Catamaran-stern Hull's Lines Character And Local Transformation Method Research

Catamaran-stern hull developed quickly in world since it's invented, it's character has made it a widely ship hull form in ship design in world, especially in the our country's ship design, As an excellent hull form, it gain more and more attention since its come out and has been extended in the world's ship design. Catamaran-stern hull, as an outstanding hull lines in ship evolution history, have achieved great economic benefits, worthing of Research and development.the main task in ship design is working out ship hull lines with good performance and that can save resource still, and Catamaran-stern hull form is a excellent hull form that has been proven; in order to do further research on this hull form, this article analyse Catamaran-stern hull ship in detail, set forth Catamaran-stern hull's evolution history and current development. It's also prove Catamaran-stern hull is an excellent hull form compared with other hull types in the base of large research data of ship performance, identifying the parameters that impact Catamaran-stern hull lines, pointing out how different parameters that can effect Catamaran-stern hull lines and their respective advantages and disadvantages.Now we have some methods to design this complicated hull lines, and in this article I employ parent hull change method to design ship lines. This method can design hull lines easily, reducing the work time and understanding some lines characters in design. The main hull transformation this article is parent hull transformation, which can be divided into three methods: Laikenbei transformation, subsection linear transformation and angel change.Laikenbei transformation method was introduced in 1950, it can also satisfy the prismatic coefficient of design ship, longitude position of floatation, the changes of parallel body. Laikenbei can change the characteristics of the area curve flexibly according to need and meet the accuracy requirements.Local transformation have two types. One is consulting napa software's disposal to the hull lines, the first step is the subsection linear change, and then through the interpolation to get the standard stations values, The other is change the angle of Catamaran-stern hull lines, through which you can get a smooth ship lines with a different angle of Catamaran-stern lines.The last is to sum up the final conclusions and made the conclusions of this design.