A method for rapid hull form development and resistance estimation of catamarans

Catamarans are being built with higher speed capability for transportation of passengers and for other applications. The wide deck area and large transverse stability are attractive features that account for the high demand for this class of vessels. A rapid hull form development, combined with assessment of resistance is presented here. The hull form development is based on simple inputs for the polygon net, and using the bi-parametric bi-quintic surface in a computer-aided development scheme, a faired 3-D surface is developed. The hull volume is computed and iteratively matched to the targeted volume. Using the developed form, a formulation based on Mitchell's theory for slender vessels, combining wave interference factor and viscous interference factor, is used to arrive at the total resistance of the combined hulls. The method is demonstrated for a series of 9 catamaran forms. The forms have varied geometric ratios, but a common displacement of 180t. The method is presented as a rapid development and resistance assessment tool.