截止阀内流道空化形态演变规律及空蚀损伤试验研究  

Experimental study on cavitation evolution law and cavitation damage of stop valve

作　　者：黄立华 王江云 侯琳倩 杨矞琦 HUANG Lihua;WANG Jiangyun;HOU Linqian;YANG Yuqi(China University of Petroleum-Beijing at Karamay,Karamay 834000,China;Beijing Key Laboratory of Process Fluid Filtration and Separation,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)克拉玛依校区,新疆克拉玛依834000 [2]过程流体过滤与分离技术北京市重点实验室,北京102249

出　　处：《流体机械》2022年第8期1-7,共7页Fluid Machinery

基　　金：国家自然科学基金项目(21106181);新疆维吾尔自治区自然科学基金项目(2020D01B62);中国石油大学(北京)克拉玛依校区科研启动基金项目(RCYJ2017B-02-002)。

摘　　要：为了研究阀门非对称结构流道空化损伤机理,采用高速摄像机针对一种特殊结构的空化室内空化演变过程进行试验分析,考察了不同空化状态下空泡初生、发展、脱落、分离或融合再生或直接溃灭的过程。结果表明,随流量增加,空化强度增大,空化状态从单空泡初生、脱落演变为下凸圆后方云状空化带,再发展为全流场超空化。固定狭缝3 mm宽度,空化指数在1224~652区间时,空化状态为泡状空化,空泡在上凸圆绕流135°边界层分离位置初生,经狭缝旋转与下凸圆空泡聚并、长大、溃灭,空泡演变周期约为40 ms;当空化指数在652~81区间时,空化状态为云状空化,微小空泡充满整个空化腔,在上、下凸圆后形成了高透光空泡团聚、溃灭区域,加剧空蚀损伤作用;当空化指数小于21时,出现超空化状态,微空泡溃灭引发的波动效应增大,阀门空蚀损伤速率达到极值。所得结果可为阀门非定常空化过程及阀门空蚀损伤分析提供理论基础。In order to study the cavitation damage mechanism of asymmetric flow channels of valves,the process of cavitation initiation,development,shedding,separation,fusion,regeneration or direct collapse was investigated for the cavitation cavity of a special structure under different cavitation conditions by using a high-speed camera.The results show that with the increase of the flow rate,the cavitation intensity increases,and the cavitation state evolves from the initiation and shedding of a single cavitation to the cloud shape cavitation state,and then to super-cavitation state of the full flow field.When the slit gap is 3 mm and the cavitation index is in the range of 1224~652,the cavitation state is the bubble cavitation state.Under this condition,the cavitation is initiated at the 135°boundary layer separation position of the upper convex circle.The bubble rotates through the slit and coalesces with the lower bubble,grows and collapses.The evolution period of the bubble is about 40 ms.When the cavitation index is in the range of 652~81,the cavitation cavity is in the state of cloud cavitation.the micro cavitation fills the whole cavitation cavity,forming an agglomeration and collapse area with high light transmittance cavitation,which intensifies the cavitation damage.As the cavitation index decreases below 21,the super-cavitation state appears,the fluctuation effect caused by micro cavitation collapse increases,and the degree of valve cavitation damage reaches the extreme value.The results can provide a theoretical basis for the analysis of unsteady cavitation process and valve cavitation damage.

关 键 词：突变流道 高速摄像 空泡演变 边界层分离 空泡溃灭 

分 类 号：TH137[机械工程—机械制造及自动化]