PROPELLER CAP WITH GUIDE FIN FOR MINIMIZING HUB VORTEX AND MULTI-SHAPE FOR IMPROVING PROPULSION EFFICIENCY

摘要

The present invention relates to a composite propeller cap with a circular guide fin for reducing hub vortex cavitation. According to the present invention, a diffusion-type propeller cap is mounted on an end of a conventional contraction-type propeller cap to form a propeller cap of a composite form. A guide fin of a circular ring shape is attached to an end of the propeller cap to weaken strength of a vortex while a rotational flow induced from propeller rotation passes a diffusion portion of the propeller cap. A vortex created by gathering flows while the rotational flow moves along the guide fin near the end of the propeller cap is prevented to additionally reduce generation of hub vortex cavitation to reduce the hub vortex cavitation generated behind a propeller. The composite propeller cap has a very simple structure and can be easily manufactured at lower costs in comparison to a conventional PBCF.