The authors gratefully acknowledge funding support from the Ministry of Science and Technology, MOST (project numbers: MOST 104-2218-E-002 -004, MOST 105-2218-E-002-019, MOST 105-2221-E-002 -107 -MY3, MOST 102-2221-E-002 -133 -MY3, and MOST 102-2221-E-002 -088 -MY3).

Modifiye Yüzeylerin hazırlanması 1. <ol><li> El ile bir # 2000 zımpara kullanılarak 15 dakika boyunca test parçası (içi boş bakır silindir 40 mm uzunlukta (I), 25 mm dış çap (d o), ve bir 18 mm iç çapa (D)) cila kağıt. DI su takiben aseton ile durulayarak cilalı yüzeyi temizleyin. </li><li> 120 ° C&#39;lik sabit bir sıcaklıkta, 2 saat için bir fırın içinde cilalı test parçası yerleştirin. </li><li> Aşağıdaki aşamaları kullanarak bir süperhidrofilik SİO2 nanopartikül çözeltisi hazırlayın. <ol><li> tetraetoksi silan ve Dİ suyu 4 mol oranları: 1 karıştırılarak çözelti A hazırlayın. % 37 2 damla solüsyon A&#39;ya konsantre HCI ve 2 saat süreyle karışmaya ekleyin. </li><li> etanol ve deiyonize suda 3 molar oranı: 1 karıştırılarak çözelti B olun. </li><li> Çözelti B, 80 mL çözelti A 1 mL karıştırın ve 2 saat boyunca karıştırın. </li><li> Hazırlanan Solu SİO2 nanopartiküller (40 nm çapında) 32 g ekleme1 saat boyunca tion ve karıştırma. </li></ol></li><li> 5 mm / dk&#39;lık bir hızda daldırma kaplama düzeneği kullanılarak hazırlanan çözelti içinde test parçası bırakın. 1 saat boyunca 120 ° C de bir fırında kaplanmış test parçası tutun. </li><li> Aşağıdaki adımları kullanarak (Şekil 1 &#39;de gösterildiği gibi), eksenel yönde, farklı yönelimler, 2, 4 ve 8 interlined hibrid desen hazırlayın. <ol><li> merkezi ve PE kaplama alanı kaplanacak (bölge) üzerine en INTERLINES ayarlamak alanı Maske 0 ° &#39;lik yönelimde 2-interline yüzey için doğru bir yönelimde ile (fugalara gerekli sayıda uygun yalıtım bandı kullanarak kaplanmamış olması üst kısım. diğer yandan, 90 ° yönlendirme için, alt ve üst bir de bir satırlar arası ayarlayın ve 180 ° yönlendirme için, PE kaplama altındaki alan ve merkezde INTERLINES ayarlayın. Benzer şekilde, ayarlamak farklı o ile 4, 8 interlined yüzeylerin pozisyonrientation olarak, Şekil 1 &#39;de gösterilmektedir). </li><li> 5 mm / dakika yavaş hızda, yüksek daldırma hız ve artış bir daldırma kaplama aparatı, daldırma kullanılarak hazırlanan çözelti içinde maskeli test parçası bırakın. 1 saat boyunca 120 ° C de bir fırında kaplanmış test parçası tutun. </li><li> Uygun bir yönlendirme ile fugalara gerekli sayıda elde etmek için maskelenmiş alandan bandı çıkarın. </li></ol></li></ol><img alt="Şekil 1" src="/files/ftp_upload/55387/55387fig1.jpg" /> Şekil 1. Çeşitli Interlined Yüzeylerin seçilmesi. değişik konumları bulunan çeşitli interlined yüzeyler (a) şematik. Tüm koşullar, 1: düz bir bakır yüzeyi ve bir PE kaplama yüzeyinin alanı oranı 1&#39;dir. (b) Yönlendirme seçim kriterleri. (c) 2 interline 0 ° açı bakan yüzeyi izometrik görünüşüdür. Yönlendirme taban ve kaplama arasındaki açı olarak seçilir:Merkezi üst taraftan birinci hidrofilik Desenin hattı ve bir saat yönünde ölçülür. <a href="http://ecsource.jove.com/files/ftp_upload/55387/55387fig1large.jpg" target="_blank">Bu rakamın büyük halini görmek için buraya tıklayın.</a> 2. Deneysel Prosedür <ol><li> izolasyon bandı kullanılarak kaplanmış test parçasının her bir dairesel taban az bir cam tüp düzeltin. </li><li> Fugalara gerekli konumuna göre, silikon macunu kullanılarak (Şekil 2&#39;de gösterildiği gibi) yatay 140- x 140- x 160 mm bölmesine bu montaj grubunu sabitleme. </li><li> 550 W, 18 mm&#39;lik bir çapa ve test parçasının deliğe çevresel alanı üzerinde termal macun, ince bir film ile, 40 mm uzunluğundaki kartuş ısıtıcısını yerleştirin. </li><li> Bir doğru akım (DC) güç kaynağı ünitesine kartuş ısıtıcı