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研究生:王相爲
研究生(外文):Hsiang-WeiWang
論文名稱:電液動技術應用於自然對流之熱增強及最佳化分析
論文名稱(外文):Heat Transfer Enhancement and Optimization Analysis of Natural Convection with Electrohydrodynamic Technology
指導教授:張錦裕張錦裕引用關係
指導教授(外文):Jiin-Yuh Jang
學位類別:碩士
校院名稱:國立成功大學
系所名稱:機械工程學系
學門:工程學門
學類:機械工程學類
論文種類:學術論文
論文出版年:2020
畢業學年度:108
語文別:中文
論文頁數:122
中文關鍵詞:電液動技術自然對流熱增強最佳化分析
外文關鍵詞:EHDNatural convectionHeat transfer enhancementOptimization analysis
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本研究透過數值模擬研究線狀電極電液動(EHD,Electrohydrodynamic)技術應用於自然對流的熱增強及最佳化分析。以二維紊流模型探討三種自然對流系統:側邊加熱之封閉矩形(case A)、底部加熱之封閉矩形(case B)和底部加熱之無限長水平板(case C),在不同施加電壓、溫差、電極高度及電極數(電極間距)下,電液動所產生的熱增強效果,並考慮焦耳熱效應對溫度場及熱傳增強的影響。
在側邊加熱(case A)及底部加熱(case B)之封閉矩形中,增加施加電壓可以有效提升熱傳增益;當電極數(N=1-6)增加時,會造成流場中的渦流數增加和電極產生的焦耳熱效應增強;隨電極高度(HEHD=10-40mm)改變,當電極高度位在右半部(上半部)會有最大紐賽數比。由於EHD為主動式熱增強方式,因而需考慮施加的功率Power並定義單位功耗之淨熱傳增強量(QEHD-Q0)/Power作為衡量熱增強效率的標準。在特定的施加電壓V0 (12、13和14kV)及溫差∆T (20、25和30K)下,透過參數分析可以得到最佳(QEHD-Q0)/Power及其對應的電極數(N)和電極高度(HEHD)組合。
在底部加熱之水平無限長平板(case C)中,增加施加電壓可以有效提升熱傳增益;隨電極間距或電極高度改變,紐賽數比存在最佳值。在熱增強的最佳化研究中,利用簡易共軛梯度法執行最佳化搜尋,並以(QEHD-Q0)/Power為目標函數,藉由電極高度(HEHD)和電極間距(SL)的變化,搜尋目標函數的最大值,其搜尋範圍分別為10mm 〈 HEHD 〈 40mm和50mm 〈 SL 〈 90mm。結果顯示,在特定施加電壓V0 (12、13和14kV)及溫差∆T (20、25和30K)下,可以得到最佳(QEHD-Q0)/Power及其對應的電極高度(HEHD)和電極間距(SL)組合。
The paper studied the wire electrodes EHD effect on the heat transfer enhancement by numerical method. There were three type of physical models, enclosure heat from side (case A), enclosure heated from below (case B) and infinite horizontal plates heated from below (case C). Two-dimensional turbulent models for the prediction of heat transfer enhancement with different applied voltage, number of electrodes, electrode pitch and electrode height were investigated and evaluated the effects of Joule heating on heat transfer performance. The result shows that the heat transfer enhancement increases as the applied voltage increases. The number of vortices in the flow field increases with the increase in number of electrodes. Furthermore, the power consumption was also taken into account, and the net heat transfer enhancement per unit power consumption (QEHD-Q0)/Power was taken as the objective function. The maximum objective function value and the optimal electrode arrangement were obtained with specified V0 (12, 13 and 14 kV) and specified ∆T (20, 25 and 30 K) by numerical analysis or optimal strategy (SCGM, simplified conjugate gradient method).
