Pages 29-34
This paper describes an attempt of improving ship prismatic form. i.e., longitudinal displacement distribution, for minimizing ship wave resistance. The method adopted here represents the prismatic curve by use of B-spline function, takes the coefficients of the B-spline as the design variables, and evaluates the wave resistance value by Michell approximation which assumes an infinite-draft ship form with the beam profile same to the prismatic curve of the ship form considered. Then a feasible direction method is applied to the optimizing process including the above procedure of wave resistance computation. It is found that the convergence of the iterative optimizing process is quite rapid and steady, and that the method is useful for practical initial design of ship forms, although it also leaves some aspects of improvement such as wave resistance calculation method and extention to 3-dimensional case.
