基于正交设计的组合型式阶梯掺气特性分析  

Analysis of combined type step aeration characteristics based on orthogonal design

作　　者：陈卫星 杨具瑞[1] CHEN Weixing;YANG Jurui(Faculty of Agriculture and Food,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学农业与食品学院,云南昆明650500

出　　处：《武汉大学学报（工学版）》2021年第11期1008-1014,共7页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:51569010)。

摘　　要：为探讨防止阶梯处空蚀空化破坏的措施,通过极差和方差等正交设计方法,对9种"大阶梯+凸起型阶梯"组合型式阶梯水工模型试验的掺气空腔长度、掺气浓度以及负压等测量结果进行正交试验设计分析,结果发现:过渡阶梯段凸起型阶梯的数量对阶梯溢流坝面掺气的影响程度高于凸起型阶梯尺寸;掺气空腔长度、掺气浓度及负压与凸起型阶梯数量的关系不呈线性分布,过渡阶梯段存在2个凸起型阶梯时,掺气效果较好;凸起型阶梯可以较大地扰动水流,优化水流的掺气特性,但是凸起型阶梯尺寸的选择对掺气特性也相当重要;当过渡阶梯段的首级阶梯为大阶梯、其余阶梯尺寸为16.67 mm×18.75 mm的凸起型阶梯时,阶梯面掺气最充分,空腔长度为14.58 cm,掺气浓度为15.61%,此时负压也最小,为-0.409 kPa。In order to explore the measures to prevent cavitation damage at the step, orthogonal design methods such as range and variance were used to analyze the measurement results of aerated cavity length,aerated concentration and negative pressure of 9 kinds of "big step+raised step" combination hydraulic model tests. It is found that the number of convex ladder of the transition stepped section has a higher influence on the aeration of the stepped spillway surface than the convex ladder size. The relationships between the length of the cavity,the aeration concentration and the negative pressure,and the number of the convex ladder are not linear.When there are two convex ladders in the transition section,the aeration effect is better. The convex ladder can greatly disturb the water flow, optimize the aeration characteristics of the water flow,but the selection of the convex step size is also very important for the aeration characteristics.When the first step of the transition section is a large step,and the other steps are raised steps with the size of 16.67 mm×18.75 mm,the ladder surface aeration is the most adequate.At this time,the cavity length is 14.58 cm,the aeration concentration is 15.61%, and the negative pressure is also the smallest,which is-0.409 kPa.

关 键 词：大阶梯 凸起型阶梯 正交试验设计 阶梯溢流坝 掺气空腔 掺气浓度 负压 

分 类 号：TV135.2[水利工程—水力学及河流动力学]