Abstract：In order to study the fatigue characteristics of an impeller under the pressure fluctuation in a flow field during its operation, the flow field in the first stage of the LVS 3-9 vertical multistage pump was simulated by software CFX on the multiphysics platformAnsys Workbench according to the similarity of flow and structure among various stages, then the characteristics of pressure fluctuation in the impeller and diffuser have been obtained. The fluid static pressure obtained by CFD was applied on the structural model of impeller, and the stress and deformation of the structure were analyzed under such a load based on the oneway coupling method for fluidstructure interaction (FSI) in Ansys. Considering the feature of pressure on bladed the fatigue limit of the welded impeller was estimated by best fitting the S-N curve of the impeller material obtained based on the least square method. Eventually, the fatigue strength of the impeller structure was assessed by means of the modified Goodman fatigue limit diagram. The results show that the stress in the impeller structure decreases steadily from the inlet to the outlet, the deformation, however, increases gradually and a peak one can be found at the impeller outlet. At the same radial position, the obvious stress concentration is located at the welding zones between the shroud and blades. The impeller structure exhibits a bending deformation, which is towards to the impeller eye, all in the axial direction. The fatigue strength of the impeller with two welding spots is lower than the fatigue limit at all the flow rates and the mean stress and stress fluctuating amplitude are the highest at the low flow rate.
王洋, 王维军, 王洪玉, 叶道星, 李贵东. 冲压焊接多级离心泵叶轮的疲劳强度[J]. 排灌机械工程学报, 2013, 31(3): 215-219.
WANG Yang, WANG Wei-Jun, WANG Hong-Yu, YE Dao-Xing, LI Gui-Dong. Fatigue strength on stamped and welded impeller in multistage centrifugal pump. Journal of Drainage and Irrigation Machinery Engin, 2013, 31(3): 215-219.
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