CONCEPTUALIZATION, THERMAL ANALYSIS, AND MANUFACTURING OF NANO-TEXTURED MICRO-STRUCTURED SURFACES FOR ENHANCED CONDENSATION HEAT TRANSFER

Year 2021, , 867 - 889, 01.05.2021

Mete Budaklı

https://doi.org/10.18186/thermal.930682

Abstract

In the present study, nano-micro-structured surfaces have been systematically designed and manufactured in order to generate controlled dropwise condensation mode for enhanced heat transfer during phase-change from vapor to liquid. The conceptualization of micro-structures was conducted by using thermal modelling of an individ-ual droplet pinned at a single micro-hexagonal cavity. By varying droplet radius, resulting contact angles and geo-metric dimensions of micro-structure, threshold values have been determined for the later manufacturing process. According to the calculations for instance at contact angles of 150°, a subcooling of 1 K and a maximum droplet radius of 100 µm, the edge length and the depth of the micro-structures should be kept below 50 µm and 25 µm, respectively. Ensuring these parameters, a roughly 100 % larger heat transfer coefficient would result compared to that predicted by the classical Nusselt theory for filmwise condensation. Taking into account the mathematical analysis, laser ablation technique was adopted on 7075 aluminum samples to emboss hexagonal structures with respect to the predicted dimensions. After this step, the samples were electrochemically etched in order to achieve contact angles of more than 150° to ensure superhydrophobic solid-liquid interaction at the surface. Measurements with a high-precision microscope show that most of the structure dimensions and geometric shape were precisely manufactured. The Tensiometer results disclosed that the surface topography at all samples exhibit contact angles larger than 150° for a sessile droplet with a radius of 100 µm pinned on an individual micro-hexagon.

Keywords

Micro-structured Surfaces, Dropwise Condensation, Heat Transfer, Thermal Modelling

