PIV orthogonal measurement for internal flow pattern within centrifugal pump impeller
Zhou Zhengfu1, Chen Songshan2, He Zhongning1
1.College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225009, China; 2.School of Energy and Power Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China
Abstract：According to orthogonal test requirements, nine low specific speed centrifugal impellers with deviated splitter vanes were designed and manufactured. The orthogonal factors are the splitter vane suction diameter(D′), the inlet deviated angle(θ1)and the outlet deviated angle(θ2). Each factor takes 3 levels. Under the design speed(1 250 r/min), the internal dynamic flow patterns inside each impeller have been measured using PIV system under 4 different operating modes. The characteristics and the distribution pattern of the relative velocity vector field in the impeller were revealed. The results show that the flow in the impeller is asymmetric and non-uniform. Specifically, relative flow velocity near the suction surface is higher than that near the pressure surface. The relative velocity near the suction surface is increasing along the forward direction, while that near the pressure surface is decreasing. There is a high-velocity zone at the front suction surface(inlet)and a low-speed one at the front pressure surface(inlet). The deviated splitter vanes shapes and locations have a significant influence on the flow field inside the impeller. There are large differences between different schemes. When D′ is moderate, θ1 is bigger and θ2 is suitable, the flow field inside the impeller is better. The law revealed in the overall characteristic test is also similar with the PIV test.
[1]Kurokawa Junichi,Matsumoto Kazunari,Matsui Jun,et al.Performances of centrifugal pumps of very low speci-fic speed[C]//Proceedings of the XIX IAHR Sympo-sium:Section on Hydraulic Machinery and Cavitation.Singapore:[s.n.],1998.[2]关醒凡.现代泵技术手册[M].北京:宇航出版社,1995.[3]王乐勤,朱祖超,汪希萱.低比转速两级复合叶轮高速离心泵的研制[J].浙江大学学报:自然科学版,1997,31(5):688-694. Wang Leqin, Zhu Zuchao, Wang Xixuan.Development on low-specific-speed high-speed centrifugal pump with two-stage complex impeller[J].Journal of Zhejiang University:Natural Science,1997,31(5):688-694.(in Chinese)[4]齐学义,倪永燕.复合式离心泵叶轮短叶片偏置设计分析[J].甘肃工业大学学报,2003,29(4):60-63. Qi Xueyi, Ni Yongyan.Analysis of impeller design of compound centrifugal pumps with offset short blades[J].Journal of Gansu University of Technology,2003,29(4):60-63.(in Chinese)[5]袁寿其,张玉臻.离心泵分流叶片偏置设计的试验研究[J].农业机械学报,1995,26(4):79-83. Yuan Shouqi, Zhang Yuzhen.Tests on centrifugal pump with deviated splitting vanes[J].Transactions of the Chinese Society for Agricultural Machinery,1995,26(4):79-83.(in Chinese)[6]Westerweel J. Fundamentals of digital particle image velocimetry[J].Measurement Science and Technology,1997,8(12):1379-1392.[7]Wernet Mark P.Application of DPIV to study both steady state and transient turbomachinery flows[J].Optics & Laser Technology,2000,32(7):497-525.[8]周正富,陈松山,耿卫明,等.3叶片离心泵内流场的PIV测量[J].扬州大学学报:自然科学版,2006,9(3):72-75. Zhou Zhengfu, Chen Songshan, Geng Weiming, et al.Floating field measurement with PIV in centrifugal impeller of three-blade[J].Journal of Yangzhou University:Natural Science Edition,2006,9(3):72-75.(in Chinese)[9]杨华,刘超,汤方平.离心泵有盖板叶轮内部流场的PIV测量[J].农业机械学报,2003,34(2):27-29. Yang Hua, Liu Chao, Tang Fangping.PIV measurement of flow fields inside a shrouded impeller[J].Transactions of the Chinese Society for Agricultural Machinery,2003,34(2):27-29.(in Chinese)[10]陈松山,周正富,葛强,等.长短叶片离心泵正交试验研究[J].扬州大学学报:自然科学版,2005,8(4):45-48. Chen Songshan, Zhou Zhengfu, Ge Qiang, et al.Ortho-gonal experimental study on centrifugal pump with deviated splitter vanes[J].Journal of Yangzhou University:Natural Science Edition,2005,8(4):45-48.(in Chinese)
