Open water performance of two different ducted propellers in oblique flow

Paper in proceeding, 2024

Ducted marine propellers provide increased efficiency, enhanced maneuverability, improved thrust, and reduced cavitation and noise in certain operating conditions. Ducted propellers may also offer advantages over propellers without a duct in waves. The duct surrounding the propeller can help minimize the effects of wave impact and reduce the blade loading variation as well as the risk of cavitation. This can result in improved propulsion efficiency and reduced vibration and noise levels. Additionally, the enhanced thrust generated by ducted propellers can provide better maneuverability and control in rough seas. However, there is limited documented evidence for the evaluation of the performance of ducted propellers in waves. To this end, this paper’s objective is to investigate the effect of ducts on the performance of marine propulsors in waves relative to calm water. Besides a conventional duct design, a special duct geometry that consists of a wavy leading edge is also studied. These investigations are carried out in open water through Computational Fluid Dynamics (CFD). A Kaplan series propeller, KA4–55, and the benchmark 19A-duct are used. The effect of waves on propeller performance is simplified by running the simulations in oblique flow conditions. It has been obtained that in oblique flow, with 19A duct, the propulsive performance increased with increasing angle of flow. Results have demonstrated that incorporating LET ducts can enhance duct thrust performance in straight flow conditions, even without any inclination.