納米流體靜電霧化特性的實驗研究
發(fā)布時間：2018-08-03 07:44
【摘要】：隨著電子產(chǎn)品的發(fā)展,芯片集成化程度越來越高,在微米級尺度上對芯片進行散熱是極具挑戰(zhàn)性的課題。高效導熱薄膜材料為芯片散熱問題的解決提供了新思路。近年來,采用納米流體的靜電霧化沉積制備高效導熱薄膜材料逐漸引起了國內(nèi)外學者的關注。納米流體因其自身物理性質(zhì)的特異性,其靜電霧化特性區(qū)別于普通流體,深入了解納米流體靜電霧化特性并探索其破碎機制可為發(fā)展高效薄膜制備技術奠定理論基礎�；诖�,本文對納米流體的靜電霧化特性進行了基礎性的實驗研究,主要工作如下:采用顯微高速數(shù)碼攝像技術對納米流體的靜電霧化模式轉(zhuǎn)變進行了可視化研究。以不同組份的納米流體為研究介質(zhì),精確捕捉了不同工況下納米流體霧化形態(tài)的演變行為;探索了質(zhì)量分數(shù)及流量等因素對納米流體霧化模式轉(zhuǎn)變的影響。實驗結(jié)果表明:隨著質(zhì)量分數(shù)的升高,納米流體的錐射流模式區(qū)間逐漸縮小,過渡到錐射流狀態(tài)的臨界電場強度逐漸增大,而電導率的升高使得納米流體更易過渡到多股射流模式。流量的增加削弱了霧化的穩(wěn)定性,形成錐射流及多股射流所需的電場強度越高。繪制了電場強度和流量影響下特定組份納米流體的霧化模式圖,為探索和發(fā)展薄膜材料的制備技術奠定了基礎�；诩{米流體靜電霧化模式的轉(zhuǎn)變規(guī)律,對各霧化模式下的液滴沉積分布特性進行了實驗研究。實驗結(jié)果表明:隨著電壓的增大,液滴粒徑呈減小趨勢,滴狀模式下液滴粒徑呈指數(shù)減小;錐射流模式下液滴粒徑呈線性減小;多股射流模式下液滴粒徑變化較為復雜。流量的降低可使液滴粒徑有所減小,但液滴粒徑減小并不明顯;流量降低后,液滴粒徑分布較寬,小粒徑液滴所占比例有所升高。對不同組份納米流體荷電液滴在氣動作用下的變形破碎特性進行了實驗研究。結(jié)果表明:荷電液滴袋狀破碎過程;中隨著納米顆粒質(zhì)量分數(shù)的增加,荷電液滴袋的生長及袋的破碎所需時間逐漸減少;高荷電量的乙醇液滴與低荷電量的石墨-乙醇納米流體液滴在破碎過程中,破碎所需時間以及形態(tài)都極其類似,這表明納米顆粒的加入促進了氣動作用下荷電液滴袋狀破碎的進程。
[Abstract]:With the development of electronic products, the integration of chips is becoming more and more high. High-efficiency thermal conductive thin-film materials provide a new way to solve the problem of chip heat dissipation. In recent years, the preparation of high efficiency thermal conductivity thin films by electrostatic atomization deposition of nanofluids has gradually attracted the attention of scholars at home and abroad. The electrostatic atomization property of nano-fluid is different from that of ordinary fluid because of its own specific physical properties. Understanding the electrostatic atomization characteristics of nano-fluid and exploring its crusher can lay a theoretical foundation for the development of high-efficiency thin film preparation technology. Based on this, the basic experimental study of electrostatic atomization characteristics of nano-fluid is carried out in this paper. The main work is as follows: the visualization study of electrostatic atomization mode transformation of nano-fluid is carried out by using micro-high-speed digital camera technology. The evolution behavior of nano-fluid atomization morphology under different working conditions was accurately captured with different components of nano-fluid as the research medium, and the effects of mass fraction and flow rate on the transformation of nano-fluid atomization mode were explored. The experimental results show that with the increase of mass fraction, the range of conical jet mode of nano-fluid gradually decreases, and the critical electric field intensity of transition to cone-jet state increases gradually. The increase of conductivity makes it easier for nanoscale fluid to transition to multi-strand jet mode. With the increase of flow rate, the stability of atomization is weakened, and the electric field intensity required for the formation of conical jet and multi-jet is higher. The atomization mode diagram of nano-fluids with specific components under the influence of electric field intensity and flow rate was drawn, which laid a foundation for exploring and developing the preparation technology of thin film materials. Based on the transformation rule of electrostatic atomization mode of nano-fluid, the deposition distribution characteristics of droplets in different atomization modes were studied experimentally. The experimental results show that the droplet size decreases with the increase of voltage, decreases exponentially in droplet mode, linearly decreases in cone-jet mode, and complex in multi-strand jet mode. When the flow rate decreases, the droplet size decreases, but the droplet size decreases not obviously. After the flow rate decreases, the droplet size distribution is wider, and the ratio of small droplet size increases. The characteristics of deformation and breakage of charged droplets with different components under aerodynamic action were investigated experimentally. The results show that the growth of charged droplet bags and the time required to break them decrease with the increase of the mass fraction of nanoparticles. The breakage time and morphology of high-charge ethanol droplets and low-charge graphite-ethanol nano-fluid droplets are very similar. This indicates that the addition of nanoparticles promotes the process of charged droplet bag breakage under pneumatic action.