bağlayın. </li><li> Şekilde gösterildiği gibi, 5 mm, 7 mm alternatif derinliğine sahip 8 eşit aralıklı 1 mm delikler içine yerleştirin T türü termokupl3 veri kaydedici onları bağlayın. </li><li> Üst kapak üzerinde temin mekanlarda (RTD), bir geri akış kondansatörü ve bir yardımcı ısıtıcı yerleştirin ve direnç sıcaklık dedektörü düzeltin. Kaynar odasının üzerine bunları düzelt. </li><li> havuz kaynama odası içine Dİ suyu 1.400 mL doldurun. </li><li> 5 ° C &#39;de muhafaza edilen bir soğutma bölmesine geri akış kondansatörü bağlayın. </li><li> Önceki deneyden, kuvvetli bir şekilde yardımcı ısıtıcı kullanılarak 30 dakika boyunca havuz kaynama odası içinde distile su kaynatın. </li><li> Yardımcı ısıtıcı kullanarak, doymuş, kaynama koşullarında distile su tutun. Daha sonra, güç kaynağı geçiş ve 0.1 A bir ilk akım vermek </li><li> kararlı bir duruma ulaşması için 2 dakika bekleyin. Daha sonra, 0.3 A artışlarla elektrik akımını artırmak </li><li> veri kaydedici kullanarak her bir güç girişindeki sıcaklık kaydedilir. 4 A maksimum akım ulaşılana kadar deney devam edin. Bu arada, kabarcık dinamiği f kayıt<html> ya da bir CCD kamera ile her bir güç girişi test parçası üzerinde odaklanmıştır havuz kaynama odası, önüne yerleştirilir. </li></ol><img alt="şekil 2" src="/files/ftp_upload/55387/55387fig2.jpg" /> Havuz kaynatma Odası Şekil 2. Şematik. Cam tüpler, silikon macun ile, içi boş, bakır silindirin her iki tarafına bağlanır. Bu silikon macun ile havuz kaynar odasına sabittir. <a href="http://ecsource.jove.com/files/ftp_upload/55387/55387fig2large.jpg" target="_blank">Bu rakamın büyük halini görmek için buraya tıklayın.</a> <img alt="Şekil 3," src="/files/ftp_upload/55387/55387fig3.jpg" /> 3. Termokupl Konumlandırma Şekil. 8 termokupl 20 mm&#39;lik bir çap test parçası yerinde çevresel 1 mm çaplı delikli içine yerleştirilir. Alternatif 1 mm çapında delikleri derinlikleri 5 mm ve sırasıyla 7 mm sabitlenir./files/ftp_upload/55387/55387fig3large.jpg&quot; target = &#39;_ blank&#39;&gt; bu rakamın büyük halini görmek için lütfen buraya tıklayın. 3. Veri İndirgeme <ol><li> Aşağıdaki denklem 19 kullanılarak ısı girişi (S) hesaplayın S = I-V (1) Not: I ve V sırasıyla amper giriş akımı ve volt gerilim vardır. </li><li> Formül 19 ile iki yan yüzeylerden ısı kaybının (S kaybı) tahmin edilmesi: <img alt="Denklem 2" src="/files/ftp_upload/55387/55387eq2.jpg" /> (2) Not: k bakırın ısıl iletkenliği; T 7 mm ve T, 5 mm, 7 mm ve sırasıyla 5 mm derinliğe kadar sıcaklığın ortalama değerlerdir; Ax (2 mm) derinlikleri arasındaki farktır; ve <img alt="Denklem 2B" src="/files/ftp_upload/55387/55387eq2b.jpg" /> Test p enine kesit alanıdır<html> IECE. </li><li> Aşağıdaki formül 19 kullanılarak (q &#39;), ısı akışının belirlenmesi: <img alt="Denklem 3" src="/files/ftp_upload/55387/55387eq3.jpg" /> (3) Not: A = π d t l, test parçasının çevresel bir alandır. </li><li> Aşağıdaki denklem 19 kullanarak duvar süper ısısını (hesaplayın: <img alt="Denklem 4" src="/files/ftp_upload/55387/55387eq4.jpg" /> (4) Not: Tm T 7 mm ve T, 5 mm ortalama, test parçası, RO (12,5 mm) test parçasının dış yarıçapı r m (10 mm) test parçasının yarıçapı uzunluğudur Şekil 4&#39;te gösterildiği gibi, delik ölçme ve T doymuş DI su doyma sıcaklığıdır. </li><li> Aşağıdaki formül 19 kullanılarak HTC (α) hesaplayın: celle / 55387 / 55387eq5.jpg&quot;/&gt; (5) </li></ol><img alt="Şekil 4," src="/files/ftp_upload/55387/55387fig4.jpg" /> Duvar Sıcaklık Analiz Şekil 4. şematik. Duvar sıcaklığı ölçülen ortalama sıcaklığını ve bilinen silindirik ısı direnci kullanılarak hesaplanır. <a href="http://ecsource.jove.com/files/ftp_upload/55387/55387fig4large.jpg" target="_blank">Bu rakamın büyük halini görmek için buraya tıklayın.</a>

