Measurement and Discussion of Propeller Blade Tip Vortex Inception

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簡歷

基本資料

Project title

Code/計畫編號

MOST109-2221-E019-020

Translated Name/計畫中文名

螺槳葉尖渦空化起始量測與探討

Project Coordinator/計畫主持人

Yaw-Huei Lee

Funding Organization/主管機關

National Science and Technology Council

Co-Investigator(s)/共同執行人

周一志

Department/Unit

Department of Systems Engineering and Naval Architecture

Website

https://www.grb.gov.tw/search/planDetail?id=13542153

Year

2020

Start date/計畫起

01-08-2020

Expected Completion/計畫迄

31-07-2021

Co-Investigator(s)

Yi-Chih Chow

Bugetid/研究經費

886千元

ResearchField/研究領域

機械工程

空化(cavitation)一直是造船螺槳設計與研究之重點，目前空化起始試驗(inception)是採用人工觀察，依照ITTC規範，以觀察到葉尖渦空化(tip vortex cavitation，TVC)開始發生，而且持續固定間距秒數 1~10秒為基準做為空化起始，然而試驗跟據每人自身經驗決定，容易受主觀影響，致使無法準確量測，特別是對於將發生而又未發生之空化起始，造成相同的螺槳試驗結果無法一致。所以本研究採用光學式影像方法建立一套可以客觀而準確確認空化起始之方法。目前避免或延緩TVC發生，較佳方式為採用CLT (contracted and loaded tip)螺槳設計，然而CLT螺槳設計不易。因此本研究根據鯨鰭仿生研究，利用其導緣突節(leading edge protuberance)可以在較高攻角而不失速，應用於螺槳葉尖 0.9r/R以後，利用突節凹槽處會增加流速，進而達到避免或延緩TVC。因此本研究以單獨固定一片螺槳葉片建立螺槳空化起始量測方法，並且以此探討改變葉尖型狀為導緣突節，達到避免或延緩TVC之影響，研究並以立體式質點影像測速法(stereoscopic particle image velocimetry, SPIV)量測這兩種螺槳葉片流場特性，驗證TVC抑制之效果。 Cavitation has always been the focus of shipbuilding propeller design and research. At present, the inception of cavitation is based on manual observation and in accordance with ITTC norms, to observe the tip vortex cavitation (TVC). Occurred, and the cavitation was started with a constant interval of 1 to 10 seconds as the benchmark. However, the test is determined by each person's own experience and is easily affected by subjectivity, making it impossible to accurately measure it, especially for what will happen but not yet. It happened that the cavitation was about to start / end, causing the same propeller test results to be inconsistent. Therefore, this study intends to develop a method that can objectively and accurately confirm the onset of cavitation. At present, the occurrence of TVC is avoided or delayed. The preferred method is to adopt a CLT (contracted and loaded tip) propeller design. However, the CLT propeller design is not easy. Therefore, this study is based on whale fin bionics research. Using its leading edge protuberance, it is possible to use a leading edge protuberance at a high angle of attack without stalling. The cavitation initiation is used for the propeller blade tip after 0.9r / R. Efficacy is not significant, but TVC can be avoided or delayed by accelerating the tip velocity. Therefore, in this study, a propeller cavitation onset measurement method was established by separately fixing a propeller blade, and the change of the shape of the blade tip to the leading edge of the knuckle was discussed to cause the effect of avoiding or delaying TVC. The stereoscopic particle image velocimetry (SPIV) was used to measure the flow field characteristics of these two propeller blades to verify the effect of TVC suppression.

Keyword(s)

空化起始
葉尖渦空化
導緣突節
立體式質點影像測速法
inception
tip vortex cavitation
leading edge protuberance
stereoscopic particle image velocimetry

DSpace CRIS

Measurement and Discussion of Propeller Blade Tip Vortex Inception

基本資料

Description