ANALYSIS OF FLOW-INDUCED VIBRATION OF THE VOLUTE OF A CENTRIFUGAL PUMP BASED ON FINITE ELEMENT METHOD

摘要

During the operation of centrifugal pumps, radial hydraulic force is generated due to non-uniform flow within pumps, which is one of the main sources of the vibration of the centrifugal pump volute. In this paper, based on CFD and finite element method, it was calculated and analyzed that the volute vibration of a centrifugal pump caused by radial hydraulic force. The reason of the occurrence of radial force was analyzed, and by simplifying the theoretical formulas the force was calculated. Then the unsteady flow field of a centrifugal pump was simulated and analyzed under different running conditions by CFD method. Based on the simulation results, the radial hydraulic force of the pump was calculated. Finally, vibration response of the pump volute due to the hydraulic radial force was obtained. By analyzing the vibration response datum, vibration parameters were got such as the displacement, velocity and acceleration of vibration. It was obtained that the main vibration frequencies of the pump volute which is caused by unsteady flow are blade frequency and its harmonic frequencies. The pump volute has a minimum vibration under design flow rate condition, and it has a maximum vibration at the 1.5 times design rated flow whilst the vibration frequency is the integral multiple of the blade frequency. This study is helpful to understand the flow-induced vibration of pump volute and to improve the hydraulic design of the centrifugal pump.