To remedy the instability of internal flow in the impeller of a centrifugal pump of low specific speed at low flow rates, the impeller was redesigned to have slotted, then the flows in the pump with this kind of impeller and the original one were analyzed by using CFD codeFluent to identify effects of such blades on the internal flow and performance. It was shown that the pump head and total efficiency are a little increased at a lower flow rate as one slot was presented on every blade blades compared with the pump with the original impeller, but they are declined at a higher flow rate, suggesting the blade with one slot on it can improve the instability of internal flow in the impeller passages of centrifugal pumps of low specific speed at partial flow rates. In order to clarify influence of number of slots on the internal flow and the performance, an additional slot was made on every blade as well, and it was found that the instability of flow and efficiency are poorer against the case with one slot. It was confirmed that the slots on blades do improve the turbulence of flow in the impeller of a centrifugal pump of low specific speed at lower flow rates point in some degree, however, that number of slots will affect the performance of the pump.
Yang Minguan, Gu Haifei, Liu Dong, et al. Internal turbulent flow in centrifugal pump impeller numerical calculation and test[J]. Chinese Journal of Mechenical Engineering, 2006,42(12):180-185. (in Chinese)
Spence R,Amaral T J.Investigation into pressure pulsations in a centrifugal pump using numerical methods supported by industrial tests[J].Computers ＆ Fluids, 2008,37(6):690-704.
Cui Baoling,Zhao Rui,Zhang Yuliang, et al.The research on flow characteristics of highspeed centrifugal pump with open impeller[J]. Journal of Engineering Thermophysics,2010,31(4):601-605. (in Chinese)
Yuan Shouqi, Zhang Jinfeng,Yuan Jianping, et al. Effects of splitter blades on the law of inner flow within centrifugal pump impeller[J]. Journal of Mechanical Engineering, 2007,20(5):57-63.
Stefan Berten, Philippe Dupont, Laurent Fabre, et al. Experimental investigation of flow instabilities and rotating stall in a highenergy centrifugal pump stage[C]／／Proceedings of the ASME Fluids Engineering Division Summer Meeting, 2009: 505-513.