Abstract:In order to improve cavitation performance of a centrifugal pump, a slot is made through each blade near its leading edge in a low specific speed centrifugal pump. Considering three parameters defining a slot, and six hydraulic models are designed. Cavitating flows in these pump models are simulated in CFX by means of steady Reynolds average N-S equations, a cavitation model, which is based on the Rayleigh-Plesset equation, and the RNG k-ε turbulence model. The simulated results show that slots on blade near their leading edge can improve cavitation performance, especially, in the second model the pump cavitation performance is improved more obviously, namely the hydraulic efficiency is increased to 76.46% from 71.56%, and the NPSH is decreased to 3.910 m from 4.447 m, resulting in a 12.1% reduction. At the duty flow rate, the energy inside the flow channels between the two blades is more uniformly distributed, while the head remains changed a little. The simulated results may have some referential value for investigating features of internal flow in a low specific speed centrifugal pump and its performance improvement.
王洋, 谢山峰, 王维军. 开缝叶片低比转数离心泵空化性能的数值模拟[J]. 排灌机械工程学报, 2016, 34(3): 210-215.
WANG Yang, XIE Shanfeng, WANG Weijun. Numerical simulation of cavitation performance of low specific speed centrifugal pump with slotted blades. Journal of Drainage and Irrigation Machinery Engin, 2016, 34(3): 210-215.
[1]叶道星.采用开缝叶片对离心泵性能影响的研究[D].镇江:江苏大学,2013.[2]邢纲.开缝叶片离心叶轮内流场的数值研究[D].重庆:重庆大学,2008.[3]罗先武,张瑶,彭俊奇,等.叶轮进口几何参数对离心泵空化性能的影响[J].清华大学学报(自然科学版),2008,48(5):836-839. LUO Xianwu, ZHANG Yao, PENG Junqi, et al. Effect of impeller inlet geometry on centrifugal pump cavitation performance[J]. Journal of Tsinghua University(science & technology), 2008,48(5):836-839.(in Chinese)[4]刘厚林,刘东喜,王勇,等.泵空化流数值计算研究现状及展望[J].流体机械,2011,39(9):38-44. LIU Houling, LIU Dongxi,WANG Yong, et al. Numerical research status and prospects of cavitating flow in a pump[J].Fluid machinery, 2011,39(9):38-44.(in Chinese)[5]李军,刘立军,丰镇平.数值模拟两相空化流动的新模型和算法[J].计算物理,2006,23(5):530-536. LI Jun, LIU Lijun, FENG Zhenping. A model for two-phase cavitation flows[J].Chinese journal of computational physics, 2006,23(5):530-536.(in Chinese)[6]BRENNEN C E. Cavitation and bubble dynamics[M]. London: Oxford University Press, 1994.[7]TIM Colonius, KUNIHIKO Taora. A fast immersed boundary method using a nullspace approach and multi-domain far-field boundary conditions[J]. Computer methods in applied mechanics and engineering,2008,197:2131-2146.[8]WANG Weijun, WANG Yang. Applicability of eddy viscosity turbulence models in low specific speed centrifugal pump[C]//Proceedings of the IOP Conference. Ser.: Earth Environ. Sci., 2012(15):062013.[9]关醒凡.现代泵理论与设计[M].北京:中国宇航出版社,2011.[10]FERZIGER J H, PERIC M. Computational methods for fluid dynamics[M]. Berlin: Springer, 1996.[11]赖喜德,廖功磊,曾维国.离心泵的空化流数值模拟与空化余量预测[J].西华大学学报(自然科学版),2013,32(2):29-32. LAI Xide, LIAO Gonglei, ZENG Weiguo. Numerical simulation of cavitating flow and prediction for NPSHRin centrifugal pumps[J]. Journal of Xihua University(natural science), 2013,32(2):29-32.(in Chinese)[12]袁寿其.低比速离心泵理论与设计[M].北京:机械工业出版社,1997.[13]朱荣生,付强,李维斌.低比转数离心泵叶轮内空化两相流三维数值模拟[J].农业机械学报,2006,37(5):75-79. ZHU Rongsheng, FU Qiang, LI Weibin. Numerical simulation of 3D two-phase cavitation flow in impeller of the low specific speed centrifugal pump[J]. Transactions of the CSAM, 2006,37(5):75-79.(in Chinese)[14]潘中永,倪永艳,汤跃,等.离心泵空化余量计算与预测[J].农业机械学报,2008,39(12):206-209. PAN Zhongyong, NI Yongyan, TANG Yue, et al. Simulation and prediction for NPSHR in centrifugal pumps [J].Transactions of the CSAM, 2008, 39(12): 206-209.(in Chinese)[15]MILAN Sedlarl, OLDRICH Sputa, MARTIN Komarek. CFD analysis of cavitation phenomena in mixed-flow pump[J]. International journal of fluid machinery and systems,2012,5(1):18-29.