| People have paid increasing attention to the shipping industry since the 21 st century.Due to the development of technology and economic growth,the development of ships also presents a trend of large-scale,high-speed and intelligent,and at the same time,the ships needs to face more complex navigation environment.In this case,all kinds of high and new technologies have been developed and applied to ships.Rim driven propulsion,also known as tip propulsion,is a new means of ship propulsion.Compared with propeller propulsion,rim driven propulsion eliminates the shaft structure by highly integrating the motor and the propulsion part,which saves the ship cabin capacity,reduces the vibration and noise of the shafting system.It can also operate stably under complex working conditions and has great application prospect.In this thesis,the purpose and significance of the research are firstly clarified,and the research of rim driven thruster and the theoretical basis of numerical simulation are briefly introduced.Then,the numerical simulation of ducted propeller is carried out to verify the computational accuracy of CFD software.This thesis analyses the principle of rim driven thruster and simplifies the complex mechanical structure before the research about hydrodynamic performance of rim driven thruster.A simplified model for the calculation of hydrodynamic performance is obtained by 3D modeling,and the prediction of the hydrodynamic performance of the rim driven thruster is completed by using the simplified model.On this basis,the method of variable parameters is used to study the influence of blade parameters on the hydrodynamic performance of thruster by adjusting the maximum blade thickness distribution,disk ratio and pitch ratio separately.In this thesis,a theoretical design method of rim driven thruster is studied by using the lift line theory.Variational method is used to construct the auxiliary function,which has the extreme value by setting the thrust or torque under the particular condition for the blade profile of the rim driven thruster with the optimum circulation distribution.In the design process,torque correction formula is introduced for the torque of the gap,and the validity of the theoretical design method is verified by numerical simulation.Finally,in order to study the actual effect of using rim driven thruster on ships,this thesis selects an 8000 HP offshore platform support vessel with ducted propeller as the object for the ship model tests and numerical simulation calculation,which verifies the reliability of numerical simulation in the self-propelled state.Then the ducted propeller is replaced with rim driven thruster in numerical simulation for comparing propulsion performance in the ships.In this thesis,the method of predicting the hydrodynamic performance of rim driven thruster can be used for reference.The theoretical design method of rim driven thruster provides a way for the related research.The research on self-propelled can promote the application of rim driven thruster in ships. |
