Multi-scale fluid-induced vibration characteristics of centrifugal pump based on fluid–structure interaction method

Fluid-induced vibration (FIV) is a key factor in low-frequency vibration of centrifugal pumps. This study focuses on a vertical low-specific-speed centrifugal pump and adopts an excitation source-transmission path-vibration response framework to better predict the FIV. The inner characteristics of the entire flow field were investigated based on fluid–structure interaction. The relative errors between the experimental and simulated results are 2.26% and 1.01% for efficiency and head at design point, respectively. In addition, the fluid-induced excitation and vibration characteristics of the centrifugal pump were further explored from the point of view of vibration transmission in pump unit. The results indicate that the blade passing frequency fBPF is the primary frequency governing the pressure pulsations and vibration characteristics of the centrifugal pump. The total vibration acceleration levels (TVALs) at various locations of the centrifugal pump increase with the flow rate. In the low-frequency range, the TVAL at the vibration absorber reaches its maximum at 108 dB, while the TVAL at the inlet flange is the lowest at 88 dB.