Powering and Motion Analysis of Twin-Strut Swath Vessels

The hydrodynamic characteristics of three different underwater hull forms of the SWATH type are studied based on their powering and motion performance. A SWATH is a twin-hull ship design that holds various advantages over the conventional mono-hulls. The shape of the underwater hull and the struts determine the resistance and motion characteristics of the SWATH. It is important to arrive at an optimum hull shape for maximum performance. SHIPFLOW, a CFD tool developed especially for the marine industry, is used to estimate and compare the resistance and powering characteristics of the three designs. SEDOS, a motion analysis package based on strip theory, is used to estimate the seakeeping characteristics of the hulls. Comment is made on the actual performance on trials when compared against the tank test results, together with the results from various numerical prediction methods. Based on the results for the three hulls, the most optimum design is found out. Keywords: Resistance, Seakeeping, SEDOS, SHIPFLOW, SWATH