离心式水力空化发生器空化空蚀机制试验研究  

Experiment on cavitation erosion mechanism of centrifugal hydraulic cavitation generator

作　　者：王健[1] 刘厚林[2] Matevz Dular Wang Jian Liu Houlin Matevz Dular(School of Shipping and Mechatronic Engineering, Taizhou University, Taizhou 225300, China Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013, China Laboratory for Water and Turbine Machines, Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana 1000, Slovenia)

机构地区：[1]泰州学院船舶与机电工程学院,泰州225300 [2]江苏大学流体机械及工程技术研究中心,镇江212013 [3]Laboratory for Water and Turbine Machines,Faculty of Mechanical Engineering,University of Ljubljana,Ljubljana 1000,Slovenia

出　　处：《农业工程学报》2017年第14期49-55,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金青年基金项目(51609164);江苏省自然科学基金青年基金项目(BK20160574);泰州学院博士/教授项目(QD2013002)

摘　　要：该文对一台转子-定子型离心式水力空化发生器的性能进行了系统的试验研究,以寻求其空化生成机制并与空蚀分布之间的关系。可视化试验结果表明空化发生器内存在楔形槽空化、转子叶齿和定子叶齿前缘空化。通过水听器测量了空化发生器蜗壳侧面位置的压力脉动情况,在相同转速下压力脉动随着流量的增加而增大,压力脉动周期不变;在相同流量下压力脉动随着转速的增加而增大,周期减小:50 Hz时压力幅值为30 Hz时的2.5倍,周期缩短0.001 s。油墨法试验结果显示空蚀主要发生在转子叶齿尾端和中部,定子叶齿前缘空泡附着部分及尾端。楔形槽空化是造成破坏的主要原因,因其空化强度最高且空泡溃灭行为离固壁表面最近。该研究可为离心式空化发生器的研发提供参考。The performance of a rotor-stator centrifugal cavitation generator was experimentally studied, aiming at investigating the correlation between its cavitation mechanism and damage distribution. The generator was modified from a centrifugal pump, including a cut impeller, a volute, a rotor and a stator. The rotor and stator consist of 12 teeth each, whereas the stator has wedge grooves on each tooth. Therefore, as the rotor spins, there are 12 nozzles when the rotor tooth overlaps the stator tooth. The experiments were conducted in a closed-loop test rig in the Laboratory for Water and Turbine Machines of University of Ljubljana, Slovenia. The cavitation generator was also used as a flow driver in the test. In order to study the cavitation mechanism, an observation window was mounted on the side of the generator volute. The cavitation evolution was recorded via a high speed camera accordingly. Based on the visualization tests, it is found that there are 3 kinds of cavitation generating mechanisms. One is produced in nozzle tubes formed by the interaction movement of the rotor and stator. The other two are caused by the high speed rotation of the rotor. One happens on the leading edge of the stator tooth as the rotor moves towards it. At the same time, the rotor itself generates bubbles on the leading edge of the tooth. Hence, in one rotor-stator teeth interlacing period, the cavitation generated on the leading edge of the stator （nozzle cavitation and rotating-induced cavitation） has 2 circulations. For detecting the cavitation intensity, the pressure pulsation between the rotor and volute was measured by a hydrophone under different operating conditions. The results show that the pressure pulsation increases as the flow rate increases while keeping the rotating speed constant, but the pressure pulsation cycle remains the same. As the driving frequency is 50 Hz, the pressure amplitudes under 18 and 31.4 m3/h are 1.0×105 and 1.5×105 Pa, respectively, while the cycle is approximately 0.002 s. Additionally, rega

关 键 词：水力 离心泵 空化 空化发生器 空蚀 可视化试验 

分 类 号：TV131.63[水利工程—水力学及河流动力学]