Abstract
By making use of the slender body theory, the author studies into the optimum configuration of the frame line form of ships.
Firstly, fixing his eyes upon the energy of the secondary flow around the frame line, he finds out that there are ship forms which have no secondary flow as like as rotational bodies, the stream lines on such body become approximately geodesic and, if so, there may be no cross flow in the boundary layer by Squire's theorem. He calls them Approximate Geodesic Stream Line Ship Forms and shows some examples represented by Lewis' conformal mapping function.
Secondly, he deduces some typical ship forms by setting simple characters upon the secondary flow and they contain the so-called U-frame, V-frame and bulbous bow form.
Lastly, he analyses three representative practical ship forms and finds out that the aft-bodies of three ship forms are all nearly the forms of which the secondary flow is the minimum.
Although the theory developed here does not foretell the resistance quantitatively, it seems very usefull to design the optimum frame line configuration of the ship.
