Internal Unsteady Flow Induced Vibration in Centrifugal Pump

Abstract

Centrifugal pump is an important installation for fluid delivery. The research on the unsteady flow in centrifugal pump is very meaningful to reducing vibration. The methods of numerical simulation were discussed. The unsteady pressure field was simulated by using Sliding Mesh (SM) model provided by Fluent. The time domain data for pressure were obtained at the monitoring points, and they were translated to frequency domain data by using FFT. The results show that the static pressure at the impeller outlet increases along the direction of impeller rotation from the position near the volute tongue. The pressure disturbance is relatively large near the volute tongue. The pressure disturbance at the impeller inlet is smaller than that at the impeller outlet. The volute tongue plays a key role in the flow induced vibration. The position, where the blade is in closest proximity to the head of volute tongue, is the turning point in the pressure fluctuation cycle. The maximum peak value of pressure fluctuation appears at 145Hz, which is the blade frequency. Other pressure peaks are evident at multiples of the blade frequency. Also the pressure amplitude decreases with increasing frequency.