Inlet pre-whirl for contrarotating axial-flow water-jet pump
HUANG Zhenjie1, PAN Zhongyong 1, SHEN Zhanhao2, PAN Xiwei3
1.National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.School of Jingjiang, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 3.Mechanics Institute, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
Abstract：To study the reason why water-jet propulsion pump efficiency at a small flow rate decreased rapidly, the computational fluid dynamics method was applied to the numerical simulation of water-jet pump at a small flow rate. Based on different flow rates and rotation rate control methods,the emergence and development of inlet pre-whirl was studied and the relation between the rotation rate and the inlet pre-whirl was analyzed. The results show that in the working condition, circumferential component of the absolute velocity of the front inlet impeller is close to 0 and changes hardly following the flow channel, and the inlet pre-whirl can be neglected. In the 0.8 Qd working condition, the increase along with the change of flow channel is very small, there is a small pre-whirl only at the rim. At the beginning of 0.6 Qd, the change in inlet pre-whirl becomes obvious, the lower the flow is, the greater the change is. Under the low flow, reducing the front impeller speed can effectively improve the inlet pre-whirl and also can improve the efficiency of the pump. Regulating the impeller speed can effectively improve the inner flow of the pump. The results are of important guiding significance to the inlet pre-whirl analysis of other specific speed water-jet propulsion pumps.
倪永燕,刘为民.泵喷水推进器研究进展[J].船海工程,2013,42(5):1-5. NI Yongyan, LIU Weimin. Research progress on waterjet pump[J].Ship & ocean engineering,2013,42(5):1-5.(in Chinese)PARHA W G,JANGA J H,CHUNB H,et a1.Numerical flow and performance analysis of water-jet propulsion system [J].Ocean engineering,2005,32:1740-1761.潘中永,吴涛涛.斜流式泵喷水推进器内部流动不稳定性分析[J].华中科技大学学报(自然科学版),2012,40(9): 118-121. PAN Zhongyong, WU Taotao. Instability analysis of internal flow in mixed-flow pump water-jet propulsion[J].Journal of Huazhong University of Science and Technology(natural science edition),2012,40(9): 118-121.(in Chinese)GALINDO J,SERRANO J R,MARGOT X,et al.Potential of flow pre-whirl at the compressor inlet of automotive engine turbochargers to enlarge surge margin and overcome packaging limitations [J].International journal of heat and fluid flow,2007,28(3):374-387.施卫东,李辉,陆伟刚,等.进口预旋对低比速离心泵无过载性能的影响[J].农业机械学报,2013,42(5):50-55. SHI Weidong,LI Hui,LU Weigang,et al.Effect of prewhirl flow on non-overload performance of low specific speed centrifugal pumps[J]. Transactions of the CSAM,2013,42(5):50-55.(in Chinese)刘承江,王永生,张志宏,等.喷水推进器推力的 CFD计算方法研究[J].计算力学学报,2008,25(6):927-931. LIU Chengjiang,WANG Yongsheng,ZHANG Zhihong, et al.Research on computational methods of water-jet thrust using CFD[J].Chinese journal of computational mechanics,2008,25(6):927-931.(in Chinese)FURUKAWA A,SHIGEMITSU T,WATANABE S. Performance test and flow measurement of contra-rotating axial flowpump[J].Journal of thermal science,2007,16(1):7-13.李辉.基于CFD方法的全方向推进器水动力性能研究[D].哈尔滨:哈尔滨工程大学,2009.陈伟,陆林广,王刚,等.轴流泵运行工况对叶轮室进口预旋的影响[J].水力发电学报,2012,31(1): 213-219. CHEN Wei,LU Linguang,WANG Gang,et al. Influence of axial-flow pump operating condition on the pre-swirl at impeller chamber inlet[J]. Journal of hydroelectric engineering,2012,31(1): 213-219.(in Chinese)PARK W G, JIN H J, CHUN H H, et al. Numerical flow and performance analysis of waterjet propulsion system[J]. Journal of the society of naval architects of Korea, 2005, 32(14):1740-1761.申占浩,潘中永,李红,等.基于CFD的对旋轴流式喷水推进泵转速控制方法[J].排灌机械工程学报,2014, 32(11): 931-936. SHEN Zhanhao, PAN Zhongyong, LI Hong, et al.CFD-based rotational speed control method for contra-rotating axial-flow water-jet pump[J].Journal of drainage and irrigation machinery engineering,2014,32(11): 931-936.(in Chinese)