%A Chen Bin,, Zhang Hua, Shi Weidong, Ba Yanqing, Dong MianjieŠĪ %T PIV experimental study on flow field in submersible sewage pump with low specific speed %0 Journal Article %D 2013 %J Journal of Drainage and Irrigation Machinery Engin %R 10.3969/j.issn.1674-8530.2013.07.005 %P 575-579 %V 31 %N 7 %U {http://zzs.ujs.edu.cn/pgjx/CN/abstract/article_1507.shtml} %8 2013-07-25 %X After the state-of-the-art investigations into low specific speed submersible sewage pumps were reviewed, it was found that the studies mainly focused on numerical calculations, while there is a lack of internal flow field visualization investigations. Therefore, the internal flow field in a submersible sewage pump with specific speed of 60 was measured by means of a 2D-PIV under different operating conditions to reveal the flow structure and development in the impeller from the inlet to the outlet. The pump original structure was modified with a transparent plexiglas to replace the conventional metal material, and the hollow glass spheres were severed as seeding particles for the PIV measurements. The experimental results show that the relative velocity on the blade suction surface near the blade inlet is greater than that on the blade pressure surface while this velocity profile is reverse near the blade outlet due to the Coriolis effect. The velocity gradient at the blade inlet is the largest, and the jet-wake phenomenon at the blade outlet is the most obvious at high flow rates. A flow separation was observed on the blade pressure surface at various flow rates; meanwhile, it moved towards the blade outlet and gradually developed into a vortex rotating in the direction of opposite blade rotation with decreasing flow rate. At 0.2Qd operating point, the vortex is in the center of flow passage at the blade outlet and blocks most of the passage.ŠĪ