旋流竖井起旋室水气两相流数值模拟研究  

Numerical Simulation of Two-phase Flow Processes Invortex Chamber on Vortex Drop Shaft Spillway

作　　者：何红 尹进步[1] 徐自立[1] 杜振康 朱光明 HE Hong;YIN Jin-bu;XU Zi-li;DU Zhen-kang;ZHU Guang-ming(College of Water Resources and Architectural Engineering,Northwest Agricultural and Forestry University,Yangling 712100,Shaanxi Province,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《中国农村水利水电》2023年第4期244-250,256,共8页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(51509312)。

摘　　要：起旋室是旋流竖井泄洪洞的主要组成部分,为克服传统模型试验对空腔旋流的量测限制,利用RNG k-ε湍流模型对起旋室内气液两相流进行数值计算,获得起旋室内旋流运动的水力特性。计算结果表明近壁面压强沿流程增大,断面压强沿半径趋近线性增加,压强等值线呈现以起旋室中心为圆心的同心圆分布;起旋室同一断面上轴向流速随半径r先减小后增大,切向流速随半径先增大后减小,表现出组合涡分布特征;组合涡指数n处于-0.4~1之间且随半径增大而增大,表明水流从准自由涡主导转变为准强迫涡主导;起旋室内水流运动主要为切向和轴向运动为主,且沿程由切向运动主导逐渐向轴向运动主导转变,与旋流角α沿程变化特征相符合。The vortex chamber is the main component of the vortex drop shaft spillway.To overcome the limitation of measuring cavity swirl in traditional model tests.The RNG k-εturbulence model is used to numerically calculate the gas-liquid two-phase flow in the vortex cham⁃ber,and the hydraulic characteristics of the swirling flow in the vortex chamber are obtained.The calculation results show that the near-wall pressure in the vortex chamber is affected by the contraction section of the shaft and increases gradually with the elevation decrease.The pres⁃sure of the cross-section is symmetrically distributed along the radial direction and increases almost linearly with the radius increase.The pressure isolines on the cross-section roughly conform to the concentric circle distribution in the center of the vortex chamber,which is most dense at the air-water interface,and gradually becomes sparse toward the wall.The tangential velocity on the cross-section of the vortex chamber shows an axisymmetric distribution law,which increases with the increase in the radius,decreases with the increase in the radius at a certain distance from the wall of the vortex chamber,and then drops sharply to 0 somewhere near the wall.The axial velocity on the crosssection of the vortex chamber is the largest at the center of the section cavity,decreases first and then increases with the change in radius,and rapidly decreases to 0 at a specific position near the wall.Tangential and axial flow are the main types of three-dimensional swirling flow in the vortex chamber.As the flow moves,the flow changes from tangential flow to axial flow.The value of the near-wall swirl angle in the vortex chamber varies from 60°to 80°,and the significant value of the swirl angle in the vortex chamber indicates that the water flow in this area is mainly tangential.With the elevation decrease,the swirl angle decreases along the way,meaning that under axial gravity and with the movement of water flow,the flow in the vortex chamber changes from tangential to axia

关 键 词：旋流竖井 起旋室 数值模拟 水力特性 组合涡 

分 类 号：TV135.2[水利工程—水力学及河流动力学]