向发生在 AR = 7 和 AR = 8 之间的变化边界层。