Experimentally-based investigation of effects of wave interference on the wave resistance of asymmetric di-hulls

Significant reduction of steady-state resistance of a di-hull system with certain hull configurations (relative stagger and separation between the hulls) occurs because of interference effects between the two sets of ship-generated waves. The far-field wave interference and the resulting wave-resistance reduction of an asymmetric di-hull system, consisting of two distinct Series 60 hull models with various hull configurations are studied. The initial search for optimal configurations of the maximum prospective resistance reduction is conducted by an existing di-hull thin-ship computation. These theoretical results are then compared to the ones acquired by towing-tank measurements and those given by a semi-experimental approach. The latter approach obtains the wave resistance by combining experimental “wave-cut” data and analytical expressions developed for such a di-hull system. Experimental uncertainties are briefly discussed. Results of this study show that a considerable amount of wave-resistance reduction is indeed possible for the investigated hull configurations. However, beyond the far-field interference of the waves, near-field interactions of the two hulls are found to have non-negligible influence on the total resistance performance of the di-hull system.