潘國隆Pan, Kuo-Long臺灣大學:機械工程學研究所周秉忠Chou, Ping-ChungPing-ChungChou2010-06-302018-06-282010-06-302018-06-282008U0001-3001200817383200http://ntur.lib.ntu.edu.tw//handle/246246/187054不 同 表 面 張 力 水 溶 液 之 高 速 雙 液 滴 碰 撞秉忠導教授：潘國隆博士立台灣大學機械工程學研究所要 本文針對不同的溶液下所產生的液滴進行正向對撞，進而觀察其碰撞之現象，並且建立一套產生液滴之實驗設備，以及建立一套可觀測液滴撞擊現象的觀測設備，經由改變溶液的性質(表面張力)以及液滴大小與速度，並且藉由攝影所擷取的瞬間影像來了解液滴對撞之現象。實驗著重於二部份，第一，利用液滴產生器以及氣壓缸產生一穩定的低速以及高速液滴，並且能夠改變其成型的粒徑大小以及速度，第二，產生穩定液滴之後，進而使其對撞，對撞面必須為正向，且此二液滴的粒徑大小必須一樣，之後再觀察其現象。期望能夠提供液滴碰撞現象明確而且充分的資料。 過去前人對於液滴碰撞的研究雖然多，然而在之前的研究當中，其所探討之區域主要在較低韋伯數之區域，因此，本實驗主要在於能夠產生高速(高韋伯數)之液滴並且將其正向對撞。而本實驗的控制參數為液滴的性質(表面張力)、液滴大小與速度、噴嘴孔徑的大小、訊號產生器之電壓以及頻率、氣壓缸的壓力大小、馬達之轉速。 本實驗主要探討三個部份：一為在低速(低韋伯數)之下，液滴撞擊之現象觀察與討論；二為在高速(高韋伯數)之下，液滴撞擊之現象觀察與討論；三為更換不同的溶液，將表面張力改變，進而觀察其液滴撞擊的現象，而最後將實驗所得到之數據整理完整，之後再加以分析與比較其之間的差異。鍵字：液滴碰撞、液滴產生器、高速液滴、表面張力、韋伯數、訊號產生器High-Speed Binary Water Droplet Collision with Different Surface Tensioning-Chung Choudvisor：Kuo-Long Pan, Ph.D.epartment of Mechanical Engineeringational Taiwan Universitybstracthis study aims at droplet generation with different water solution to achieve a head-on collision and to observe the phenomenon under head-on collision. The set of devices for droplet generation and for observation of droplet collision are elaborated, through changing the parameters of solution (such as surface tension, size and velocity of droplets) and collecting the instant image by a high-speed camera to get more understanding of droplet collision phenomenon. In this experimental study, the most attention is given to two aspects. The first one is to generate a stable droplet with low and high speed respectively by using a droplet generator and a gas cylinder. At this stage we can control the size and velocity of a droplet. The second stage of experiment is to provide the droplet with head-on collision, whereby the size of two droplets must be almost the same, and then we observe the phenomenon. We expect to provide explicit and full data for droplet collision phenomena on this experiment. n spite of numerous researches on droplet collision, most of the research investigated into low Weber number of droplet. Therefore, this experiment is mainly focused on how to generate a high-speed (high Weber number) droplet and to make the droplet always keep head-on collision. The variables in this experiment include the droplet surface tension, the size and the velocity of droplet, the diameter of nozzle, the voltage and the frequency of signal generator, the pressure of gas cylinder, and the rotational speed of motor tested. he conclusions of this experiment consist of three parts. In the first part, we observe and discuss the collision of low velocity (low Weber number). The second is to describe the experimental results of high velocity (high Weber number) droplet collision. The third is to observe and discuss the phenomena of droplet collision under different surface tensions. eywords: droplet collision, droplet generator, high-speed droplet, surface tension, Weber number, signal generator.