丁肇隆林銘崇臺灣大學：郭庭瑋Kuo, Ting-WeiTing-WeiKuo2007-11-262018-06-282007-11-262018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/51103摘 要 本文應用已建立之粒子影像速度儀（Particle Image Velocimetry）在循環水槽中分別量測兩種不同幾何形狀之物體（圓柱體及NACA0018翼形體）與平板交接處之接面渦漩（juncture vortex）流場。於四種不同雷諾數之紊流流場中，主要的流場特性為物體上游對稱面處存在一渦流系統，此渦流系統之動力特性呈現不穩定震盪現象。探究兩物體之渦流場，在主渦心之位置分佈上，翼形體較圓柱體稍靠近物體與平板交接處，且結果顯示主渦心分佈位置僅與物體之幾何形狀有關，而與雷諾數似乎無明顯關係。而兩物體之接面渦漩最大渦度值及總環流量均隨著雷諾數增加而增大；在相同雷諾數下，翼形體之接面渦旋總環流量低於圓柱體之總環流量。ABSTRACT A Particle Image Velocimetry（P.I.V.）techniques was used in a circulation water tank to measure the juncture vortex which is formed near the intersection of two different models ( circular cylinder and NACA0018) on a flat plate. Four cases with different Reynolds numbers were tested. The results show a vortex system occurs at the symmetry plane of the flow field. It was found the center of main vortex is no fixed. However no obvious relation was found between the center positions and Reynolds numbers. It showed that the main vortex centers are distributed closer to models in NACA0018 cases than in cylinder cases. Therefore, it is concluded that the model geometry affects the locations of main vortex center. Based on the measured velocity field, the vorticity and total circulations were calculated. It shows that the maximum vorticity and total circulation increase as Reynold number increases. It also found that the total circulations obtained in NACA0018 cases are smaller than in the cylinder cases.目 錄 ___________________________________________ 中文摘要 Ⅰ 英文摘要 Ⅱ 目錄 Ⅲ 圖目錄 Ⅵ 表目錄 Ⅹ 符號說明 ⅩI 第一章 緒論 1 1-1 研究動機………………….. …………………………...1 1-2 文獻回顧 3 1-3 本文組織 …………9 第二章 實驗設備佈置與方法 ..10 2-1 實驗設備 ………………………………………...…….....10 2-1.1 空蝕水槽……………………………………….....10 2-1.2 雷射.………………………………………………11 2-1.3 高速攝影機…………………….…………………11 2-1.4 光學透鏡組…………………………………….…12 2-1.5 懸浮顆粒…………………………………….……12 2-2實驗佈置及步驟……………………………………….13 2-2.1 實驗佈置……….……………………………..….13 2-2.2 實驗步驟…………..………………………….....15 第三章 影像分析及處理………………………….......21 3-1質點辨識…………………………….…….………………..21 3-2瞬時速度場分析……………………………….…………..23 3-2.1 應用相關運算原理之演算法……………………...24 3-2.2 應用類神經方法辨識質點運動………………….25 3-3流場渦度及環流量之分析……………..…….…………..28 3-4影像分析處理流程……..…………….……………………29 3-5渦心位置抓取之分析…..……………….………………...31 第四章 實驗結果與討論 …32 4-1 入流速度之率定 32 4-1.1入流速度之量測…………….………………………32 4-1.2入流端穩定流之量測………………………………36 4-2 接面渦漩之定性描述 40 4-2.1圓柱體之流場描述……….……………………..40 4-2.2 NACA0018翼形體之流場描述…………………..47 4-2.2渦旋中心變動分佈………………………………...49 4-3 接面渦漩之速度向量場分析 52 4-4接面渦漩之渦度場及環流量分析 59 4-4.1接面渦漩之渦度場分析……….…………………59 4-4.2接面渦漩之環流量分析…………………………...61 第五章 結論與未來展望 67 5-1 結論……………………………………………………….67 5-2 未來展望…………………………………………………..69 參考文獻…………………………………………… ….703190589 bytesapplication/pdfen-US接面渦漩,渦漩,圓柱體,粒子影像速度儀Juncture Vortex,Vortex,NACA0018,P.I.V,Cylinderthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51103/1/ntu-93-R91525007-1.pdf