Numerical analysis of the impact of the bow thruster opening on a fast catamaran’s resistance

Steering a ship in confined waters is particularly important for the efficient operation of high-speed ferries. Bow thruster is the obvious solution. It may have however an adverse effect on the resistance of the vessel. The interference between demi hulls in the case of catamarans becomes an important and complex phenomenon as it affects many aspects of the hydrodynamic performance of the vessel. This study has focused on the analysis of the fluid flow around a fast catamaran with/without a bow thruster tunnel. A zero-carbon fast passenger ferry catamaran hull has been subjected to resistance simulations at two different speeds. Firstly, the catamaran hull without a bow opening has been simulated by commercial RANS solver software. After that, the simulations have been repeated for the catamaran hull with bow thruster opening. Finally, the bow opening has been filled with a gridded plane for garbage straining. The findings are very interesting for the fast catamaran ferry designers and operators. They are discussed for all three conditions in a comparative approach.