CAVITATION STUDY OF DUCTED PROPELLERS ON LARGE SHIPS
The increase in ship size in recent years has brought about an increase in propeller load and thus an inevitable decrease in propeller efficiency. Adoption of the ducted propeller is one of the ameliorating measures, and not a few large ships--sixteen mammoth tankers, two ore carriers, and one liquefied petroleum gas carrier--built by the authors' company were fitted with ducted propellers. Cavitation erosion, however, occurring atop the duct on the inside, has proved to be an unfavorable factor of the design. This paper reports on full-scale ship observations of the cavitation conducted on seven ships by means of TV cameras coordinated with stroboscopes, as well as the results of erosion model tests. Air injection into the incoming flow to the propeller--a technique tried recently on three new ships--seems to be a partially effective countermeasure.
- Presented at the Annual Meeting of the Society of Naval Architects and Marine Engineers, New York, New York, November 13-15, 1975.
Society of Naval Architects and Marine Engineers601 Pavonia Avenue
Jersey City, NJ United States 07306-2907
- OKAMOTO, H
- Okada, K
- SAITO, Y
- Takahei, T
- Publication Date: 1975-11
- Features: References;
- Pagination: 16 p.
- TRT Terms: Cavitation (Mechanics); Cavitation erosion; Ducted propellers; Propellers
- Subject Areas: Marine Transportation; Vehicles and Equipment;
- Accession Number: 00127556
- Record Type: Publication
- Source Agency: Society of Naval Architects and Marine Engineers
- Report/Paper Numbers: No. 7
- Files: TRIS
- Created Date: Nov 18 1975 12:00AM