| With the implementation of the Ship Energy Efficiency Design Index EEDI by International Maritime Organization(IMO),the ship industry has entered a new stage in which energy conservation and emission reduction are regarded as the new goal.Green ship technology is becoming more and more important in the field of ship hull form design.Ship manufacturing technology has been very mature after many years development.As the main ship type,low-speed fertilizer large ships generally have quite limited improvement on performance.Low speed fertilizer large ships generally have a long parallel medium body.The only spaces that can be optimized are generally the bow and stern.And the displacement and floating center position of the ship are usually limited during the hull form optimization,so the wet surface area of the hull will not change much.Therefore,the friction resistance of the main components of the ship’s total resistance will not change much.The wave resistance of low speed ship is generally small,so viscous resistance is the only component of the total resistance that can be changed during the change of the ship hull form.The viscous pressure resistance is obtained by the integral of the pressure distribution of the whole hull surface,and the complex surface change of the hull leads to the complex distribution of the viscous pressure resistance,which makes the calculation method of the viscous pressure resistance also very complicated.Therefore,the optimization of resistance performance of low speed fertilizer large ships is a difficult problem in the research of ship optimization and there are limited research.In this paper,the approximate model method is applied to ship type optimization,and an approximate model is established by using a limited number of high-precision CFD calculation results instead of complex and time-consuming CFD numerical calculations during the optimization in order to save time.The main work of this thesis is as follows: 1)The background and connotation of ship type optimization problem are introduced.This paper analyzes the connotation of ship type optimization problem,summarizes the frame of concrete work of ship type optimization,and summarizes and summarizes the composition and principle of each module.This paper introduces the optimization platform of ship type design independently developed by this team,and introduces the function of the platform.This brief explanation of how to use the platform,including the specific functions and working principle of each module.2)The surface deformation work of 46000 DWT oil tanker is introduced.The interpolation technology of radial basis function is briefly introduced,and the method and principle of modifying hull surface based on radial basis function interpolation technique are described.The hull surface of 46000 DWT oil tanker was modified by using the interpolation technique of radial base function.3)A CFD software FINE/Marine is used to calculate the resistance performance of 46000 DWT oil tanker,and the ship model test is verified,which shows the validity of the calculation results of CFD software.The approximate model of resistance performance of 46000 DWT oil tanker is established,the hull line of 46000 DWT oil tanker is optimized,and the ship type of the optimized ship model is tested,and the results of the optimized vessel resistance test are compared with the results of the resistance test of the mother-type ship.Based on the above research,this paper presents a total resistance optimization method for low speed mast ship,and optimizes the 46000 DWT tanker type line,and the ship model test verifies the effectiveness of the method. |
