Numerical analysis of propeller-excited plate vibrations

Abstract

Intense vibrations excited by a propeller worsen the structural reliability of a ship. In this study, a ship hull is modeled as a simple rectangular plate to study propeller excitation vibrations. The interaction between a rectangular plate and propeller is studied, considering the fluid–structure interaction. The turbulence in the flow field is modeled by detached eddy simulations. The results show that in the propeller wake, the pressure fluctuations corresponding to the blade passing frequency (BPF) of the propeller are dominant. In the flow field near the plate, the pressure fluctuations corresponding to the natural frequencies of the plate are dominant. The plate vibrations under a propeller exciting force contain vibrations corresponding to the BPF of the propeller and natural frequencies of the plate. The vibrations of the plate can be divided into vibrations caused by propeller rotation and natural vibrations. The excitation force from the propeller changes the mode shapes of the plate. The vibrations excited by the propeller wake decrease as the distance between the propeller and the plate increases.