The Research On Special Rudder’s Hydrodynamic Performance And Numerical Simulation Of Propeller-rudder System

The maneuverability of the ship is mainly impacted by rudder. A ship’s main dimension is determined on its stability and desire speed, maneuverability is considered after the ship had been built. But, in this way, only certain requirements of the maneuverability can be met. The study of rudder’s hydrodynamic performance has become the key method to improve the ship’s maneuverability. There are three methods to advance the study of rudder’s hydrodynamic performance:experimental research, theoretical analysis and numerical simulation.In this paper, the mesh-generator ICEM-CFD, is used to generate high-quality hybrid meshes, including both hexahedral mesh and tetrahedral mesh, the CFD (computational fluid dynamics) software Fluent is adapted to simulate the hydrodynamic performance of the rudders. In addition, Multi-Reference Frame (MRF) Model and Sliding Mesh Model are respectively applied to simulate the rotation of the propeller, and the results of the calculation are compared carefully. Finally, the Sliding Mesh Model was chosen to simulate the hydrodynamic performance of propeller-rudder system in a uniform flow.The thesis simulates the hydrodynamic performance of three kinds of representative special rudders:Jet rudder Shilling rudder and Built-up rudder.The results of the calculation reveal a preliminary understanding of the principle how special rudders can improve the lift performance, and the advantage and disadvantage of each rudder can be seen easily. My work can provide a reference for further research.What’s more, both the rudder in open water and the rudder after propeller are simulated in the thesis, and wake characteristics of the open water performance of the rudder and propeller are analyzed. Due to the existence of the propeller wake, the velocity of the flow through the rudder surface becomes faster, leading to the change of rudder’s hydrodynamic performance. In this paper, numerical study of the propeller-rudder system provides some basis foe for making full use of the propeller wake structures to reduce energy loss and improve the rudder’s lifespan. This conclusion of this thesis can provide a reference for engineering application to some extent.