论文部分内容阅读
有压闸室设置通气孔能够改善闸门启闭过程中的流态、脉动压力和启闭力特性,但同时可能带来通气孔下游附近的空蚀空化问题和通气孔内风速过大问题。利用1∶35水力学物理模型,针对4种通气孔布置形式的风速和空化特性开展了常压和减压模型试验。结果表明,通气孔断面面积越小,孔内风速越大;设置2个通气孔时,通气孔直径从1.2m减小到0.8m,能使空化噪声相对能量降低65%;在排沙洞出口段设置10m长圆管段后,能将空化噪声相对能量降低61.5%;排沙洞出口的跌坎高度对通气孔的空化特性影响不大。该结果对类似工程具有重要参考意义。
Ventilation with pressure-lock chamber can improve the fluid flow, pressure fluctuation and opening-closing force during opening and closing of the gate, but at the same time it may cause cavitation cavitation near the downstream of the vent hole and excessive wind speed in the vent hole. The 1: 35 hydraulics physical model was used to carry out atmospheric and decompression model tests for the wind speed and cavitation characteristics of four kinds of vent layouts. The results show that the smaller the cross-sectional area of the vent, the greater the wind speed in the hole. When two vents are provided, the diameter of the vent decreases from 1.2m to 0.8m, and the relative energy of cavitation noise can be reduced by 65% After setting the length of 10m long circular section in the outlet section, the relative energy of cavitation noise can be reduced by 61.5%. The height of the falling ridge at the outlet of the sand discharge tunnel has little effect on the cavitation characteristics of the vent. This result is of great significance to similar projects.