Study on the application of vortex generator to suppress ship propeller cavitation excitation

Abstract

ABSTRACT A triangular vortex generator (VG) is used to suppress the hull vibration induced by propeller cavitation in this paper. Firstly, the numerical simulation method is used to simulate the original flow field around the ship, and the high wake area caused by the separation of the flow at the stern is analysed, which leads to serious cavitation on the propeller and induced hull vibration. Then, the effects of the installation angle and position of the VG on the wake of the ship are analysed, and the appropriate design parameters of the VG are obtained. Through the numerical simulation of cavitation on the propeller, the effects of VG on cavity shape and hull fluctuating pressure induced by cavitation are analysed. The VG can improve the non-uniformity of wake field, delay cavitation generation, and weaken the cavitation on the propeller tip area. The maximum reductions of the first, second, and third harmonics of fluctuating pressure are about −41.2%, −36.6%, and −78.5%, respectively. Finally, the vibration of each cabin of the full scale vessel is significantly reduced after the installation of the VG, especially in the cabin near the propeller. The reduction range is up to −54.5%, and a good vibration reduction effect is obtained.