摘要 II
Abstract III
誌謝 IX
目錄 X
圖目錄 XII
表目錄 XVII
符號說明 XVIII
緒論 1
1.1前言 1
1.2文獻回顧 2
1.3研究動機與目的 7
第二章 理論分析 9
2.1物理模型 9
2.2基本假設 10
2.3統御方程式 11
2.4紐賽數Nu及瑞利數Ra之計算 14
2.5單位功耗之淨熱傳增加量 15
2.6邊界條件 16
第三章 最佳化理論與數值分析 24
3.1最佳化理論 24
3.1.1共軛梯度法 24
3.1.2簡易共軛梯度法 26
3.1.3最佳化執行流程 26
3.1.4目標函數定義 28
3.2數值方法 28
3.2.1通用守恆方程式(Generic Conservation Equation) 29
3.2.2有限體積法(Finite Volume Method,FVM) 29
3.2.3SIMPLEC演算法 32
3.2.4電場統御方程式之離散 34
3.2.5邊界條件之離散 35
3.3格點測試 36
3.4電極處電荷密度 37
第四章 結果與討論 52
4.1電荷密度分布 52
4.2焦耳熱對熱傳增益的影響 52
4.3電液動技術於封閉矩形空間之熱傳增強分析 53
4.3.1側邊加熱之封閉矩形空間(Case A) 54
4.3.2底部加熱之封閉矩形空間(Case B) 58
4.4電液動技術於無限長水平板之熱傳增強最佳化分析 103
第五章 結論 116
5.1電液動技術應用於側邊及底部加熱之封閉矩形 116
5.2電液動技術應用於底部加熱之無限長水平板 118
參考文獻 120
【1】Chandrasekher,S., “Hydrodynamic and hydromagnetic stability, Oxford University Press, London, 1961.
【2】Drazin, P.G. and Reid, W.H., “Hydrodynamic stability, Cambridge University Press, London, 1981.
【3】Jang, J.Y., Chou, W.C., and Leu,J.S., “Natural convection in fluid/porous region heated from below with conductive partition Journal of Thermophysics and Heat Transfer, Vol. 26, No. 2, 2012.
【4】Allen, P.H.G. and Karayiannis, T.G., “Electrohydrodynamic enhancement of heat transfer and fluid flow,Heat Recovery Systems & CHP, Vol. 15, No. 5, pp. 389-423., 1995.
【5】Yabe, A., Mori, Y. and Hijikata, K., “EHD study of the corona wind between wire and plate electrodes, AIAA Journal, Vol. 16, No. 4, pp. 340-345., 1978.
【6】Sheu, W.J., Hsiao, J.J. and Wang, C.C., “Effect of oscillatory EHD on the heat transfer performance of a flat plate, International Journal of Heat and Mass Transfer, Vol. 61, pp. 419-424., 2013.
【7】Kiber, K.G. and Carter, H.G., “Electrocooling in gases, Journal of Applied Physics,Vol. 45, pp.4436-4440.,1974
【8】O’Brien, R.J. and Shine, A.J., “Some effects of an electric field on heat transfer from a vertival plate in free convection, ASME, Vol.89, pp.114-116., 1967.
【9】Owsenek, B.L. and Seyed-Yagoobi, J., “Theoretical and experimental study of electrohydrodynamic heat transfer enhancement through wire-plate corona discharge, Journal of Heat Transfer, Vol. 119, pp. 604-610., 1997.
【10】Franke, M.E., “Discharge on free-convection heat transfer from a vertival plate, Journal of Heat Transfer, Vol. 91, No. 3, pp. 427-432., 1969.
【11】Ohadi, M.M., Nelson, D.A. and Zia, S., “Heat transfer enhancement of laminar and turbulent pipe flow via corona discharge, International Journal of Heat and Mass Transfer, Vol. 34, No. 4-5, pp.1175-1187., 1991.
【12】Franke, M.E. and Hutson, K.E., “Effects of corona discharge on free-convection heat transfer inside a vertical hollow cylinder, Journal of Heat Transfer, Vol. 106, pp. 346-351., 1984.
【13】Kasayapanand, N. and Kiatsiriroat, T., “EHD enhanced heat transfer in wavy channel, International Communication in Heat and Mass Transfer, Vol. 32, pp.809-821., 2005.
【14】Fernandez, J.L. and Poulter, R., “Radial mass flow in electrohydrodynamically enhanced forced heat transfer in tubes, International Journal of Heat and Mass Transfer, Vol. 30, No. 10, pp. 2125-2136., 1987.
【15】Haung, M., and Lai, F.C., “Effects of Joule Heating on Electrohydrodynamics-Enhanced Natural Convection in an enclosure, Journal of Thermophysics and Heat Transfer, Vol. 20, No. 4, pp. 939-945, 2006.
