Abstract:Based on the whole and nonwhole flow domain methods, the influence of flow domain on the numerical results in centrifugal pumps was investigated by calculating threedimensional steady incompressible turbulent flows. The standard k-ε turbulence model and virtual block technology were also adopted. The internal flow fields and hydraulic performance of five centrifugal pumps with different specific speeds were calculated at the design conditions. Also, the hydraulic performance obtained was compared with the test. It is observed that the influence of flow domain is remarkable. The whole flow domain method shows a higher accuracy rather than the nonwhole flow domain one, for example, the prediction accuracies in head and efficiency are improved by 1.54% and 1.67%, respectively. The static pressure distributions in the impellers obtained by the two methods are basically the same, but those in the volutes are significantly different. The velocity profile in the gap between impeller and volute is layered for the whole domain method. However, it is triangular for the nonwhole domain one. The secondary flow pattern within the crosssections of volute is not completely symmetry. It is believed that the flows in the wearingring gap and the chamber between the impeller and the pump casing, which have been considered in the whole flow domain method, affect the development of that secondary flow.
参考文献(References)[1]Anagnostopoulos J.A fast numerical method for flow analysis and blade design in centrifugal pump impellers [J]. Computers & Fluids, 2009,38(2):284-259.[2]Derakhshan S, Nourbakhsh A. Theoretical, numerical and experimental investigation of centrifugal pumps inreverse operation [J]. Experimental Thermal and Fluid Science, 2008, 32(8): 1620-1627.[3]张翔,王洋,徐小敏,等.低比转数离心泵叶轮内能量转换特性[J].农业机械学报,2011,42(7):75-81.Zhang Xiang, Wang Yang, Xu Xiaomin, et al. Energyconversion characteristic within impeller of low specific speed centrifugal pump[J]. Transactions of the Chinese Scocity for Agricultural Machinery,2011,42(7):75-81. (in Chinese)[4]施卫东,张启华,陆伟刚.新型井泵水力设计及内部流动的数值模拟[J].江苏大学学报:自然科学版,2006,27(6):528-531.Shi Weidong, Zhang Qihua, Lu Weigang. Hydraulic design of newtype deep well pump and its flow calculation [J]. Journal of Jiangsu University:Natural Science Edition,2006,27(6):528-531.(in Chinese)[5]Spence R, Amaral J. Investigation into pressure pulsations in a centrifugal pump using numerical methods supported by industrial tests[J]. Computers & Fluids,2008, 37(6): 690-704.[6]Cheah K W, Lee T S. Numerical flow simulation in acentrifugal pump at design and offdesign conditions [J].International Journal of Rotating Machinery, 2007, 31(2):101-108.[7]张金凤,袁寿其,付跃登,等.分流叶片对离心泵流场和性能影响的数值预报[J].机械工程学报,2009,45(7):131-137.Zhang Jinfeng,Yuan Shouqi,Fu Yuedeng, et al. Numerical forecast of the influence of splitter blades on the flow field and characteristics of a centrifugal pump[J]. Journal of Mechanical Engineering,2009,45(7):131-137.(in Chinese)[8]王洋,蒋其松.两段变曲率叶型离心泵设计研究[J].排灌机械工程学报,2010,28(1):25-30.Wang Yang, Jiang Qisong. Research on centrifugal pump with double curvature blade[J].Journal of Drainage and Irrigation Machinery Engineering, 2010,28(1):25-30. (in Chinese)[9]Graosas V A, Anagnostopoulos J. Flow measurements and simulation in a model centrifugal pump impeller [J]. International Journal of Fluid Mechanics Research, 2010,37(2):149-161.[10]王福军. 计算流体动力学分析——CFD软件原理与应用[M]. 北京:清华大学出版社,2004.[11]谈明高.离心泵能量性能预测的研究[D].镇江:江苏大学流体机械工程技术研究中心,2008.