Controllable Pitch Tunnel Thruster Design And Performances Simulation

As an auxiliary propulsion unit, tunnel thrusters substantially improve the controllability and safety of a ship at low speed, enable it to keep a certain course with the help of rudders. More and more attention is paid to these devices by shipbuilders, tunnel thrusters have been applied on majorships widely right now.Based on the research program, a tunnel thruster is designed and the hydrodynamic performance of it is simulated. The Master's thesis research " Controllable pitch tunnel thruster design and performances simulation" is conducted.Chapter one:Background and significance of design and study of tunnel thrusters are described; development and key technology of tunnel thrusters are introduced. Finally research significance and framework of the thesis are proposed.Chapter two:After analyzing the working principle of tunnel thrusters and controllable-pitch propellers, the structural design of controllable-pitch tunnel thruster is proposed based on summarizing the tunnel thrusters'structure.Chapter three:Based on the structural design and function demand of controllable-pitch tunnel thruster, structural design of tunnel thruster's key parts is carried out with repairable design process.Chapter four:The propeller design chart and propeller vortex lattice lifting line theory are applied respectively in the propeller design of tunnel thruster and the results agreed well with each other; propeller efficiency at different number of blades, different diameter of blades and different power of engine is analyzed based on propeller vortex lattice lifting line theory.Chapter five:Simulation model of tunnel thruster is built based on RANS of CFD and the mesh of compute field is generated with hybrid grid method by GAMBIT, finally k-s turbulence model is used to simulate the hydrodynamics characteristic in tunnel thruster.Chapter six:Hydrodynamics characteristic in tunnel thruster is described through simulation, compared with experimental data, the numerical results show good agreement; by analyzing hydrodynamics characteristic in tunnel thruster under design condition and transitional running condition, performance of tunnel thruster is predicted.Chapter seven:The main content of the dissertation research is summarized, and the prospect of tunnel thrusters is presented.