References

• [1] Giradkar PD, Wankhede US. High Heat Flux Micro-Electronics Cooling. International Journal of Modern Engineering Research 2013;3:336–41.
• [2] Launay S, Sartre V, Bonjour J. Parametric analysis of loop heat pipe operation: a literature review. International Journal of Thermal Sciences 2007;46:621–36. https://doi.org/10.1016/j.ijthermalsci.2006.11.007.
• [3] Ma X, Chen J, Li S, Sha Q, Liang A, Li W, et al. Application of absorption heat transformer to recover waste heat from a synthetic rubber plant. Applied Thermal Engineering 2003;23:797–806. https://doi.org/https://doi.org/10.1016/S1359-4311(03)00011-5.
• [4] Jo H, Yu DI, Noh H, Park HS, Kim MH. Boiling on spatially controlled heterogeneous surfaces: Wettability patterns on microstructures. Applied Physics Letters 2015;106:181602. https://doi.org/10.1063/1.4919916.
• [5] Zhong Y, Jacobi AM, Georgiadis JG. Condensation and Wetting Behavior on Surfaces With Micro-Structures : Super-Hydrophobic and Super-Hydrophilic. International Refrigeration and Air Conditioning Conference at Purdue University 2006:R100, 1–8.
• [6] Hu S, Ma X, Zhou W. Condensation heat transfer of ethanol-water vapor in a plate heat exchanger. Applied Thermal Engineering 2017;113:1047–55. https://doi.org/10.1016/j.applthermaleng.2016.11.013.
• [7] Beér JM. High efficiency electric power generation: The environmental role. Progress in Energy and Combustion Science 2007;33:107–34. https://doi.org/https://doi.org/10.1016/j.pecs.2006.08.002.
• [8] Liu Y, Kulacki FA. An experimental study of defrost on treated surfaces: Effect of frost slumping. International Journal of Heat and Mass Transfer 2018;119:880–90. https://doi.org/10.1016/j.ijheatmasstransfer.2017.12.018.
• [9] Miljkovic N. Development and Characterization of Micro / Nano structured Surfaces for Enhanced Condensation. Massachusetts Institute of Technology, 2013.
• [10] Mu C, Pang J, Lu Q, Liu T. Effects of surface topography of material on nucleation site density of dropwise condensation. Chemical Engineering Science 2008;63:874–80. https://doi.org/10.1016/j.ces.2007.10.016.
• [11] Rausch MH, Fröba AP, Leipertz A. Dropwise condensation heat transfer on ion implanted aluminum surfaces. International Journal of Heat and Mass Transfer 2008;51:1061–70. https://doi.org/10.1016/j.ijheatmasstransfer.2006.05.047.
• [12] Yan J, Yang Y, Hu S, Zhen K, Liu J. Effects of vapor pressure/velocity and concentration on condensation heat transfer for steam-ethanol vapor mixture. Heat and Mass Transfer/Waerme- Und Stoffuebertragung 2007;44:51–60. https://doi.org/10.1007/s00231-006-0216-5.
• [13] Tanner DW, Pope D, Potter CJ, West D. Heat transfer in dropwise condensation at low steam pressures in the absence and presence of non-condensable gas. International Journal of Heat and Mass Transfer 1968;11:181–90. https://doi.org/10.1016/0017-9310(68)90148-8.
• [14] Roudgar M, De Coninck J. Condensation heat transfer coefficient versus wettability. Applied Surface Science 2015;338:15–21. https://doi.org/10.1016/j.apsusc.2015.02.087.
• [15] Wilkins DG, Bromley LA, Read SM. Dropwise and filmwise condensation of water vapor on gold. AIChE Journal 1973;19:119–23. https://doi.org/10.1002/aic.690190117.
• [16] Chatterjee A, Derby MM, Peles Y, Jensen MK. Condensation heat transfer on patterned surfaces. International Journal of Heat and Mass Transfer 2013;66:889–97. https://doi.org/10.1016/j.ijheatmasstransfer.2013.07.077.
• [17] Zaitsev DV, Batishcheva KA, Kuznetsov GV, Orlova EG. Prediction of water droplet behavior on aluminum alloy surfaces modified by nanosecond laser pulses. Surface and Coatings Technology 2020;399:126206. https://doi.org/10.1016/j.surfcoat.2020.126206.
• [18] Zhao Q, Burnside BM. DROPWISE CONDENSATION OF STEAM ON ION IMPLANTED CONDENSER SURFACES. Heat Recovery Systems and CHP 1994;14:525–34.
