摘要
空化泡溃灭常发生在水力机械过流部件的曲壁面附近并造成空蚀。为探究其机理,该文综合考虑非凝气体影响下的汽-液相变传质作用和热力学效应,建立空化泡数值模拟模型,并以此深入研究曲面附近空化泡多周期演变及其对壁面的破坏作用。结果表明在任一特征距离下,空化泡的溃灭时间随曲率的增大而增大。而曲率一定时,溃灭时间随空化泡与壁面的特征距离ξ的增大先增大后减小:ξ=1.0时,溃灭时间最大;ξ≤1.0时,反弹半径几乎不随曲率发生变化;ξ>1.0时,反弹半径随着曲率的增大而增大。空化泡溃灭后所产生的冲击波会引起壁面压力峰值:0<ξ<1.4时,空化泡溃灭时产生的高速射流也会引起壁面压力峰值;ξ=0时,壁面温度最大,达到了11 700 K;ξ>2.0时,壁面压力冲量随着曲率的增大而增大;0<ξ<2.0时,则相反。此外,壁面导热量则随着曲率的增大而减小。该研究可为工程界防止空化空蚀提供参考。
The collapse of cavitation bubbles often occurs near the curved surface of hydraulic machinery overflow components,and causes cavitation erosion.In order to explore its mechanism,this paper comprehensively considers the mass transfer and thermodynamic effects of vapor-liquid phase change under the influence of non-condensable gases,constructs a newly numerical model of cavitation bubbles,and applies it to the in-depth study of the multi-cycle evolution of cavitation bubbles near the curved surface and their destructive effects on walls.At any feature distance,the collapse time of cavitation bubbles increases with the increase of curvature.When the curvature is constant,the collapse time first increases and then decreases with the increase of non-dimensional feature distanceξ,and the maximum value is achieved atξ=1.0.Whenξ≤1.0,the rebound radius hardly changes with curvature.Whenξ>1.0,the rebound radius increases with the increase of curvature.The shock wave after the collapse of cavitation bubbles can cause peak wall pressure.When 0<ξ<1.4,the high-speed jet generated by the cavitation bubbles can also cause a peak wall pressure.Whenξ=0,the maximum wall temperature reached 11700 K.Whenξ>2.0,the impulse of wall pressure increases with the increase of curvature,but it is the opposite when 0<ξ<2.0.Besides,the wall heat transfer decreases with the increase of curvature.This study can provide reference for the engineering field in preventing cavitation and cavitation erosion.
作者
田磊
张永学
尹建勇
吕良
张金亚
朱建军
Tian Lei;Zhang Yongxue;Yin Jianyong;LüLiang;Zhang Jinya;Zhu Jianjun(College of Mechanical and Transportation Engineering,China University of Petroleum-Beijing,Beijing 102249,China;Beijing Key Laboratory of Process Fluid Filtration and Separation,China University of Petroleum-Beijing,Beijing 102249,China;Electrical Engineering College,Guizhou University,Guiyang 550025,China;School of Mechatronic Engineering,Suzhou Vocational University,Suzhou 215104,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2023年第6期996-1006,共11页
Chinese Journal of Hydrodynamics
基金
国家自然基金项目(52179094)。
关键词
空化泡
相变模型
曲壁面
压力冲量
导热量
Cavitation bubbles
Phase change model
Curved wall
Pressure impulse
Heat transfer
