Numerical study on the flow-induced vibration of a high-pressure-jet pump on a dredger and corresponding impeller optimization

Abstract

Abstract Trailing suction hopper dredgers are usually equipped with high-pressure-jet pumps, which provide high pressure water to improve dredging efficiency. In a newly built trailing suction hopper dredger, the high-pressure-jet pump encountered serious vibration problem. In this study, unsteady Reynolds-averaged Navier-Stokes equations were solved with Shear Stress Transport k-ω turbulence model to carry out pump-pipeline matching analysis, and the causes of flow-induced vibration were discussed. The impeller was correspondingly optimized by increasing the blade number and moderately decreasing the blade inlet setting angle and wrap angle. The optimization results show that the high-pressure-jet pump works in the high-efficiency zone both for the high-speed dredging process and low-speed hopper discharging process, and the time-average value and amplitude of the hydraulic radial force drops by more than 30% under the required working condition, which effectively mitigates the flow-induced vibration.