• [19] Zarei S, Talesh Bahrami HR, Saffari H. Effects of geometry and dimension of micro/nano-structures on the heat transfer in dropwise condensation: A theoretical study. Applied Thermal Engineering 2018;137:440–50. https://doi.org/10.1016/j.applthermaleng.2018.04.003.
• [20] Yang K-S, Lu W, Wu Y-L. Visualization of Patterned Modified Surfaces in Condensation and Frosting States. Energies 2019;12:4471. https://doi.org/10.3390/en12234471.
• [21] Liu M, Li J, Zhou X, Li J, Feng S, Cheng Y, et al. Inhibiting Random Droplet Motion on Hot Surfaces by Engineering Symmetry‐Breaking Janus‐Mushroom Structure. Advanced Materials 2020;32:1907999. https://doi.org/10.1002/adma.201907999.
• [22] Orejon D, Shardt O, Gunda NSK, Ikuta T, Takahashi K, Takata Y, et al. Simultaneous dropwise and filmwise condensation on hydrophilic microstructured surfaces. International Journal of Heat and Mass Transfer 2017;114:187–97. https://doi.org/10.1016/j.ijheatmasstransfer.2017.06.023.
• [23] Schmidt E, Schurig W, Sellschopp W. Versuche über die Kondensation von Wasserdampf in Film- und Tropfenform. Technische Mechanik Und Thermodynamik 1930;1:53–63. https://doi.org/10.1007/BF02641051.
• [24] Baojin Q, Li Z, Hong X, Yan S. Experimental study on condensation heat transfer of steam on vertical titanium plates with different surface energies. Experimental Thermal and Fluid Science 2011;35:211–8. https://doi.org/10.1016/j.expthermflusci.2010.09.003.
• [25] Acatay K, Simsek E, Ow-Yang C, Menceloglu YZ. Tunable, superhydrophobically stable polymeric surfaces by electrospinning. Angewandte Chemie - International Edition 2004;43:5210–3. https://doi.org/10.1002/anie.200461092.
• [26] Koch C, Kraft K, Leipertz A. Parameter Study on the Performance of Dropwise Condensation. International Journal of Thermal Sciences 1998;37:539–48.
• [27] Worthington AM. A second paper on the forms assumed by drops of liquids falling vertically on a horizontal plate. Proc. R. Soc. London, 25, 1876, p. 498–503.
• [28] Furuta T, Nakajima A, Sakai M, Isobe T, Kameshima Y, Okada K. Evaporation and sliding of water droplets on fluoroalkylsilane coatings with nanoscale roughness. Langmuir 2009;25:5417–20. https://doi.org/10.1021/la8040665.
• [29] Hong BS, Han JH, Kim ST, Cho YJ, Park MS, Dolukhanyan T, et al. Endurable water-repellent glass for automobiles. Thin Solid Films 1999;351:274–8. https://doi.org/10.1016/S0040-6090(98)01794-5.
• [30] Yuvaraj R, Senthkil K. Study of droplet dynamics and condensation heat transfer on superhydrophobic copper surface. Thermal Science 2021;25:653–64. https://doi.org/10.2298/TSCI190126089Y.
• [31] Kobayashi H, Owen MJ. Surface Tension of Poly[(3,3,4,4,5,5,6,6,6-nonafluorohexyl)-methylsiloxane]. Macromolecules 1990;23:4929–33. https://doi.org/10.1021/ma00225a008.
• [32] Betz AR, Jenkins J, Kim CJ, Attinger D. Boiling heat transfer on superhydrophilic, superhydrophobic, and superbiphilic surfaces. International Journal of Heat and Mass Transfer 2013;57:733–41. https://doi.org/10.1016/j.ijheatmasstransfer.2012.10.080.
• [33] Sharma CS, Stamatopoulos C, Suter R, von Rohr PR, Poulikakos D. Rationally 3D-Textured Copper Surfaces for Laplace Pressure Imbalance-Induced Enhancement in Dropwise Condensation. ACS Applied Materials & Interfaces 2018;10:29127–35. https://doi.org/10.1021/acsami.8b09067.
• [34] Balekjian G, Katz DL. Heat transfer from superheated vapors to a horizontal tube. AIChE Journal 1958;4:43–8. https://doi.org/10.1002/aic.690040109.
• [35] Webb RL. Convective condensation of superheated vapor. Journal of Heat Transfer 1998;120:418–21. https://doi.org/10.1115/1.2824266.
• [36] Chen K, Sun T. Effects of microstructure design on aluminum surface hydrophobic and ice-retarding properties. Asia-Pacific Journal of Chemical Engineering 2017;12:307–12. https://doi.org/10.1002/apj.2073.