本 文 目 錄文摘要 ..............................I文摘要 ..............................III文目錄 ..............................V表目錄 ..............................VII號說明 ..............................XI 一 章 緒論..........................1-1前 言...............................1-2文獻回顧............................2-3研究動機及目的......................8 二 章 實驗設備裝置..................10-1液滴產生裝置........................10-1-1液滴產生方式......................10-1-2液滴產生器........................10-1-3電子控制裝置......................11-1-4噴嘴..............................12-1-5流體供應系統......................13-1-6液柱截斷裝置......................14-2影像拍攝系統........................15-3影像處理系統........................17-4其他測量設備........................17 三 章 實驗步驟與基礎理論............20-1實驗操作與拍攝......................20-1-1低速液滴對撞之操作................20-1-2高速液滴對撞之操作................21-1-3使用不同水溶液碰撞之操作..........23-2實驗數據讀取與分析..................24-3實驗數據之誤差分析..................25-4基礎理論............................26-4-1液滴拉伸斷裂理論..................26-4-2液柱噴流之斷裂理論................27-4-3液滴碰撞理論......................27 四 章 結 果 與 討 論................30-1結合................................31-2分離................................31-3分離後生成衛星液滴..................32-4指狀................................32-5指狀後分離..........................33-6破裂................................33-7飛濺................................34 五 章 結 論 與 未 來 發 展..........37 考 文 獻.........................39 表.............................43 表 目 錄 2-1 實驗設備之示意圖...............................43 2-2、2-3 實驗設備全貌實體圖........................44 2-4 液滴產生器.....................................45 2-5 液滴產生器與儲水瓶之相對位置...................45 2-6 電子控制箱.....................................46 2-7 不同大小之Nozzle 口徑..........................46 2-8 兩種不同 Nozzle 之比較.........................47 2-9 氣壓缸之管路配置實體圖.........................47 2-10 氣壓缸之動作圖 (引用自[42])...................48 2-11 馬達以及轉盤之實體圖..........................48 2-12 轉盤之切口....................................49 2-13 CCD攝影機與 NAVIYAR 鏡頭......................49 2-14 電視影像擷取介面卡............................50 2-15 高速攝影機與 Nikon 之鏡頭.....................50 2-16 投影機燈......................................51 2-17 高速攝影機與 Computar MLH-10X 之鏡頭..........51 2-18 同步LED燈.....................................52 2-19 高速攝影機之操作使用介面......................52 2-20 MATROX 操作使用介面...........................53 2-21 表面張力測量儀................................53 2-22 黏度計........................................54 2-23 電子秤........................................54 2-24 界面活性劑....................................55 2-25 超音波震盪器..................................55 3-1 a、b表面張力72之切過長與切過短之液柱變化圖.....56 3-1 c、d表面張力72之8.7a與12a之液柱變化圖..........57 3-2 a、b表面張力16之切過長與切過短之液柱變化圖.....58 3-2 c、d表面張力16之7.5a與9a之液柱變化圖...........59 3-3 a、b表面張力31之切過長與切過短之液柱變化圖.....60 3-3 c、d表面張力31之8a與9.5a之液柱變化圖...........61 3-4 液滴拉伸斷裂實體圖.............................62 