【16】Fujino, T., Yokoyama, Y. and Mori, Y.H., “Augmentation of Laminar Forced-Convection Heat Transfer by the Application of Transverse Electric Field, Journal of Heat Transfer, Vol. 111, pp. 345-351., 1989.
【17】Peng, M., Wang, T.H. and Wang, X.D., “Effect of longitudinal electrode arrangement on EHD-induced heat Transfer enhancement in a rectangular channel, International Journal of Heat and Mass Transfer, Vol. 93, pp. 1072-1081., 2016.
【18】Owsenek, B.L., Seyed-Yagoobi, J. and Page, R.H., “Experimental Investigation of Corona Wind Heat Transfer Enhancement With a Heated Horizontal Flat Plat, Journal of Heat Transfer, Vol. 117, pp. 309-315., 1995.
【19】Lai, F.C. and Mathew, J., “Heat Transfer Enhancement by EHD-Induced Oscillatory Flows, Journal of Heat Transfer, Vol. 128, No. 9, pp. 861-869., 2006.
【20】Kasayapanand, N., “Electrode arrangement effect on natural convection, Energy Conversion and Management, Vol. 48, No. 4, pp. 1323-1330., 2007.
【21】Kasayapanand, N., “A computational fluid dynamics modeling of natural convection in finned enclosure under electric field, Applied Thermal Engineering, Vol. 29, pp.131-141., 2009.
【22】Kasayapanand, N., “Electrohydrodynamic enhancement of heat transfer in vertical fin array using computational fluid dynamics technique, International Communications in Heat and Mass Transfer, Vol. 35, pp. 762-770., 2008.
【23】Hashinaga, F., Bajgai, T.R., Isobe, S. and Barthakur, N.N., “Electrohydrodynamic(EHD) Drying of Apple Slices, Drying Technology, Vol. 17, No. 3, pp. 479-495., 1999.
【24】Leu, J.S., Jang, J.Y. and Wu, Y.H., “Optimization of the Wire Electrode Height and Pitch for 3-D Electrohydrodynamic Enhanced Water Evaporation, International Journal of Heat and Mass Transfer, Vol. 118, pp. 976-988., 2018.
【25】Lai, F.C. and Sharma, R.K., “EHD-Enhanced Drying with Multiple Needle Electrode, Journal of Electrostatics, Vol. 63, pp. 223-237., 2005.
【26】Kulacki, F.A., and Daumenmier, J.A., “A Preliminary Study of Electrohydrodynamic Augumented Baking, Journal of Electrostatics, Vol. 5, pp. 325-336., 1978.
【27】Wang, J., Cai, Y.X., Bao, W.W., Li, H.X. and Liu, Q., “Experimental study of high power LEDs heat dissipation based on corona discharge, Applied Thermal Engineering, Vol. 98, pp. 420-429., 2016.
【28】Zhang, Y., Liu, L., Yang, C. and Ouyang, J., “Characteristics of ion wind in needle-to-ring corona discharge, Journal of Electrostatics, Vol. 74, pp. 15-20., 2015.
【29】Chen, Y.C., Guo, M.Z., Yang, K.S. and Wang, C.C., “Enhanced cooling for LED lighting using ionic wind, International Journal of Heat and Mass Transfer, Vol. 57, pp. 285-291., 2013.
【30】Launder, B.E., and Spalding, D.B., “The Numerical Computation of Turbulent Flows,Computer methods in applied mechanics and engineering,Vol. 3, pp. 269-287., 1974.
【31】Fletcher, R., and Reeves, C. M., “Function Minimization by Conjugate Gradients, Computer Journal,7,pp.149-154., 1964.
【32】Cheng, C, H., and Chang, M. H., “A simplified Conjugate-Gradient Method for Shape Identification Based on Thermal Data, Numerical Heat Transfer,Part B, 43,pp.489-507., 2003.
【33】Van Doormaal, J. P. and Raithby, G. D. “Enhancements of the SIMPLE method for predicting incompressible fluid flows, Numerical Heat Transfer, Vol.7, pp.147-163., 1984.
【34】Peek, F.w., “Determination Phenomena in High Voltage Engineering, McGraw-Hill, New York, 52-80.,1929
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