阶梯坝面坡度对阶梯面掺气特性及负压影响试验研究  

Experimental study on influence of stepped overflow dam slope on aerated characteristics and negative pressure of step surface

作　　者：邱毅 杨具瑞[1] 陈卫星 任中成 QIU Yi;YANG Jurui;CHEN Weixing;REN Zhongcheng(Modern Agricultural Engineering College,Kunming University of Science and Technology,Kunming,Yunnan 650500,China)

机构地区：[1]昆明理工大学现代农业工程学院,云南昆明650500

出　　处：《排灌机械工程学报》2021年第8期811-817,共7页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(51569010)。

摘　　要：为探求高水头、大单宽流量下阶梯坝面坡度对宽尾墩—阶梯溢流坝—消力池一体化联合消能方式的阶梯面掺气特性及负压的影响,以阿海水电站为原型,采用速度比尺和长度比尺分别建立运输方程,引入水气两相流VOF和三维RNG紊流模型.利用几何重建格式来迭代生成自由水面,对51.34°,53.13°,56.98°这3种阶梯面坡度进行数值模拟研究.研究结果表明,坡度增加,阶梯面掺气空腔长度先增加后减小;当坡度为53.13°时,阶梯面掺气空腔长度最长,为7.5m.阶梯面掺气浓度变化与掺气空腔长度变化规律一致,坡度增加,阶梯面掺气浓度先增加后降低,各方案空腔段后掺气浓度均存在小于阶梯面最低保护掺气浓度3%,此掺气浓度下阶梯面会发生空蚀破坏.阶梯面负压呈双峰分布,最大负压峰值出现在第2峰值处,负压双峰值随坡度增加而增大,当坡度为56.98°时,负压最大,值为-42.34kPa.In order to explore the influence of the slope of the stepped dam face under high water head and large single wide flow rate on the aerated characteristics of the step face and negative pressure of the integrated joint energy dissipation method of the wide tail pier—stepped overflow dam—energy dissipation tank,taking Ahai Hydropower Station as a prototype,the transport equations were established using the speed scale and the length scale respectively,the VOF and three-dimensional RNG turbulence models of water-gas two-phase flow were introduced,and the geometric reconstruction format was used to iteratively generate free water surfaces.Three slopes of 51.34°,53.13°and 56.98°were studied by numerical simulation.The results show that when the slope increases,the length of the aerated cavity on the step surface increases first and then decreases.When the slope is 53.13°,the length of the aerated cavity on the step surface is the longest,up to 7.5 m.The change of the aerated concentration of the step surface is consistent with the change of the length of the aerated cavity,the slope increases,the aeration concentration of the step surface increases first and then decreases,and the aeration concentration after the cavity section of each scheme is less than 3%of the minimum protective aeration concentration of the step surface.At this aeration concentration,cavitation damage will occur on the step surface.The negative pressure of the step surface is bimodal,and the maximum negative pressure peak appears at the second peak.The double peak of negative pressure increases with the slope.When the slope is 56.98°,the negative pressure is the largest,up to-42.34 kPa.

关 键 词：坝面坡度 三维数值模拟 水气两相流 掺气空腔 负压 

分 类 号：TV135.2[水利工程—水力学及河流动力学]