https://scholars.lib.ntu.edu.tw/handle/123456789/67918
標題: | 雙液滴碰撞:一、偏心碰撞的再研究
二、加入界面活性劑Span 80對雙油滴碰撞的影響 Binary droplet collision: 1. Off-center separation revisited 2. Surfactant(Span 80) effect on collision behavior of hydrocarbon fuels |
作者: | 呂季儒 Lu, Chi-Ru |
關鍵字: | 液滴碰撞;偏心碰撞分離;烷類液滴;液滴碰撞型態;界面活性劑;Span 80;droplet collision;off-center separation;hydrocarbon droplets;droplet collision outcomes;surfactant | 公開日期: | 2011 | 摘要: | 本研究首先以雙液滴碰撞為主軸,以液滴偏心 碰撞分離機制與型態為研究重點,改進實驗觀測方式,並且以三種純烷類以及三種Span 80/十四烷混和溶液為實驗流體研究雙液滴碰撞行為。研究結果發現烷類流體的液滴碰撞型態共可歸類為六種,分別為(I)液滴輕微變形後結合、(II)碰撞彈開、(III)液滴顯著變形後結合、(IV)一次反射分離、(V) 拉伸分離 和(VI) 二次反射分離。並在研究中利用現有液滴碰撞分離機制,再另外加入適當假設,說明二次反射分離中液滴型態與分離的機制。在論文的第二個部分我們利用正撞分離臨界韋伯數分析,以及矽油/烷類混和溶液驗證,說明將Span 80加入烷類溶劑,除了增加黏滯性外,並無其他巨觀效應影響液滴碰撞現象。最後利用不同黏滯性Span 80/烷類溶液在正撞彈開時的臨界韋伯數做出推論,當黏滯性上升時,正撞彈開之臨界韋伯數升高,但此效應將隨黏滯性逐步提高而消弭。 An experimental investigation of binary droplet collision dynamics was conducted, with emphasis on the off-center separation outcomes and surfactant effect on collision behavior of hydrocarbon fuels. First, six kinds of hydrocarbon fluid and Span 80/hydrocarbon fluid were used in the experiment. The results show that collision outcomes of hydrocarbon droplets exhibit six distinct regimes, namely (I) coalescence after minor deformation, (II) bouncing, (III) coalescence after substantial deformation, (IV) reflective separation, (V) stretching separation and, (VI) second reflexive separation. Then we base on a basic droplet collision model with some assumption properly to explain the second reflexive separation. The other part of the study, we will analyze the critical Weber number of the Span 80 /hydrocarbon and silicone oil /hydrocarbon to prove that viscosity is the only factor affected by Span 80. Finally, we conclude that higher viscosity will promote droplet bouncing but become trivial as it reaches a critical value. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/255888 |
顯示於: | 機械工程學系 |
檔案 | 描述 | 大小 | 格式 | |
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ntu-100-R98522317-1.pdf | 23.54 kB | Adobe PDF | 檢視/開啟 |
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