1.College of Water Conservancy and Hydropower, Hohai University, Nanjing, Jiangsu 210098, China; 2.National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing, Jiangsu 210098, China; 3.Tongyu River Management Division in Yancheng, Yancheng, Jiangsu 224511, China; 4.College of Energy and Electric Engineering, Hohai University, Nanjing, Jiangsu 211100, China
Studying the modal of axial-flow pump rotor system in water and the impact of water on modal is important to ensure the efficiency, stable running of the pump and to avoid resonance. By secondly developing the ANSYS Workbench based on fluid-solid coupling theory, we compiled APDL language to couple the fluid and solid calculation equation so as to calculate the modal of axial-flow pump rotor system in air and water. The results show that when the three-dimensional modeling of structure domain was carried out before modal analysis, the hollow portion of structure cannot be simplified to solid area, which is different from flow field analysis. The existence of water makes each order natural frequency of rotor system declined. The depreciation coefficient ranges from 7.95% to 13.29% and each order depreciation coefficient does not show an obvious rule. The blade passing frequency of axial-flow pump is 15 Hz and the guide passing frequency of axial-flow pump is 25 Hz, which are much less than each order natural frequency of axial-flow pump rotor system in water, so it is less likely to generate resonance during running time.
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