多孔涂层对圆柱体出水动力学的影响

中文摘要 AI 辅助

本文通过实验研究了多孔涂层对圆柱体出水动力学的影响。将直径为30毫米的实心圆柱芯外包覆一层10毫米厚的多孔泡沫层，孔密度分别为10、20和60孔每英寸（PPI），并与相同外径的光滑圆柱进行比较。实验在雷诺数1.50×10⁴≤Re≤5.00×10⁴和弗劳德数0.37≤Fr≤4.08范围内进行。时间分辨粒子图像测速技术用于表征尾流和重构压力场，而本征正交分解（POD）用于分析其能量组织。所有多孔圆柱相比光滑圆柱均降低了自由表面高程，其中60 PPI通常获得最大降低。然而，水下尾流并未简单减弱。多孔情况通常产生更大的环量和涡旋面积，且对孔密度和操作条件呈非单调依赖。10 PPI圆柱经常产生最大的涡旋区域，而60 PPI在Fr=1.02、2.00和4.08时在涡旋内产生更强的负压以及最大的涡旋相关压力亏损。在水下接近接触过程中，该压力亏损与环量强烈协同演化，皮尔逊相关系数通常在0.90至0.98之间。POD显示9至18个模态可恢复95%的模态能量，其中20 PPI仅需9至10个模态。总体而言，多孔涂层重新组织了尾流强度、范围、压力特征和能量结构，同时降低了自由表面响应。

英文摘要

The effect of a porous coating on the water-exit dynamics of a circular cylinder is investigated experimentally. Cylinders comprising a $30~\mathrm{mm}$ solid core surrounded by a $10~\mathrm{mm}$-thick porous foam layer with pore densities of 10, 20, and 60 pores per inch (PPI) are compared with a smooth cylinder of the same outer diameter. Experiments are performed over $1.50\times10^{4}\leq Re\leq5.00\times10^{4}$ and $0.37\leq Fr\leq4.08$. Time-resolved particle image velocimetry characterizes the wake and reconstructed pressure field, while proper orthogonal decomposition (POD) examines its energetic organization. All porous cylinders reduce free-surface elevation relative to the smooth cylinder, with the largest reduction generally obtained for 60 PPI. The submerged wake, however, is not simply weakened. Porous cases generally develop larger circulation and vortex area, with a non-monotonic dependence on pore density and operating condition. The 10 PPI cylinder frequently produces the largest vortex region, whereas 60 PPI generates stronger negative pressure within the vortex and the largest integrated vortex-associated pressure deficit for $Fr=1.02$, $2.00$, and $4.08$. During the submerged approach to contact, this pressure deficit co-evolves strongly with circulation, with Pearson correlation coefficients typically between $0.90$ and $0.98$. POD shows that 9--18 modes recover 95\% of the modal energy, with 20 PPI requiring only 9--10 modes. Overall, porous coating reorganizes wake strength, extent, pressure signature, and energetic structure while reducing the free-surface response.

发表机构

• Université de Liège（列日大学）
• University College London（伦敦大学学院）
• Indian Institute of Technology Hyderabad（印度海德拉巴理工学院）

机构由 AI 辅助整理，请以论文原文为准。