Experimental and CFD Study of Wave Resistance of High-Speed Round Bilge Catamaran Hull Forms

Although catamaran configuration has been around for a longtime, it is only in the recent past that such hull forms have seen unprecedented growth in the high-speed ferry industry. One of the design challenges faced by naval architects is accurate prediction of the hydrodynamic characteristics of such vessels primarily in the areas of resistance, propulsion and seakeeping. Even though considerable amount of research has been carried out in this area, there remains a degree of uncertainty in the prediction of calm water resistance of catamaran hull forms. This research attempts to examine the calm water wave resistance characteristics of a series of round bilge transom stern, semi-displacement slender catamaran hull forms based on computational fluid dynamics (CFD) modeling. While maintaining the same center of buoyancy and displacement, the influence of hull shape has been examined, specifically the effects of demi-hull spacing in the speed range corresponding to Froude numbers of 0.2 to 1.0. The results of CFD analysis have been compared with experimental towing tank results of NPL series, which closely resemble the systematic series developed here. The results obtained show considerable promise and development of an industry standard regression equation based on the data obtained from CFD analysis, model experiments and full-scale ship trials, can be seen as achievable.