Hull Form Design Optimization Of Ocean Fishing Vessel Based On SBD Technique

As the international maritime organization responds to the development trend and requirements of the future green economy,the energy saving and consumption reduction of green ships has become the general trend.As a core link in the overall design of a ship,ship form design is a basic technology with the deepest impact and the longest effect for energy saving.The mainstream of traditional hull shape optimization is the selection / optimization of multiple schemes.It will be difficult to make breakthrough progress and seriously restrict the improvement of the innovative design ability of the hull configuration.With the progress of the times and technological innovation,the optimization technology is introduced into the field of ship design and successfully combined with advanced CFD technology.The developed SBD technology has opened up a new situation for ship hull form optimization design and configuration innovation.Ship hull form design based on SBD technical thoughts has broken through the limitations of traditional ship hull form optimization technology,realized the direct optimization of the objective function,and promoted the transformation of engineering design from the traditional empirical design mode to the knowledge-based design mode,which has become a research hotspot at home and abroad.Therefore,the research in this paper mainly focuses on the new ship hull form optimization design concept based on SBD technology.Taking an ocean-going fishing boat as the research object,the research is carried out around full parametric modeling,focusing on breaking through the hull geometric reconstruction technology,while relying on advanced and reliable CFD technology and using optimization technology,comprehensive integration technology to establish a ship hull form optimization design framework,and finally completed the optimized design of the ship type with the best total drag performance.Based on this,the research content of this article mainly involves the following aspects.First of all,research is carried out on the full parametric modeling of ocean-going fishing vessels.This part is mainly carried out in two steps.The first is the analysis and selection of ship-type characteristic parameters.By analyzing the geometric characteristics of the ship type,the main parameters and characteristic curves for expressing the ship type are determined,which is an important premise and basis for full-parameter modeling;The second is to complete the full parametric modeling of the hull surface according to the characteristic parameters and curves of the ship shape.Full-parameter modeling establishes the mapping relationship between the ship type and the main characteristic parameters and curves,and realizes the transformation of the optimized design of the ship type into the characteristic parameters and curves that are more in line with the target,thus laying the foundation for the rapid design of the target ship type.Secondly,on the basis of elaborating the numerical calculation method of ship resistance based on CFD,this paper aims at optimizing the total resistance performance,and uses the potential flow surface element method based on Rankine source and RANS method to solve the wave-making resistance and viscous flow of the ship form resistance,thus completing the preliminary calculation of the ship's total resistance performance.The numerical calculation of ship resistance based on CFD is an important prerequisite for the subsequent automatic optimization combined with optimization technology.Finally,the ship type optimization with the best total resistance of the ocean-going fishing vessel is completed.Firstly,based on the researched ship type optimization problem,a complete optimization mathematical model is established,then based on the established full-parameter model of ocean-going fishing vessels,reasonable design variables and constraints are determined,and finally combined with CFD numerical calculation and selected optimization algorithm to complete the optimized design of the ship type with the best total drag performance.The optimized drag results of this paper decreased by 12.2%,indicating that the ship-type optimization design method based on full parametric modeling proposed by this paper under the guidance of SBD technical thought has strong engineering practicality and broad application prospects.