<ol>
	<li>Putsch, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+challenges+in+the+next+generation+of+supercomputers.">Thermal challenges in the next generation of supercomputers.</a> Proc. CoolCon MEECC Conference. , 1-83 (2005).</li><li>Phan, H. T., Caney, N., Marty, P., Colasson, S., Gavillet, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+wettability+control+by+nanocoating:+The+effect+on+pool+boiling+heat+transfer+and+nucleation+mechanism.">Surface wettability control by nanocoating: The effect on pool boiling heat transfer and nucleation mechanism.</a> Int. J. Heat and Mass Transfer. 52, 5459-5471 (2009).</li><li>Barber, J., Brutin, D., Tadrist, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+on+boiling+heat+transfer+enhancement+with+nanofluids.">A review on boiling heat transfer enhancement with nanofluids.</a> Nanoscale Res. Lett. 6 (1), 280 (2011).</li><li>Kim, S. J., Bang, I. C., Buongiorno, J., Hu, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+nanoparticle+deposition+on+surface+wettability+influencing+boiling+heat+transfer+in+nanofluids.">Effects of nanoparticle deposition on surface wettability influencing boiling heat transfer in nanofluids.</a> Appl. Phys. Lett. 89, 153107 (2006).</li><li>Berenson, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiments+on+pool-boiling+heat+transfer.">Experiments on pool-boiling heat transfer.</a> Int. J. Heat Mass Transfer. 5 (10), 985-999 (1962).</li><li>You, S. M., Simon, T. W., Bar-Cohen, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+technique+for+enhancing+boiling+heat+transfer+with+application+to+cooling+of+electronic+equipment.">A technique for enhancing boiling heat transfer with application to cooling of electronic equipment.</a> IEEE Trans. Compon. Hybrids Manuf. Tech. 15 (5), 823-831 (1992).</li><li>Li, C., Peterson, G. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parametric+study+of+pool+boiling+on+horizontal+highly+conductive+microporous+coated+surfaces.">Parametric study of pool boiling on horizontal highly conductive microporous coated surfaces.</a> J. Heat Transfer. 129 (11), 1465-1475 (2007).</li><li>Trisaksri, V., Wongwises, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Critical+review+of+heat+transfer+characteristics+of+nanofluids.">Critical review of heat transfer characteristics of nanofluids.</a> Renew. Sust. Energy Rev. 11 (3), 512-523 (2007).</li><li>Trisaksri, V., Wongwises, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleate+Pool+Boiling+Heat+Transfer+of+TiO2-R141b+nanofluids.">Nucleate Pool Boiling Heat Transfer of TiO2-R141b nanofluids.</a> Int. J. Heat Mass Transfer. 52 (5-6), 1582-1588 (2009).</li><li>Suriyawong, A., Wongwises, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleate+pool+boiling+heat+transfer+characteristics+of+TiO2-+water+nanofluids+at+very+low+concentrations.">Nucleate pool boiling heat transfer characteristics of TiO2- water nanofluids at very low concentrations.</a> Exp. Therm. Fluid Sci. 34 (8), 992-999 (2010).</li><li>Suriyawong, A., Dalkilic, A. S., Wongwises, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleate+Pool+Boiling+Heat+Transfer+Correlation+for+TiO2-Water+Nanofluids.">Nucleate Pool Boiling Heat Transfer Correlation for TiO2-Water Nanofluids.