Research On Optimization Design Of Hull Lines And Minimum Resistance Hull Form

Under specified requirements of deadweight as well as design condition,the procedure of determining the optimal hull from which involves some important properties such as rapidity,maneuverability and seakeeping is very important but also complicated.The designer's first priority is to determining the hull form with the least resistance.The methods used currently which involve the reference of the basic ship,the experience of designer and ship model trial not only take much time and cost but also are restricted.As the development of hydromechanics and the computer science,the optimized design method of ship lines based on the theory of hydromechanics has gradually become practical.The new technology has been used in production by Korea,Japan and other European countries while the traditional method based on the designer's experience is mainly used in China.Nowadays, though China's production capacity is in the front ranks of the world,the technology we used lags behind.It is urgent to research the optimal method which could rapidly produce ship lines with the least resistance and develop our own software of ship lines optimal design to improve our competitiveness in world market and the research productivity in our shipbuilding enterprises.Due to the urgent requirement stated above,The article is dedicated to investigate the method which could rapidly produce ship lines with the least resistance and to develop our own software of ship lines optimal design.The objects optimized include stem,forward bow and the hull form under the waterline at aft stem The article chooses Fortran as programming language,Tecplot as the software of post processing,AutoCad as the display tool,using the combination of potential flow,viscosity theory and optimization techniques as well as CAD, to develop the software of ship lines optimal design.The reduction of the wave-making resistance is the main purpose in procedure of optimal calculation.Considering the effect of viscosity separation at stem,the wave-making resistance is calculated using Michell integral method and Rankine method and combined viscosity separation to evaluate the increase of viscosity resistance.The offsets are expressed by the offsets of basic ship and hull form modification function.The article chooses the traditional optimal method-nonlinear programming method and intelligent optimal method-genetic algorithm(including simple genetic algorithm and niche genetic algorithm) as the major optimal methods.The article is new development of ship lines optimal method,providing the theory foundation and technical support of hull form optimization for ship design and shipping sector to achieve economic benefit and improve the competitiveness our shipbuilding enterprises in world market.