3-5 液滴拉伸斷裂機制圖 (引用自[34])................62 3-6 液柱直徑、擾動波長，液滴尺寸之關係 (引用自[41])63 3-7 液滴撞擊之模型圖 (引用自[31])..................63 3-8 水滴碰撞現象與對應韋伯數與撞擊參數之關係.......64 4-1 液滴撞擊現象與相對應之韋伯數與表面張力之關係...65 4-2 各區域在不同表面張力之劃分圖...................66 4-3純水在We=16.2下之液滴撞擊時序圖.................67 4-4表面張力31在We=44.9下之液滴撞擊時序圖...........68 4-5表面張力16在We=46.0下之液滴撞擊時序圖...........69 4-6液滴撞擊產生分離(separation)現象之示意圖........70 4-7純水在We=36.5下之液滴撞擊時序圖.................71 4-8表面張力31在We=86.7下之液滴撞擊時序圖...........72 4-9表面張力16在We=123.4下之液滴撞擊時序圖..........73 4-10純水在We=45.3下之液滴撞擊時序圖................74 4-11表面張力31在We=147.7下之液滴撞擊時序圖.........75 4-12表面張力16在We=168.1下之液滴撞擊時序圖.........76 4-13純水在We=108.9下之液滴撞擊時序圖...............77 4-14表面張力31在We=872.7下之液滴撞擊時序圖.........78 4-15表面張力16在We=660.7下之液滴撞擊時序圖.........79 4-16純水在We=210.2下之液滴撞擊時序圖...............80 4-17表面張力31在We=1236.2下之液滴撞擊時序圖........81 4-18表面張力16在We=2268.8下之液滴撞擊時序圖........82 4-19純水在We=277.3下之液滴撞擊時序圖...............83 4-20表面張力31在We=1444.8下之液滴撞擊時序圖........84 4-21表面張力16在We=2487.3下之液滴撞擊時序圖........85 4-22純水在We=252.4之盤狀擴散飛濺過程...............86 4-23表面張力31在We=1444.8之盤狀擴散飛濺過程........87 4-24表面張力16在We=2460.9之盤狀擴散飛濺過程........88 4-25純水在We=877.5下之液滴撞擊時序圖...............89 4-26表面張力31在We=2257.5下之液滴撞擊時序圖........90 4-27表面張力16在We=3326.7下之液滴撞擊時序圖........91 4-28純水在We=371.2之盤狀擴散飛濺過程...............92 4-29表面張力31在We=1716.6之盤狀擴散飛濺過程........93 4-30表面張力16在We=2800.0之盤狀擴散飛濺過程........94 4-31純水在We=442.3之盤狀擴散飛濺過程...............95 4-32純水在We=650.0之盤狀擴散飛濺過程...............96 4-33純水在We=805.2之盤狀擴散飛濺過程...............97 4-34表面張力31在We=1923.2之盤狀擴散飛濺過程........98 4-35表面張力31在We=2141.6之盤狀擴散飛濺過程........99 4-36表面張力16在We=3160.9之盤狀擴散飛濺過程........100 4-37表面張力16在We=4032.0之盤狀擴散飛濺過程........101 4-38純水在We=972.3之盤狀擴散飛濺過程...............102 4-39純水在We=1176.5之盤狀擴散飛濺過程..............103 4-40表面張力31在We=2371.8之盤狀擴散飛濺過程........104 4-41表面張力31在We=2488.9之盤狀擴散飛濺過程........105 4-42表面張力16在We=4375.0之盤狀擴散飛濺過程........106 4-43表面張力16在We=4823.4之盤狀擴散飛濺過程........107 4-44純水在We=1519.2之盤狀擴散飛濺過程..............108 4-45表面張力31在We=2731.6之盤狀擴散飛濺過程........109 4-46表面張力16在We=5293.8之盤狀擴散飛濺過程........110 4-47純水在We=1593.0下之液滴撞擊時序圖..............111 4-48表面張力31在We=2731.6下之液滴撞擊時序圖........112 4-49表面張力16在We=5293.8下之液滴撞擊時序圖........113 4-50純水在We=5143.5下之液滴撞擊時序圖..............114 4-51表面張力31在We=6146.0下之液滴撞擊時序圖........115 4-52表面張力16在We=7393.8下之液滴撞擊時序圖........116 4-53不同表面張力下韋伯數(We)與盤狀寬度(W)之關係....117 4-54韋伯數與歐式數在分離現象分界之關係.............118 4-55韋伯數與歐式數在區域分界之關係.................118 一 兩種界面活性劑之性質............................119 二 噴嘴口徑與形成之液滴大小之關係..................120 三 表面張力值與截斷長度之關係比較..................120 四 在各表面張力值之各現象分佈區域..................120錄一................................................121錄二................................................12218297616 bytesapplication/pdfen-US液滴碰撞液滴產生器高速液滴表面張力韋伯數訊號產生器droplet collisiondroplet generatorhigh-speed dropletsurface tensionWeber numbersignal generatorthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/187054/1/ntu-97-R94522317-1.pdf