</a> J. ASTM Int. 9 (5), 1-12 (2012).</li><li>Sarangi, S., Weibel, J. A., Garimella, S. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+particle+size+on+surface-coating+enhancement+of+pool+boiling+heat+transfer.">Effect of particle size on surface-coating enhancement of pool boiling heat transfer.</a> Int. J. Heat Mass Transfer. 81, 103-113 (2015).</li><li>Kumar, C. S. S., Suresh, S., Kumar, M. C. S., Gopi, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+surfactant+addition+on+hydrophilicity+of+ZnO-Al2O3+composite+and+enhancement+of+flow+boiling+heat+transfer.">Effect of surfactant addition on hydrophilicity of ZnO-Al2O3 composite and enhancement of flow boiling heat transfer.</a> Exp. Therm. Fluid Sci. 70, 325-334 (2016).</li><li>Takata, Y., Hidaka, S., Uraguchi, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Boiling+feature+on+a+super+water-repellent+surface.">Boiling feature on a super water-repellent surface.</a> Heat Transfer Eng. 27 (8), 25-30 (2006).</li><li>Takata, Y., Hidaka, S., Masuda, M., Ito, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pool+boiling+on+a+super+hydrophilic+surface.">Pool boiling on a super hydrophilic surface.</a> Int. J. Energy Res. 27 (2), 111-119 (2003).</li><li>Takata, Y., Hidaka, S., Kohno, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+nucleate+boiling+by+super+hydrophobic+coating+with+checkered+and+spotted+patterns.">Enhanced nucleate boiling by super hydrophobic coating with checkered and spotted patterns.</a> International Conference on Boiling Heat Transfer. , (2006).</li><li>Hsu, C. C., Chiu, W. C., Kuo, L. S., Chen, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversed+boiling+curve+phenomenon+on+surfaces+with+interlaced+wettability.">Reversed boiling curve phenomenon on surfaces with interlaced wettability.</a> AIP Advances. 4, 107110 (2014).</li><li>Jo, H., Ahn, H. S., Kang, S. H., Kim, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+study+of+nucleate+boiling+heat+transfer+on+hydrophilic,+hydrophobic+and+heterogeneous+wetting+surface.">A study of nucleate boiling heat transfer on hydrophilic, hydrophobic and heterogeneous wetting surface.</a> Int. J. Heat Mass Transfer. 54 (25-26), 5643-5652 (2011).</li><li>Mehta, J. S., Kandlikar, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pool+boiling+heat+transfer+enhancement+over+cylindrical+tubes+with+water+at+atmospheric+pressure,+Part+I:+Experimental+results+for+circumferential+rectangular+open+microchannels.">Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results for circumferential rectangular open microchannels.</a> Int. J. Heat Mass Transfer. 64, 1205-1215 (2013).</li><li>Cornwell, K., Houston, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleate+Pool+Boiling+on+Horizontal+Tubes+-+a+Convection-Based+Correlation.">Nucleate Pool Boiling on Horizontal Tubes - a Convection-Based Correlation.</a> Int. J. Heat Mass Transfer. 37, 303-309 (1994).</li><li>Holman, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Experimental Methods for Engineers. , (2007).</li></ol>

