Structural dynamic characteristics analysis of a mixed-flow pump based on fluid–structure coupling

Abstract

Mixed flow pump has received widespread applications in various perspectives, therefore, enhancing the operational stability is crucial to pump design and applications. To address this phenomenon, the present work explores the efficacy of fluid–structure coupling approach to analyze the vibration characteristics and fluid-excited dynamic properties of mixed flow pump. In this study, ANSYS Workbench is employed for static and modal analysis of the pump, while dynamic analysis is performed based on the outcomes of unsteady fluid analysis. The findings, however, revealed that the guide vane region registered the largest stress and most violent deformation in the entire pump. Compared with other parts of the pump body, the thickness of the guide vane is relatively small, and at the same time, considering the influence of periodic changes in the pressure in the flow channel, its strength should be considered in the design while preventing fatigue damage, and the material and processing method should be selected to meet the requirements. Meanwhile, at the entrance of the guide vane, the impeller rotation attained supremacy in the fluid pressure pulsation, and at the same time, a low-frequency pulsation caused by the vortex structure in the guide vane emanate in the channel. It is worth noticing that both blade deformation and equivalent stress depicted periodic variations. Interestingly, the blades recorded the modest values for both maximum average equivalent stress and maximum average total deformation at the design operating points. However, at over-load operating points, the blades registered their maximum values. The conclusions of this study could lay a foundation for conducting stability analysis on mixed-flow pumps and optimizing the design of the guide vane.