Lightweight hull surface self-design vertical parameterization method based on NURBS

ZHANG Yanru1，LIN Yan 1，2，LU Conghong1，JI Zhuoshang1 1 School of Naval Architecture Engineering，Dalian University of Technology，Dalian 116085，China 2 State Key Laboratory of Structural Analysis for Industrial Equipment，Dalian University of Technology， Dalian 116085，China

Abstract：［Objectives］At present, conventional design is limited to parent ship design space, and cannot drive ship hull design using as few parameters as possible. In order to solve the above problems, ［Methods］by combining the draught function with NURBS, a ship hull surface self-design method based on vertical parameterization is proposed. In this method, the waterline is designated as the basic design unit; the bottom flat end line, designed waterline, stem and stern contours, side flat end line and maximum section line are designated as the characteristic constraints of the ship hull; and the draught function values corresponding to the characteristic parameters are designated as the design objectives. In this way, a waterline approximation model is built, and an evolutionary algorithm can be used to solve the approximation model. Finally, the ship hull surface is generated on the basis of the waterline using the NURBS skinning technique.［Results］The design examples of the characteristic curves of the full-scale ship hull surface indicate the practicable and advanced nature of this method.［Conclusions］ The hull surface can be designed with as little data as possible using this method, making it much more suitable for the self-design of new ship forms. Key words：NURBS；hull surface；self-design；vertical parameterization；characteristic curves