Research On Optimization Of Hydrodynamic And Low-drag Configuration Of Pod Thrusters

With the characteristics of space saving,easy installation,high propulsion efficiency and strong maneuverability,pod thrusters have been widely used in the ship industry and have gradually become a research hotspot in academia.At present,the research is mainly aimed at the hydrodynamic performance of the pod thruster under direct flight conditions,but the pod thruster can rotate 360°,and the thrust and torque of the pod thruster in the swing state will increase rapidly with the increase of the swing angle,resulting in the pod thruster bearing great load and even damaging the structure.Therefore,it is of great significance to analyze the hydrodynamic characteristics of the pod thruster during the rotation.At the same time,with the enhancement of people’s awareness of environmental protection,people have carried out in-depth research on the low-resistance optimization of the hull,such as the optimization of the bulbous bow and the optimization of the propeller line,but the low-resistance linear optimization of the pod thruster has not been deepened.Therefore,it is very meaningful to study the hydrodynamic performance prediction and the optimization of the low resistance line shape of the pod thruster during the full rotary operation,especially for the development of the ship propulsion system.system.In this thesis,FINE/Marine software is used as a tool to study the open water performance of pod thrusters by using slip grid technology.The hydrodynamic characteristics of the pod thruster during rotation were calculated and analyzed by using the double slip grid technology by using the double slip grid technology.Using the CAESES optimization platform,the line type of the pod body was optimized with the minimum resistance of the pod thruster as the optimization goal.The basin of the pod propeller was analyzed,and the deformation and hydraulic characteristics of the pod propeller model before and after optimization were compared and analyzed.(1)This thesis summarizes and analyzes the calculation of hydrodynamic performance under open water condition and full rotation condition of pod thruster and the development status of hydrodynamic shape optimization design at home and abroad.The methods and steps for optimizing the hydrodynamic and low-drag configuration of pod thrusters are proposed.(2)When using FINE/Marine software to analyze the open water characteristics of pod thrusters.Firstly,the hydrodynamic performance under different working conditions is calculated.Draw the open water curve of the pod propeller;According to CFview,the corresponding pressure field,velocity field and vortex cloud map are drawn,and the flow field information of the pod thruster is analyzed.(3)Using FINE/Marine to calculate and analyze the hydrodynamic load during the rotation process of the pod propeller,complete the numerical simulation of the rotation process of the pod propeller under three working conditions,and analyze the pod during the full rotation process of the pod propeller The variation of the propeller hydrodynamic loads and the flow field during a full revolution are analyzed in detail.(4)Based on CAESES optimization software and hydrodynamic shape optimization theory,complete the parametric modeling and shape optimization design of the pod propeller.Firstly,the parametric model of the pod propeller is constructed;secondly,the line shape of the pod body is optimized by using the SOBLO optimization algorithm with the lowest resistance as the optimization goal;Set the variation range of the characteristic parameters.The structure and hydrodynamic performance of the model before and after optimization were compared and analyzed.