Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

作     者：Demin LIU Xiaobing LIU Yongzhi ZHAO 

作者机构：Key Laboratory of Fluid and Power Machinery of Ministry of Education Xihua University Dongfang Electric Machinery Co. Ltd 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2017年第30卷第4期

页      面：854-865页

核心收录：

学科分类：080703[工学-动力机械及工程] 080704[工学-流体机械及工程] 0817[工学-化学工程与技术] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 0811[工学-控制科学与工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Supported by National Natural Science Foundation of China(Grant No.51279172) Open Research Subject of Key Laboratory of Fluid Machinery of Ministry of Education,Xihua University,China(Grant No.szjj2015-022) Key Laboratory of Natural Science Fund of Education Department of Sichuan Province,China(Grant No.080704) 

主　　题：Inter-blade vortex Francis turbine Highspeed photography 

摘      要：The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating con- ditions. However, the causes and the mechanism of inter- blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter- blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and theblade angle on the leading edge of the runner at deep part load operating conditions.