The authors declare that they have no competing financial interests.

The main goal of this investigation was to develop a pool-boiling heat sink for high heat dissipation applications, such as nuclear reactors, boilers, and heat pipes, by introducing the hybrid wettable surface, as described in the protocol section. These surfaces can produce better pool-boiling performances than homogeneous wettable surfaces (hydrophilic and hydrophobic). The improvement in the boiling heat-transfer performance is due to an increase in active nucleation sites and the easy detachment of the formed bubbles...

10-10 Mayıs W aralığında soğutma sağlayan bir yüksek ısı akışı besleyen sistemi / cm2 elektronik, savunma, aviyonik ve nükleer cihaz gelişme ortaya çıkan alanlar gereklidir. hava ile geleneksel bir soğutma nedeniyle serbest ve baskılı-konveksiyon koşullar için düşük ısı transferi katsayısı (HTC) için, bu uygulamalar için yeterli değildir. 1,000 W / cm 2 1 - bu ve havuz kaynama gibi faz değişimine dayalı bir soğutma teknikleri, kaynar, akış 10 mertebesinde yüksek ısı akısı kaldırmak için yeterince iyi. iki fazlı bir ısı aktarma işlemi izotermal olduğu için, soğutulmuş, cihaz sıcaklığının yüzey boyunca hemen hemen sabittir. Nedeniyle yüzeyi boyunca sıcaklığın önemsiz değişiklikler nedeniyle, cihazın termal şok elimine edilebilir. Bununla birlikte, ısı transferi kaynayan temel sınırlayıcı parametre sıcaklığında 2 anormal artışa neden olur ve kritik ısı akısı (KKY) &#39;dir </sup&gt;. Son birkaç on yılda, kapsamlı araştırma yüzey modifikasyonu, nanosıvıları ve yüzey kaplamaları, 3, 4, 5, 6, 7, 8, 9, 10, 11 kullanarak CHF geliştirmek için yürütülmüştür. Çeşitli yöntemler arasında, yüzey kaplamaları, yüzey alanında önemli bir artış CHF geliştirmek için en iyi yöntem olduğu bulunmuştur. Yüzey kaplamaları genellikle kanatçık eylem, gözeneklilik etkileri ve yüzey ıslanabilirlik 12 ısı transferini artırır. Yüzey ıslanabilirlik ısı transferi kaynayan önemli bir rol oynamaktadır. Daha önceki çalışmalar, düşük ısı akışı koşullarında, hidrofobik yüzey nedeniyle erken nükleasyon daha HTC göstermektedir göstermektedir. Ancak, endaha yüksek ısı akışı, oluşan kabarcıkların ayrılması nedeniyle yüzeyine doğru suyun düşük afinite yavaştır. Bu balon birleşmesine yol açar ve bir alt CHF 3 ile sonuçlanır. Öte yandan, bir hidrofilik yüzey nedeniyle oluşan kabarcıkların hızlı dekolmanı, daha yüksek bir CHF üretir, fakat bu durum hava kabarcığı 13 gecikme nedeniyle, düşük ısı akısı daha düşük bir HTC verir. Hibrid yapıları nedeniyle hidrofobiklik ve hidrofiliklik 14, 15, 16 kombine etkisine tüm ısı kaplama için ısı transferini kaynayan dikkate değer bir artışı göstermektedir. Hsu ve ark. PE kaplama Si kaplamak suretiyle üretilen heterojen ıslatılabilir bir yüzey maskeli bakır yüzeyi üzerinde nano-tanecikleriyle. Bunlar kaplama süresi değiştirilerek farklı ıslanabilirlik oranlarını sağladı. kaynama başlangıcı saat göre heterojen yüzeylerde daha önce meydana gelenesas itibariyle bir duvar düşük omogeneous yüzey 17, aşırı ısıtma. Jo ve diğ. Hidrofilik, hidrofobik, ve heterojen ıslatma yüzeylerinde çekirdek kaynama ısı transferi çalışmalarını gerçekleştirdik. Heterojen ıslatma yüzeyi hidrofilik yüzeye hidrofobik desenli noktalar oluşmuştur. Daha yüksek HTCs ve hidrofilik yüzey ile karşılaştırıldığında, heterojen yüzeyi aynı CHF var. Isı transferini kaynayan bir gelişme, doğrudan yüzeye ve kaynama koşulları 18 üzerine noktalar sayısına bağlıdır. Bu çalışmada, eksenel hibrid ıslatılabilir desenler daldırma kaplama tekniği kullanılarak silindirik bakır yüzeyi üzerinde üretilmiştir. Havuz kaynama noktalı bir ısı-transfer çalışmaları fugalara sayısı ve hibrid ıslatılabilir modelinin yönüne etkilerini belirlemek için deneyler yapılmıştır. Kaynama ısı akısı, HTC ve balon dinamikleri Tüm kaplanmış alt tabakalar ve biz için analiz edildiBakır alt-tabaka ile karşılaştırıldığında, yeniden.