【學位授予單位】：江蘇大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TB383.1
本文編號：2161074
[Abstract]:With the development of electronic products, the integration of chips is becoming more and more high. High-efficiency thermal conductive thin-film materials provide a new way to solve the problem of chip heat dissipation. In recent years, the preparation of high efficiency thermal conductivity thin films by electrostatic atomization deposition of nanofluids has gradually attracted the attention of scholars at home and abroad. The electrostatic atomization property of nano-fluid is different from that of ordinary fluid because of its own specific physical properties. Understanding the electrostatic atomization characteristics of nano-fluid and exploring its crusher can lay a theoretical foundation for the development of high-efficiency thin film preparation technology. Based on this, the basic experimental study of electrostatic atomization characteristics of nano-fluid is carried out in this paper. The main work is as follows: the visualization study of electrostatic atomization mode transformation of nano-fluid is carried out by using micro-high-speed digital camera technology. The evolution behavior of nano-fluid atomization morphology under different working conditions was accurately captured with different components of nano-fluid as the research medium, and the effects of mass fraction and flow rate on the transformation of nano-fluid atomization mode were explored. The experimental results show that with the increase of mass fraction, the range of conical jet mode of nano-fluid gradually decreases, and the critical electric field intensity of transition to cone-jet state increases gradually. The increase of conductivity makes it easier for nanoscale fluid to transition to multi-strand jet mode. With the increase of flow rate, the stability of atomization is weakened, and the electric field intensity required for the formation of conical jet and multi-jet is higher. The atomization mode diagram of nano-fluids with specific components under the influence of electric field intensity and flow rate was drawn, which laid a foundation for exploring and developing the preparation technology of thin film materials. Based on the transformation rule of electrostatic atomization mode of nano-fluid, the deposition distribution characteristics of droplets in different atomization modes were studied experimentally. The experimental results show that the droplet size decreases with the increase of voltage, decreases exponentially in droplet mode, linearly decreases in cone-jet mode, and complex in multi-strand jet mode. When the flow rate decreases, the droplet size decreases, but the droplet size decreases not obviously. After the flow rate decreases, the droplet size distribution is wider, and the ratio of small droplet size increases. The characteristics of deformation and breakage of charged droplets with different components under aerodynamic action were investigated experimentally. The results show that the growth of charged droplet bags and the time required to break them decrease with the increase of the mass fraction of nanoparticles. The breakage time and morphology of high-charge ethanol droplets and low-charge graphite-ethanol nano-fluid droplets are very similar. This indicates that the addition of nanoparticles promotes the process of charged droplet bag breakage under pneumatic action.
【學位授予單位】：江蘇大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TB383.1
【參考文獻】
相關期刊論文 前10條
1 王貞濤;張永輝;Sau Amalendu;夏磊;詹水清;;雙毛細管靜電霧化電場特性研究[J];農(nóng)業(yè)機械學報;2016年12期
2 崔海蓉;楊超珍;余盛兵;周佳標;;電極參數(shù)影響射流噴霧荷電量的試驗研究[J];高電壓技術;2015年12期
3 王軍鋒;顧維鍇;王曉英;儲進靜;;感應荷電噴霧荷電性能與噴霧特性試驗研究[J];高電壓技術;2015年02期
4 王軍鋒;左子文;霍元平;;液滴演化及靜電場下錐射流形成的數(shù)值模擬[J];工程熱物理學報;2013年04期
5 霍元平;王軍鋒;毛文龍;王澤;左子文;;荷電液滴脈動變形特性的實驗研究[J];工程熱物理學報;2013年01期
6 段洪斌;王大志;梁軍生;劉沖;;C納米懸浮液的電流體驅(qū)動霧化研究[J];中國科技論文在線;2010年08期
7 王貞濤;聞建龍;王曉英;羅惕乾;;高壓靜電液體霧化技術[J];高電壓技術;2008年05期
8 羅惕乾;王曉英;鄭捷慶;王貞濤;毛惠敏;;氣流中荷電液滴破碎數(shù)值模擬[J];排灌機械;2007年02期
9 張軍;聞建龍;王軍鋒;羅惕乾;;毛細管環(huán)電極下的靜電霧化模式的研究[J];農(nóng)業(yè)機械學報;2006年06期
10 于水,李理光,胡宗杰,鄧俊,栗工;靜電噴霧液滴破碎的理論邊界條件研究[J];內(nèi)燃機學報;2005年03期
相關博士學位論文 前2條
1 霍元平;荷電液滴破碎機理及電流體動力學特性研究[D];江蘇大學;2015年
2 朱海濤;納米流體的制備、穩(wěn)定及導熱性能研究[D];山東大學;2005年
相關碩士學位論文 前4條
1 巴政宇;基于電霧化技術的導電顆粒布控工藝研究與開發(fā)[D];上海交通大學;2015年
2 馬乾;石墨烯微結(jié)構(gòu)的電霧化沉積和電射流直寫成型研究[D];大連理工大學;2014年
3 李景良;電霧化液滴運行軌跡仿真及沉積實驗研究[D];大連理工大學;2013年
4 毛惠敏;靜電霧化沉積制備薄膜材料的研究[D];江蘇大學;2007年
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