Analysis of Vibration Noise and Transmission Characteristics of Flow-induced Rudder

In order to study the flow-induced vibration and transmission characters and the influence of rudder on the flow field, a small-scale Suboff model which consists of the rudder and the connected part of the hull is established in this paper. Based on the structural FEM, the vibration transfer function of the rudder-hull is analyzed. And the flow field is calculated by CFD method, which the one-way fluid-structure coupling calculation is carried out by STRACCM+ and ABAQUS, and the unsteady flow field part is solved by the DES turbulence model. The trace distribution of the fluid micro-clusters near the rudder and the hull is given by adding streamlines. The vibration transfer function results show that the vibration of the rudder blade has attenuated when it is transmitted to the rudder root and the hull structure. The fluid traces indicate the presence of eddy currents near the root and seam of the rudder. As speed changes, fluid elements are accompanied by bending and rotation, which causes interference. Therefore, when the rudder is not operating, the main factor that affects the concealment related to the rudder is the flow field and the structural characteristics of the rudder. Under the speed condition of 8kn, the simulation results also show that the structural sound radiation component of the rudder is mainly near the natural frequency of the rudder. This article does not consider the rudder working conditions and the vibration and noise of the rudder power unit, steering mechanism and other equipment.