碩士 / 國立海洋大學 / 系統工程暨造船學系 / 88 / In 1997, a three-bladed parent propeller with new section for high speed crafts with speed between 35 knots and 40 knots has been designed, and the performance of this propeller have been proven to be better than propellers with Newton-Rader section. In 1998, the research project for different number of blades and different pitch ratios has been continued. Four-bladed and five-bladed propellers with a pitch ratio 1.6 have been designed with a slight tip modification, and have been tested in the NTOU medium-sized cavitation tunnel. The performance at different cavitation numbers, different pitch ratios and different inclined shaft conditions has been determined. In this year, project will be continued. In addition to the redesign of a 3-bladed propeller with a pitch ratio 1.6, the tests for 3-bladed propellers with a pitch ratio 1.4, 1.6 and 1.8, and for 4-bladed propeller with a pitch ratio 1.8 are performed for propellers with expanded area ratio (EAR) 1.0. Finally 3-bladed propellers with EAR 0.75 and with a pitch ratio 1.4, 1.6 and 1.8 are also tested in order to establish a relatively complete series data.
From the test results, it is shown: At inclined shaft angle at any cavitation number, the efficiency of propeller with a pitch ratio 1.8 is higher than that of propeller with a pitch ratio 1.6. However, at , the efficiency of propeller with a pitch ratio 1.8 is almost the same as that of propeller with a pitch ratio 1.6, due to its higher vertical force.
Concerning the efficiency, it is obviously different between the propeller with EAR 0.75 and 1.0. The efficiency of pitch ratio 1.4 seems to be better than that of pitch ratio 1.6 and 1.8. Although the thrust and torque breakdown of the propellers with EAR 0.75 is serious compared with the propeller with EAR 1.0 at low cavitation number condition, its efficiency is still higher than that with EAR 1.0. However, the noise induced by propeller with EAR 0.75 is obviously higher than that of propeller with EAR 1.0.
| Identifer | oai:union.ndltd.org:TW/088NTOU0345006 |
| Date | January 2000 |
| Creators | Chin-Hong Liu, 劉錦鴻 |
| Contributors | Young-Zehr Kehr, 柯永澤 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 71 |
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