Analysis of flow in vane diffuser and its optimization based on CFD method
Zhang Renhui1,2, Guo Rong1, Yang Junhu1,2, Li Rennian1,2
1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2.Key Laboratory of Fluid Machinery and Systems, Gansu Province, Lanzhou, Gansu 730050, China
Abstract：Concerning limitations in the traditional design approach for vane diffuser of centrifugal pump, a relationship between hydraulic performance and vane wrap angle is obtained by means of CFD analysis to achieve the best design of the diffuser. In the optimization, the pump efficiency and head are taken as the optimization objective functions, while the meridian shape, leading and trailing edges vane angles remain unchanged. The results show that the wrap angle has an important influence on the internal flow structure and hydraulic performance of the pump and there is an optimum wrap angle for the best efficiency when the rest geometrical parameters of the diffuser keep unchanged. The high pressure zone on the blade pressure side moves from the inlet to the outlet gradually with increasing of wrap angle, and the blade becomes "post-loaded" from "front-loaded". As the vane angle changes greatly in the vane forepart, there is a flow separation zone starting from the middle of the vane chord; fortunately, the separation zone shrinks and is located at near the vane outlet with increasing wrap angle. Note that the blocking aggravates at the vane inlet and subsequently the inlet velocity increases gradually with increasing wrap angle. The relations between flow structure and wrap angle have been revealed and some theoretical basis has been established for the optimization of vane diffuser.
张人会,, 郭荣, 杨军虎,, 李仁年,. 基于CFD的空间导叶内部流场分析及优化设计[J]. 排灌机械工程学报, 2015, 33(9): 762-767.
Zhang Renhui,, Guo Rong, Yang Junhu,, Li Rennian,. Analysis of flow in vane diffuser and its optimization based on CFD method. Journal of Drainage and Irrigation Machinery Engin, 2015, 33(9): 762-767.
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