Ride-Control Systems Geometries on a High-Speed Catamaran Using a CFD Forcing Function Method

Controlling vessel motion using hydrofoils to ensure smoother journeys is a widely adopted practice. Incat Tasmania has implemented the Ride-Control System (RCS) on their Wave-Piercing Catamaran (WPC) fleets, consisting of a T-foil and two stern tabs. To efficiently evaluate the effectiveness of different RCS geometries, a novel Computational Fluid Dynamics (CFD) approach, the Forcing Function Method (FFM) was developed and validated. The present paper encompasses two main components: a standalone T-foil analysis and an assessment of the influence of various RCS geometries on a WPC by FFM. In the standalone T-foil study, the lift and drag forces were investigated with respect to the angle of attack and immersed depth. The results indicated that the T-foil lift coefficient diminished logarithmically by decreasing the immersed depth smaller than 1 chord length. The present paper utilises the FFM to examine different RCS geometries on a 2.5 m WPC operating at a speed of 2.89 m/s (Fr∼0.6). The effectiveness of motion control is evaluated by measuring the changes in sinkage and trim over time after deflecting the FFM T-foil by ±15° in calm water. Through these CFD simulations, the impact of total planform area, number of T-foils, and longitudinal location of the T-foil were analysed. It was found that controllability of motion was a function of total planform area, regardless of the number of foils, and although moving the T-foil away from the bow reduces motion control in trim, it does not affect sinkage significantly. The study also highlights the efficiency and accuracy of the FFM method for integrating hydrofoils into marine vehicle simulations. These insights contribute to the advancement of RCS development and offer valuable guidance for future research and design of hydrofoil systems. The proposed FFM approach has the potential to expedite the development process and enhance the performance of hydrofoil-equipped vessels in diverse operating conditions.