Concepedia

Publication | Open Access

A Research and Development of PBCF (Propeller Boss Cap Fins)

DOIFull Paper Access

25

Citations

0

References

1988

Year

Kazuyuki Ouchi, Michihito Ogura, Yoshio Kono, Hironobu Orito, Takashi Shiotsu, Masahiro Tamashima, Hajime Koizuka
Journal of the Society of Naval Architects of Japan

Abstract

It is well known that a screw propeller generates free vortexes called tip vortexes and a hub vortex in its slipstream. In this paper, PBCF (Propeller Boss Cap Fins) which diffuses and weakens a hub vortex by changing the flow near by propeller boss cap is proposed in order to enhance the efficiency of ship's screw propeller.The research and development of PBCF was carried out through Flow Visualization, Propeller Open Test, Self Propulsion Test and On Ship Test to make the PBCF practical.As the result of various experiments, gains of 3 to 7% in propeller efficiency, gains of approx. 2% in self-propulsion efficiency of 7 m Model ship and gains of approx. 4% in terms of power output on 44, 979 Gross Tonnage PCC “Mercury Ace” were obtained. These data lead us to believe that PBCF can be excellent energy-saving device with its simple structure.