Cavitation Inception and Head Loss Due to Liquid Flow Through Perforated Plates of Varying Thickness
Cavitation Inception and Head Loss Due to Liquid Flow Through Perforated Plates of Varying Thickness
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DOI：
10.1115/1.4023407
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发表时间：
2013-03
影响因子：
2
通讯作者：
Daniel Maynes;G. Holt;Jonathan D. Blotter
中科院分区：
文献类型：
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作者：
Daniel Maynes;G. Holt;Jonathan D. Blotter
本文报告了水流高速通过不同厚度和流动面积与管道面积比的多孔板引起的损失系数和空化发生的实验研究结果。总体板损失系数、空化起始点和临界空化发生点是射孔尺寸、孔数和板厚度的函数。研究中总共考虑了16块板，总穿孔面积与管道面积之比范围为0.11至0.6，板厚度与穿孔孔径范围为0.25至3.3，穿孔数量为4至1800。板安装在闭合水流回路的测试段中。结果揭示了板损失系数与总自由面积比以及板厚度与穿孔孔径比之间的复杂依赖性。一般来说，损耗系数随着自由面积比和厚度与孔径比的增加而减小。提出了一个基于数据的模型，用于预测具有非圆孔的多孔板的损耗系数。此外，数据表明，空化起始点和临界空化点的空化数随着自由面积比的增加而增加。然而，就厚度与孔径之比而言，初始空化数在 0.5 至 1.0 之间的比率处呈现局部最大值。提出了经验模型，可以预测空化起始点和临界空化开始点，并与单孔孔板行为进行比较。
This paper reports results of an experimental investigation of the loss coefficient and onset of cavitation caused by water flow through perforated plates of varying thickness and flow area to pipe area ratio at high speeds. The overall plate loss coefficient, point of cavitation inception, and point where critical cavitation occurs are functions of perforation hole size, number of holes, and plate thickness. Sixteen total plates were considered in the study with the total perforation hole area to pipe area ratio ranging from 0.11 and 0.6, the plate thickness to perforation hole diameter ranging from 0.25 to 3.3, and the number of perforation holes ranging from 4 to 1800. The plates were mounted in the test section of a closed water flow loop. The results reveal a complex dependency between the plate loss coefficient with total free-area ratio and the plate thickness to perforation hole diameter ratio. In general, the loss coefficient decreases with increasing free-area ratio and increasing thickness-to-hole diameter ratio. A model based on the data is presented that predicts the loss coefficient for multiholed perforated plates with nonrounded holes. Furthermore, the data show that the cavitation number at the points of cavitation inception and critical cavitation increases with increasing free-area ratio. However, with regard to the thickness-to-hole diameter ratio, the cavitation number at inception exhibits a local maximum at a ratio between 0.5 and 1.0. Empirical models to allow prediction of the point of cavitation inception and the point where critical cavitation begins are presented and compared to single hole orifice plate behavior.