Research On Parametric Optimization Design Method Of Small Waterplane Area Twin Hull Forms

With the rapid growth of the marine economy,people’s requirements for ship performance continue to increase,and various new ship types are constantly being developed and researched.The Small Waterplane Area Twins Hull(SWATH)has attracted more and more attention from the shipbuilding industry due to their excellent seakeeping performance and large deck area.The speedability and seakeeping of the SWATH ships have been one of the research focuses in the field of ships in recent years.Compared with a monohull with the same displacement,the SWATH has a larger wet surface area,which reduces its speedability.In addition,due to the needs of marine economy and scientific research,the tasks performed by the SWATH ships at sea are more arduous,and its seakeeping during sailing time is also worthy of attention.Therefore,in this paper,for the resistance and seakeeping of the SWATH ships,the relevant research on the parametric optimization design method of the SWATH is carried out,and the major contents are as follows:First,construct a parametric model of SWATH,and analyze the sensitivity of SWATH design parametric to SWATH resistance at different speeds.Integrate the SWATH parametric model,numerical simulation,and SOBOL algorithm to build a set of parametric SWATH automatic calculation framework based on numerical simulation,and automatically predict SWATH resistance at different speeds.Based on the sample calculation results,analyze and discuss the influence of design parameters on resistance at different speeds.Secondly,the SWATH resistance optimization is carried out based on sensitivity analysis.Based on the results of the sensitivity analysis,the design parameters that are more sensitive to resistance are selected as optimized design variables and a multi-objective optimization model of SWATH resistance at different speeds.The SWATH numerical simulation automatic calculation framework and the optimization algorithm are combined to construct an automatic optimization design system,and the optimization design system is used to complete SWATH resistance optimization at different speeds.Thirdly,based on the AQWA software,the seakeeping prediction of the optimal and original SWATH is performed.The motion response of each SWATH ship in regular waves at different speeds is calculated,including heave and pitch motions,and the heave and pitch RAO curves are plotted.In addition,the heave and pitch characteristics of the original and optimal SWATH are analyzed.Finally,a comprehensive evaluation model of SWATH performance based on synthesized weight and TOPSIS is established to evaluate the resistance and seakeeping of SWATH ships.The original and optimal SWATH ships are selected as the evaluated objects,and the resistance and seakeeping indexes are extracted from the results of SWATH resistance and seakeeping calculation,and the composite weights of the indexes is construted based on the analytic hierarchy process and the entropy weight method.The performance of each SWATH ship is comprehensively evaluated and ranked based on the TOPSIS principle by calculating the relative proximity of all evaluated objects.To sum up,this paper mainly studies the parametric optimization design method of SWATH forms,gives the fully parametric modeling and sensitivity analysis method of SWATH,carries out the automatic optimization design of SWATH minimum resistance hull form,calculates the seakeeping of SWATH ships,and carries out the comprehensive evaluation of SWATH performance based on synthesized weight and TOPSIS.It provides reference and guidance for the optimization design method of SWATH.