A power prediction method and its application to small ships

A mathematical model is derived by which it is possible to describe the resistance and propulsion properties of ships as a function of the Froude number, the Reynolds number and the general form and propeller parameters. The coefficients of the mathematical model have been calculated for small ships such as trawlers and tugs from random tank data, obtained from the N.S.M.B.-statistics. With the present method it is possible to make an approximation of the resistance and required power which is accurate enough for design purposes. The method is suitable for programming.