臺灣博碩士論文加值系統

由於高速螺槳運轉於斜軸狀況之下，葉片轉至90度位置攻角大幅上升，尤其是根部位置，於根部很容易造成空蝕現象，本文將採用根部弦長縮短、根部弦長加長、根部作尾緣切斷(trailing edge truncation) 與根部作彎殿緣(Cupping) 等方式，來探討是否可以減輕根部空化現象，或空泡是否會僅發生於艉緣，而破裂於根部後方，以避免葉片表面侵蝕之發生。本文將測試斜軸10度之狀況，空化係數為0.75與0.6，並量測其K-J圖，重要之現象將拍照紀錄。
由實驗結果顯示：根部弦長縮短的螺槳於低空化係數時，其空化狀態都很明顯，導致效率降低，且由於氣泡涵蓋過大，無法由照片判定氣泡是否僅破裂於葉片後方。而根部弦長加長的螺槳於低空化係數時空化現象有明顯之改善，但螺槳葉片不論轉至90度或是270度仍難避免空化現象的發生。作艉?切斷的螺槳能有效降低氣泡發生，於低空化係數時僅剩少量氣泡，可能使其不發生葉片侵蝕現象。根部作彎殿緣的螺槳雖然能使空化現象由導?以穩定形態延伸至艉?，當螺槳葉片轉至270度時卻有正面空化產生。

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.

中文摘要……………………………………………………………………i
英文摘要……………………………………………………….….……….ii
圖目錄 iv
表目錄 ix
符號說明 x
第一章 研究背景與前言 1
第二章 測試螺槳與其參數變化範圍 4
第三章 實驗結果與討論 23
3.1 螺槳P4012、P4019、P4020、P4021與P4022之實驗結果比較 23
第四章 結論與建議 52
參考文獻 54
附錄一 實驗系統簡介 55
附錄二 螺槳根部幾何示意圖 58
附錄三 彎殿緣定義 63

1. Rader, H. P. , “Propeller bei Schraeganstroemung,” Jahrb. Schiffbautechnischen Gesellschaft , Band 68 , pp. 261-290 (1974)
2. Kehr Y.Z. , W.C. Lee , C.Y. Hsin , 2005, “Performance Improvement of High-Speed Propellers At Inclined Shaft Conditions By Root Unloading” 8th International conference on Fast Sea. Transportation, St-Petersburg, Russia
3. 柯永澤、李文琪、莊育霖、陳正泰，2003，高速艇螺槳效率與性能探討及試驗，經濟部九十二年度科技專案研發成果，船舶技術發展第二期四年計畫。