A Method for Optimization of Ship Hull Forms based on Wave-pattern Analysis Data

Abstract

This paper presents a method for optimization of ship hull forms on the basis of wave pattern analysis.The method is primarily based on the assumption that a linear relation exists between the small difference of prismatic curves and the difference of the amplitude functions of the generated waves.Firstly wave analysis data are collected of several ship models with variant prismatic curves including the specified ship model. If the difference of prismatic curve, ΔCpj (ξ), and the difference of amplitude functions, ΔPj, ΔQj, between the specified ship model and the other ship models are known, the modification to be made for a designed ship, ΔCp (ξ), ΔP, ΔQ, can be expressed by the following linear equations : ΔCp (ξ) =∑ajΔCpj (ξ) (i) ΔP+iΔQ=∑aj (ΔPj+iΔQj) (ii) As for the coefficients, ajs, as the wave-making resistance coefficient, Cw, of designed ship model is to be derived by making use of ΔP and ΔQ in the equation (ii), the ajs are determined so as to minimize Cw.The author's method was verified to be successful in the case of being applied to the prismatic-curve series of the ship models with the same hull-form factors. Further study is under way towards extending this method to the case of ship models having different hull-form factors.