• [37] Cengel Y, Ghajar A. Heat and mass transfer. Heat and Mass Transfer: Fundamentals and Applications. Fifth Ed., The McGraw-Hill Companies; 2015.
• [38] Nusselt W. Die Oberflächenkondensation des Wasserdampfes. Zeitschrift Des Vereins Deutscher Ingenieure 1916;60:541–546.
• [39] McCormick JL, Baer E. On the mechanism of heat transfer in dropwise condensation. Journal of Colloid Science 1963;18:208–16. https://doi.org/10.1016/0095-8522(63)90012-6.
• [40] Sikarwar BS, Khandekar S, Agrawal S, Kumar S, Muralidhar K. Dropwise condensation studies on multiple scales. Heat Transfer Engineering 2012;33:301–41. https://doi.org/10.1080/01457632.2012.611463.
• [41] Paxson AT, Yagüe JL, Gleason KK, Varanasi KK. Stable dropwise condensation for enhancing heat transfer via the initiated chemical vapor deposition (iCVD) of grafted polymer films. Advanced Materials 2014;26:418–23. https://doi.org/10.1002/adma.201303065.
• [42] Bi P, Li H, Zhao G, Ran M, Cao L, Guo H, et al. Robust super-hydrophobic coating prepared by electrochemical surface engineering for corrosion protection. Coatings 2019;9. https://doi.org/10.3390/coatings9070452.
• [43] Wen R, Lan Z, Peng B, Xu W, Ma X. Droplet dynamics and heat transfer for dropwise condensation at lower and ultra-lower pressure. Applied Thermal Engineering 2015;88:265–73. https://doi.org/10.1016/j.applthermaleng.2014.09.069.
• [44] Yamada Y, Takahashi K, Ikuta T, Nishiyama T, Takata Y, Ma W, et al. Tuning Surface Wettability at the Submicron-Scale: Effect of Focused Ion Beam Irradiation on a Self-Assembled Monolayer. Journal of Physical Chemistry C 2016;120:274–80. https://doi.org/10.1021/acs.jpcc.5b09019.
• [45] Andrieu C, Beysens DA, Nikolayev VS, Pomeau Y. Coalescence of sessile drops. Journal of Fluid Mechanics 2002;453:427–38. https://doi.org/DOI: 10.1017/S0022112001007121.
• [46] Marto PJ, Looney DJ, Rose JW, Wanniarachchi AS. Evaluation of organic coatings for the promotion of dropwise condensation of steam. International Journal of Heat and Mass Transfer 1986;29:1109–17. https://doi.org/https://doi.org/10.1016/0017-9310(86)90142-0.
• [47] Koch G, Zhang DC, Leipertz A. Condensation of steam on the surface of hard coated copper discs. Heat and Mass Transfer 1997;32:149–56. https://doi.org/10.1007/s002310050105.
• [48] Budakli M, Salem TK, Arik M, Donmez B, Menceloglu Y. Effect of Polymer Coating on Vapor Condensation Heat Transfer. Journal of Heat Transfer 2020;142. https://doi.org/10.1115/1.4046300.
• [49] Budakli M, Salem TK, Arik M, Dönmez B, Menceloglu Y. An experimental study on the heat transfer and wettability characteristics of micro-structured surfaces during water vapor condensation under different pressure conditions. International Communications in Heat and Mass Transfer 2021;120:105063. https://doi.org/10.1016/j.icheatmasstransfer.2020.105063.
• [50] Carey VP. Liquid-Vapor Phase-Change Phenomena: An Introduction to the Thermophysics of Vaporization and Condensation Processes in Heat Transfer Equipment. New York: Taylor and Francis; 2008. https://doi.org/https://lib.ugent.be/catalog/rug01:001430011.
• [51] Schrage RW. A Theoretical Study of Interphase Mass Transfer. New York: Columbia University Press; 1953.
• [52] Umur A, Griffith P. Mechanism of Dropwise Condensation. Journal of Heat Transfer 1965;87:275–82. https://doi.org/10.1115/1.3689090.
• [53] Rohsenow WM. Status of and Problems in Boiling and Condensation Heat Transfer. Pergamon Press; 1972. https://doi.org/10.1016/b978-0-08-017035-0.50007-0.
• [54] Miljkovic N, Enright R, Wang EN. Modeling and optimization of superhydrophobic condensation. Journal of Heat Transfer 2013;135. https://doi.org/10.1115/1.4024597.
• [55] Cha H, Vahabi H, Wu A, Chavan S, Kim MK, Sett S, et al. Dropwise condensation on solid hydrophilic surfaces. Science Advances 2020;6. https://doi.org/10.1126/sciadv.aax0746.