尾水管涡作用下水轮机转轮叶片动水压力特性  

The hydrodynamic pressure characteristics acting on a turbine runner blade under the vortex rope in draft tube

作　　者：李兆军[1] 王玉江[1,2] 刘福秀[1] 黄钰钰 毛息军 LI Zhao-jun;WANG Yu-jiang;LIU Fu-xiu;HUANG Yu-yu;MAO Xi-jun(School of Mechanical Engineering, Guangxi University, Nanning 530004, China;Guangxi University of Science and Technology, Guangxi Key Laboratory of Automobile Components and Vehicle Technology, Liuzhou 545006, China)

机构地区：[1]广西大学机械工程学院,广西南宁530004 [2]广西科技大学广西汽车零部件与整车技术重点实验室,广西柳州545006

出　　处：《广西大学学报（自然科学版）》2020年第6期1351-1358,共8页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51465001,51065002);广西自然科学基金资助项目(2018GXNSFAA294122)。

摘　　要：为进一步研究尾水管涡作用下水轮机转轮叶片的动力学特性,以水轮机转轮叶片为研究对象,根据水轮机转轮叶片准三元反设计的特点,应用有限单元法建立尾水管涡作用下转轮叶片的动水压力的数学模型,并对其分布规律进行了研究。首先依据水轮机转轮叶片准三元理论,建立转轮叶片的准三元有限元模型。然后根据布拉修斯定理和计算流体力学数值模拟的压力分布,建立反映尾水管涡作用下转轮叶片动水压力与水头、流量、转速等参数之间内在关系的数学模型。最后通过实例分析验证了数学模型的可行性,并揭示尾水管涡作用下动水压力暂态过程变化机理,研究发现:尾水管涡作用下的转轮叶片动水压力产生部分负荷的运行工况,且动水压力自上冠处到下环处逐渐增大,动水压力最大值出现在转轮叶片下环处靠近出水边的位置。In order to further study the dynamic characteristics of turbine runner blades under vortex rope in draft tube,a turbine runner blade under hydraulic excitation was taken as the object of study and the mathematical hydrodynamic pressure model of a turbine runner blade under the vortex rope in draft tube was established using a quasi-three dimensional finite element model.The regularity of the distribution of the hydrodynamic pressure was then investigated.First,the quasi-three dimensional finite element model of a runner blade was established using the quasi-three dimensional theory.According to Blasius theorem and pressure distribution from CFD numerical simulation,the mathematical pressure model of a node under the vortex rope in draft tube was established.Based on the pressure model of a node,the mathematical hydrodynamic pressure model for any position of a runner blade was obtained.The internal relationship between the hydrodynamic pressure and its hydraulic parameters and the structural parameters of the blade was revealed.The results show that the hydrodynamic pressure frequency is related to the rotating speed and the water head.The hydrodynamic pressure amplitude is not only related to hydraulic parameters such as the rotating speed,the water head and the discharge,but also related to the runner cone depth and position coordinates.Finally,the feasibility of the mathematical model was verified by an example analysis,and the mechanism of hydrodynamic pressure of the transient process vortex rope in draft tube was revealed.It is found that the hydrodynamic pressure under the vortex rope in draft tube generates partial load,the hydrodynamic pressure increases gradually from the upper crown to the lower ring,and the maximum hydrodynamic pressure appears at the lower ring of the runner blade near the outlet water edge.

关 键 词：转轮叶片 尾水管涡 动水压力 准三元有限元法 数学模型 

分 类 号：TH212[机械工程—机械制造及自动化]