本文選題：非牛頓流體 + 氣泡運動　； 參考：《大連理工大學》2016年碩士論文

【摘要】：非牛頓流體中的氣泡運動行為廣泛存在于石油化工、環(huán)境保護、能源開發(fā)及利用等工程領(lǐng)域。由于非牛頓流體特殊的流變性質(zhì)以及氣液兩相之間相互作用的復雜性,對于非牛頓流體中的單氣泡生成、上升以及雙氣泡聚并行為的研究目前仍不夠完善。本文做了以下工作：(1)采用高速攝影技術(shù)以及數(shù)字圖像處理技術(shù)對去離子水和不同濃度CMC水溶液中單氣泡的生成及上升運動進行實驗研究,考察了單氣泡的形成過程,討論了氣泡上升過程當量直徑、運動軌跡及運動速度的變化規(guī)律。研究發(fā)現(xiàn),單氣泡的形成過程可細分為三個階段。在去離子水及CMC水溶液中,氣泡的平均當量直徑、擺動幅度以及擺動的隨機性受噴嘴內(nèi)徑及CMC水溶液濃度的影響較大。在去離子水中,氣泡先呈直線上升,當z28mm時,氣泡開始振蕩,呈螺旋形上升；而在CMC水溶液中,氣泡運動軌跡幾乎均呈直線。隨著CMC水溶液濃度的增加,進氣流量的降低,氣泡水平速度的波動及氣泡垂直速度逐漸減小。隨著噴嘴內(nèi)徑的增大,CMC水溶液中氣泡水平速度的波動變大,同時高濃度CMC水溶液中氣泡的垂直速度也隨之增大,但對低粘度溶液中運動氣泡的垂直速度的影響并不明顯。此外,建立了在一定無量綱參數(shù)數(shù)值范圍內(nèi),適用于去離子水與CMC水溶液中,氣泡的Rｅ與We、Mo之間的函數(shù)關(guān)系式。(2)采用FLUENT軟件,基于流體體積法(VOF)對單氣泡生成及上升運動進行數(shù)值模擬,并與實驗結(jié)果進行對比分析,進而研究氣泡周圍液相場的特點。研究了單氣泡形成過程中氣泡及其周圍液相壓力場和速度場的分布規(guī)律,并重點對CMC水溶液中上升氣泡周圍液相速度場的影響因素進行討論分析。隨著CMC水溶液濃度的升高,氣泡周圍液體運動速度降低,氣泡的影響區(qū)減�。欢S著進氣流量及噴嘴內(nèi)徑的增加,氣泡周圍液體速度增加,氣泡影響區(qū)域變寬變長。(3)采用高速攝影對平行雙氣泡的生長聚并過程進行實驗研究并與數(shù)值模擬結(jié)果對比。結(jié)果表明,雙氣泡的生長及聚并過程可分為四個階段。重點分析平行雙氣泡聚并前后氣泡縱橫比變化的影響因素。氣泡聚并之前,氣泡縱橫比會隨著進氣流量、噴嘴內(nèi)徑的增加而分別升高和降低。在較低氣量、較大噴嘴內(nèi)徑以及大噴嘴間距的情況下,平行雙氣泡較晚發(fā)生聚并。氣泡聚并之后,隨著進氣流量、噴嘴內(nèi)徑的增大及噴嘴間距的減小,氣泡縱橫比增大,且整個過程中CMC溶液濃度對聚并過程的影響都較為微弱。
[Abstract]:Bubble motion behavior in non-Newtonian fluids is widely used in petrochemical engineering, environmental protection, energy development and utilization. Due to the special rheological properties of non-Newtonian fluids and the complexity of the interaction between gas-liquid phases, the studies on the formation, rise and aggregation of double bubbles in non-Newtonian fluids are still insufficient. In this paper, the following works have been done: (1) the formation and rising motion of a single bubble in deionized water and CMC aqueous solution with different concentrations have been studied experimentally by using high-speed photography and digital image processing technology, and the formation process of single bubble has been investigated. The changes of equivalent diameter, trajectory and velocity of bubble rising are discussed. It is found that the formation process of single bubble can be divided into three stages. In deionized water and CMC aqueous solution, the average equivalent diameter, swing amplitude and randomness of the bubble are greatly affected by the inner diameter of the nozzle and the concentration of CMC aqueous solution. In the deionized water, the bubbles first rise in a straight line, and when the bubbles begin to oscillate, the bubbles rise in a spiral shape, while in the aqueous solution of the z28mm, the trajectory of the bubbles is almost in a straight line. With the increase of CMC aqueous solution concentration and the decrease of inlet air flow rate, the fluctuation of bubble horizontal velocity and bubble vertical velocity gradually decrease. With the increase of nozzle diameter, the fluctuation of the horizontal velocity of bubbles in CMC aqueous solution becomes larger, and the vertical velocity of bubbles in high concentration CMC aqueous solution increases, but the effect on the vertical velocity of moving bubbles in low viscosity solution is not obvious. In addition, a functional relationship between re and Weimo of bubbles in deionized water and CMC aqueous solution in a certain dimensionless parameter range is established. (2) fluent software is used. Based on the fluid volume method (VOF), the formation and rising motion of a single bubble are numerically simulated, and compared with the experimental results, the characteristics of the liquid field around the bubble are studied. The distribution of pressure field and velocity field of liquid phase during the formation of a single bubble is studied, and the factors affecting the velocity field of liquid phase around a rising bubble in CMC aqueous solution are discussed. With the increase of CMC concentration, the velocity of the liquid around the bubble decreases and the influence zone of the bubble decreases, while the velocity of the liquid around the bubble increases with the increase of the inlet air flow rate and the inner diameter of the nozzle. (3) High-speed photography was used to study the growth and coalescence process of parallel double bubbles, and the results were compared with the numerical simulation results. The results show that the growth and coalescence of double bubbles can be divided into four stages. The influence factors of the aspect ratio of the bubbles before and after the parallel double bubbles are analyzed. Before bubble coalescence, the aspect ratio of bubble increases and decreases with the increase of inlet flow rate and nozzle diameter. Under the conditions of lower gas flow, larger nozzle diameter and larger nozzle spacing, the parallel double bubbles converge later. After bubble coalescence, with the increase of inlet air flow rate, the increase of nozzle inner diameter and the decrease of nozzle spacing, the aspect ratio of bubble increases, and the concentration of CMC solution has a weak effect on the coalescence process in the whole process.
【學位授予單位】：大連理工大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TQ021.1

