Numerical Simulation Of Resistance And Ship Form Optimization Of Semi Planing Craft Based On CFD Method

Marine patrol boat is the daily patrol and law enforcement vehicle of maritime department.Its specific tasks mainly include water patrol supervision,vigilance and supervision,maintenance of water order,traffic guidance,on-site rescue and response to water emergencies,which are arduous and urgent.In view of this characteristic,researchers pay more and more attention to the research on the rapidity of sea patrol boats.At present,for the design of maritime patrol boat in Heilongjiang area,researchers mainly use empirical formula to estimate the ship resistance and modify the parent ship to get a new ship.This method has strong subjectivity and randomness,and can not guarantee the ship resistance and other performance.In order to improve the design efficiency of the inland patrol boat,this paper takes the inland maritime patrol boat with a total length of 13.5m as the research object,and studies the full parametric modeling and resistance numerical simulation of the semi planing boat,as well as the method of line optimization based on the parametric model.Firstly,this paper studies the parametric modeling method of inland maritime patrol boat.According to the analysis of the relevant characteristic parameters of the whole ship,the decision parameters are selected,the relevant influence parameters are classified,and the characteristic curve is established according to the classification parameters;According to the selected characteristic parameters and the established characteristic curve,the full parametric modeling of the inland maritime patrol boat is carried out,and the trust degree of the parametric modeling is verified by comparing with the real ship data.Then,based on the CFD method,the resistance numerical simulation of patrol boat in still water at different speeds is carried out,and the results are compared with the modified sit calculation results to verify the accuracy of the numerical simulation method.The trust degree of resistance numerical simulation lays a solid foundation for the subsequent implementation of ship type optimization combined with mathematical optimization method.Finally,the ship shape optimization with ship resistance as the optimization objective is completed.Under the control range of the error variation of the first level related initial design parameters,the DOE method is used to analyze the influence of the second level parameters,and then the Sobol algorithm is used to analyze the sensitivity of the related parameters,and then the non genetic dominated algorithm NSGA-Ⅱ based on Pareto elitist strategy is applied to establish the mathematical model with the determined influence parameters as variables,The initial design parameters of the first layer are taken as the constraints of the objective function,the corresponding variation margin is controlled,and the navigation resistance is taken as the optimization objective to optimize the ship form,and finally a better optimized ship form is obtained.In this paper,based on the CFD method of resistance numerical simulation and ship form optimization as the main research content,completed the full parametric modeling scheme for the inland patrol boat,then carried out the resistance numerical simulation calculation of the parametric model,and then optimized the parametric ship form,The research results of this paper have a certain contribution and corresponding application prospect for the numerical simulation of resistance and ship type optimization of inland river sea patrol boat,and have corresponding engineering practicability and reference value for the current research and design improvement of patrol boat rapidity.