MULTI-SHAPE PROPELLER CAP WITH GUIDE FINS FOR MINIMIZING ROTATIONAL FLOW AND HUB VORTEX AND IMPROVING PROPULSION EFFICIENCY

摘要

The present invention relates to a composite propeller cap with guide fins for reducing a rotational flow and a hub vortex and improving propulsion efficiency. 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 plate shape is attached between a contraction portion and a diffusion portion of the propeller cap to untangle a flow tangled before a rotational flow induced from propeller rotation reaches the diffusion portion of the propeller cap to a certain degree to change the rotational flow by the propeller rotation into a linear flow in a direction of a rotary shaft to additionally reduce generation of hub vortex cavitation to reduce the rotational flow and 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.