A Study on The Performance Improvement of Hi-Fin

Abstract

Efforts to improve propulsion efficiency of a ship in maritime industry are ongoing, researchers are trying to develop a new type of Energy-Saving Devices for better performance. This study deals with fuel saving device called Hyundai Propeller Boss Cap Fin (Hi-Fin®) attached at the hub of the propeller and aimed to investigate the new type of Hi-Fin® to improve propulsion efficiency. Moreover, in order to evaluate the performance of Hi-Fin® more accurately, model tests were conducted at the large cavitation tunnel as well as the towing tank. For this purpose, two kinds of Hi-Fin® with different geometry were designed using self-propulsion CFD analysis considering hull-propeller-rudder interaction. The first was conventional type of Hi-Fin® which has flat plate fin. The other was designed with NACA66 hydrofoil section. Propulsion tests were conducted at the towing tank in HMRI with two designed cases and power savings of Hi-Fin® were also measured at the large cavitation tunnel in KRISO. In the large cavitation tunnel tests, tunnel flow speed and rotational speed of propeller were adjusted in order to investigate the Reynolds number effect on the propulsion performance. The results showed that the Hi-Fin® designed with NACA66 hydrofoil section had better propulsion performance than the flat plate design. And power saving effect of Hi-Fin® is increased at a high Reynolds number in the large cavitation tunnel when compared with the results at relatively low Reynolds number form the towing tank.