Abstract：In order to investigate flow separations at partload conditions in centrifugal pumps, twodimensional laser doppler velocimetry was successfully applied to a low specific speed radial diffuser pump to precisely measure unsteady flow fields at four partload conditions (0.75Qd, 0.50Qd, 0.40Qd and 0.30Qd) in the impeller. Based on measurements, the phaseaveraged velocity field and turbulence intensity field were obtained for each measuring point. The analysis of the measurements shows that there is no flow separation at 0.75Qd. However, a twochannel flow separation was observed in the impeller at 0.50Qd, 0.40Qd and 0.30Qd: the amounts of flow separation were quite different between two adjacent flow channels. However, the flow separations exhibit a periodicity of 120°, possibly due to the blade number ratio between impeller blades and diffuser vanes (6∶9). Furthermore, the velocity components and turbulence intensity were analyzed and compared among all four operating points. The results show that turbulence intensity increases as flow rate decreases. The highest turbulence intensity near the impeller outlet is 0.06 (based on u2) at 0.75Qd, and the highest one reaches about 0.12-0.14 at operating points 0.50Qd, 0.40Qd and 0.30Qd.
冯建军, 武桦, 罗兴锜, 卢金玲. 基于LDV的离心泵小流量工况内流场测量[J]. 排灌机械工程学报, 2013, 31(2): 109-112.
FENG Jian-Jun, WU Hua, LUO Xing-Qi, LU Jin-Ling. Measurements of internal flow in centrifugal pump at partload conditions based on LDV. Journal of Drainage and Irrigation Machinery Engin, 2013, 31(2): 109-112.
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