Experimental and Numerical Investigations of Vibration Characteristics Induced by Pressure Fluctuations in a Parallel Operating Pumping System.

Parallel pumping systems may operate with excessive vibrations as a result of complex hydraulic excitation sources. To remove excessive vibrations, it is essential to understand the relationships between inner hydraulic excitations and outer vibration characteristics. In this investigation, experiments that included pressure and vibration measurements were performed in a parallel operating pumping system. A computational method was evaluated to determine its ability to reproduce the experimental results. The experimental results show that a large-amplitude vibration may occur under two specific conditions. One is when intrinsic single frequencies in pumps fall into the range of the broadband frequencies. The other is the beat phenomenon, which can occur if the blade passing frequencies (BPFs) from different pumps have a slight difference. The resonance condition is most likely satisfied on the floor slab of the pump house because the natural frequencies of the floor slab are relatively close to the BPF. The computational strategy is proven to be appropriate for resonance checks and risk assessment of high-level vibrations at the design stage. [ABSTRACT FROM AUTHOR]