The influence of propeller root geometries on cavitation pattern at inclined shaft condition

• Main Authors: Shin-Zhou Chen, 陳信州
• Other Authors: Young-Zehr Kehr
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/96301275270273425495

碩士 === 國立臺灣海洋大學 === 系統工程暨造船學系 === 96 === Due to the inclined shaft condition, the angle of attack of high-speed propeller will be increased significantly, especially at the root of the propeller, when its blade rotate to 90 degrees circumferentially. It will make root erosion easily. Countermeasures such as increasing and reducing the chordlength, adopting trailing edge truncation and cupping at propeller root, are investigated. The test condition is at inclined shaft 10°,cavitation numbers are 0.75 & 0.6 . The K-J chart will be measured and the cavitation pattern at propeller root will be photographed. From the results of the experiment, it is shown that chordlength reducing at propeller root make the cavitation easily to happen. At low cavitation number, the efficiency will be reduced remarkably. Cordlength increasing at propeller root, the cavitation would be improved at low cavitation number. Trailing edge truncation can control cavitation at propeller root efficiently. Cupping makes the cavitation stable from leading edge to trailing edge at root when the blade rotates to 90 degrees, and makes face cavitation when blade rotates to 270 degrees.