A LONGITUDINAL-CUT METHOD FOR DETERMINING WAVEMAKING RESISTANCE

A longitudinal-cut technique for computing the wave resistance of ship models moving in a towing tank is developed. The method uses finite-limit integrals of the wave profile along a line parallel to the ship motion. Solution of a set of simultaneous equations yields a set of coefficients which are in turn used in a series expression for wave resistance. This technique allows the wave resistance to be calculated from longitudinal-cut records of finite length, including multiple wave reflections from the walls of the channel. The accuracy of the method is verified by applying it to the wave system produced by a moving source distribution. A linear source distribution on the vertical plane of the ship midsection, and extending from the water surface downward, is used in this study. The computed wave resistance is compared with the known exact value for the source distribution. The numerical study indicated that the method predicted the wave resistance to within one percent of the exact value for almost all choices of Froude number, model length, and tank width. The applicability of the method was also verified for a Series 60, 0.60 block-coefficient model, 10 feet long.