An Application of Wave Pattern Analysis to Ship Form Improvement

Abstract

A method to apply wave pattern analysis to the ship form improvement is proposed. The principle of the method is to find a thin ship which is added to a given basic hull form so as to reduce wave-making resistance. The wave pattern of the thin ship is calculated theoretically and superposed linearly on the measured wave pattern of the basic hull form. To find the wave-making characteristics of the basic hull form, Hogner's idea of influence function is employed. The influence functions are calculated from measured wave data instead of theoretical calculation. Therefore they inform more realistic values of modifications than those by a pure theory only. Further, a method of empirical correction for the finite breadth effect of the given ship on the thin ship has been developed. Taking an example of ship form improvement, it is demonstrated how the present method works effectively in reducing wave-making resistance under appropriate design constraints such as constant beam and displacement.