CFD-FEM Analysis of Flow-Induced Vibrations in Waterjet Propulsion Unit

Abstract

This paper investigates the problem of vibration in an axial flow waterjet propeller with high power density and low specific speed. Based on fluid–structure coupling vibration analysis, combined with modal analysis and ship tests, the unsteady fluid–structure coupling of a waterjet propeller is examined, and the vibration characteristics of the propeller under different speed conditions are studied. The results show that the vibrations of the waterjet propeller mainly come from the frequency response of the rotor and the structural resonance response. The frequency distribution characteristics and amplitude intensity are observed to increase with increasing rotation speed. The variations in the propeller vibration characteristics, with respect to parameter changes, are analyzed at different gap spacings between the rotor and stator, allowing the variation law of vibration intensity with rotor stator spacing to be obtained.

Keywords

• waterjet propulsion
• fluid excitation
• pressure fluctuation
• frequency domain analysis
• fluid–structure interaction