CFD Simulations of Basic Stepped-Hull Configurations in Planing Regime Using Star-CCM+ Software

High-speed marine vehicles often employ stepped hulls with the purpose of ventilating bottom surfaces with air, thus reducing the hull’s water resistance. Due to the large number of possible geometrical variations for stepped hulls, numerical simulations can potentially make the process of designing such hulls more effective. In this study, the computational fluid dynamics software Star-CCM+ (version 15.04.008) is applied to comparing the numerical results with the experimental hydrodynamic data available for prismatic hulls with one and two steps. Additionally, simulations are carried out for steps with different sweep angles, for three- and four-step hulls, and for a stepped hull in shallow water. Reasonable agreement with the test data was obtained, although some underestimation of drag and overprediction of air-ventilated zones were noted. In the studied conditions, increasing the forward sweep angle of a step, employing multi-step configurations, and operating in shallow water demonstrated further reductions in the wetted areas and the attainment of higher lift–drag ratios.