【參考文獻】

相關(guān)期刊論文 前10條

1 宮大鑫;黃善仿;王侃;王扶月;周鈴嵐;;基于計算流體動力學的矩形通道內(nèi)氣泡運動機理研究[J];核動力工程;2014年03期

2 翟甜;郝惠娣;高利博;雷建勇;;鼓泡塔氣液兩相流內(nèi)部流場的流體力學特性[J];化工進展;2013年10期

3 陳汗青;萬艷玲;王國剛;;數(shù)字圖像處理技術(shù)研究進展[J];工業(yè)控制計算機;2013年01期

4 劉海燕;龐明軍;魏進家;;非牛頓流體研究進展及發(fā)展趨勢[J];應用化工;2010年05期

5 張淑君;吳錘結(jié);;氣泡之間相互作用的數(shù)值模擬[J];水動力學研究與進展A輯;2008年06期

6 徐炯;王彤;楊波;谷傳綱;王煥然;;靜止水下氣泡運動特性的測試與分析[J];水動力學研究與進展A輯;2008年06期

7 李光;楊曉鋼;戴干策;;鼓泡塔反應器氣液兩相流CFD數(shù)值模擬[J];化工學報;2008年08期

8 陳致泰;李世剛;韓光瑤;謝有暢;;微氣泡純氧曝氣技術(shù)用于河湖復氧治理[J];水科學與工程技術(shù);2008年01期

9 張果;李曉娟;張憲;;基于迭代閾值和形態(tài)學的圖像邊緣檢測[J];微計算機信息;2007年27期

10 范文元;朱春英;馬友光;余國琮;;非牛頓流體中的氣泡行為[J];化學工業(yè)與工程;2006年05期

相關(guān)會議論文 前1條

1 郭艷利;孫寶江;王寧;范志;左坤;;單個氣泡在井筒內(nèi)上升速度規(guī)律實驗研究[A];第十三屆全國水動力學學術(shù)會議暨第二十六屆全國水動力學研討會論文集——D水動力學實驗和測試技術(shù)[C];2014年

相關(guān)博士學位論文 前2條

1 李少白;非牛頓流體中氣泡運動及傳質(zhì)的研究[D];天津大學;2011年

2 王紅一;水中氣泡圖像處理方法及運動特性研究[D];天津大學;2011年

相關(guān)碩士學位論文 前2條

1 馬斗;單孔氣泡動力學行為的VOF數(shù)值模擬[D];天津大學;2009年

2 楊珂;氣泡在非牛頓流體中的運動行為及流場特性[D];天津大學;2008年

，

本文編號：2061436