<table><tbody><tr><td>Deionized water</td><td></td><td></td><td></td></tr><tr><td>Silica nanopowder,40 nm</td><td>UniRegion Bio-Tech</td><td>60676860</td><td></td></tr><tr><td>Ethanol</td><td>ECHO Chemical co. Ltd</td><td>64175</td><td></td></tr><tr><td>Hydrochloric acid</td><td>SHOWA Chemical co. Ltd.</td><td>7647010</td><td></td></tr><tr><td>Tetraethoxysilane</td><td>SHOWA Chemical co. Ltd.</td><td>78104</td><td></td></tr><tr><td>Acetone</td><td>UNI-ONWARD CORP.</td><td>67641</td><td></td></tr><tr><td>Cartridge Heater</td><td>Chung Shun Heater &amp;amp; Instrument Co, Ltd.</td><td></td><td></td></tr><tr><td>Pyrex glass&amp;nbsp;</td><td>Automotive Glass service , Taiwan</td><td></td><td></td></tr><tr><td>Ordinary toughened glass</td><td>Automotive Glass service , Taiwan</td><td></td><td></td></tr><tr><td>Thermal paste</td><td>Electrolube</td><td>EG-30&amp;nbsp;</td><td></td></tr><tr><td>Insulation Tape</td><td>Chuan Chi Trading Co. Ltd</td><td>Kapton Tape</td><td></td></tr><tr><td>Sandpaper</td><td>Chuan Chi Trading Co. Ltd</td><td>#2000</td><td></td></tr><tr><td>Heating furnace</td><td>Chung Chuan</td><td>Hong Sen HS-101</td><td></td></tr><tr><td>Electronic scales</td><td>A&amp;amp;D co. Ltd</td><td>GX400</td><td></td></tr><tr><td>Ultrasonic cleaner</td><td>Bransonic</td><td>Bransonic 3510</td><td></td></tr><tr><td>Magnet stirrer</td><td>Yellow line</td><td>MST D S1</td><td></td></tr><tr><td>Data logger&amp;nbsp;</td><td>Yokogawa</td><td>MX-100</td><td></td></tr><tr><td>CCD camera</td><td>JVC</td><td>LY35862-001A</td><td></td></tr><tr><td>Silicon paste</td><td>Permatex</td><td>599BR</td><td></td></tr><tr><td>Power supply</td><td>Gwinstek</td><td>GPR-20H50D</td><td></td></tr><tr><td>Teflon tape&amp;nbsp;</td><td>Chuan Chi Trading Co. Ltd</td><td>CS170000</td><td></td></tr><tr><td>Contact Angle Goniometer</td><td>Sindatek</td><td>Model 100SB</td><td></td></tr><tr><td>Auxiliary Heater</td><td>Chuan Chi Trading Co. Ltd</td><td></td><td></td></tr><tr><td>T- type thermocouples</td><td>Chuan Chi Trading Co. Ltd</td><td></td><td></td></tr><tr><td>Reflux Condenser&amp;nbsp;</td><td>Chuan Chi Trading Co. Ltd</td><td></td><td></td></tr><tr><td>Fiber glass</td><td>Professional Plastics, Taiwan</td><td></td><td></td></tr></tbody></table>

pool-boiling heat-transfer enhancement on cylindrical surfaces with hybrid wettable patterns

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the hybrid wettable pattern. Hybrid wettable patterns were produced by coating superhydrophilic SiO2 on a masked, hydrophobic, cylindrical copper surface. Using de-ionized (DI) water as the working fluid, pool-boiling heat-transfer studies were conducted on the different surface-treated copper cylinders of a 25-mm diameter and a 40-mm length. The experimental results showed that the number of interlines and the orientation of the hybrid wettable pattern influenced the wall superheat and the HTC. By increasing the number of interlines, the HTC was enhanced when compared to the plain surface. Images obtained from the charge-coupled device (CCD) camera indicated that more bubbles formed on the interlines as compared to other parts. The hybrid wettable pattern with the lowermost section being hydrophobic gave the best heat-transfer coefficient (HTC). The experimental results indicated that the bubble dynamics of the surface is an important factor that determines the nucleate boiling.

Havuz kaynama noktalı bir ısı-transfer deneyleri şeması Şekil 5&#39;te gösterilmektedir deney düzeneği kullanılarak bir melez ıslatılabilir silindirik yüzeyi üzerinde gerçekleştirilmiştir. fugalara sayısı ve havuz kaynama performansı üzerinde melez ıslatılabilir desenin oryantasyonu etkisinin araştırılması sırasında havuz kaynama deneysel prosedür protokolü bölümünün aşama 2&#39;de açıklandığı başarılı bir şekilde gerçekleşt...

Watch this Scientific Journal Video about Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns at JoVE.com

Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns

Havuz kaynatma ısı transferi deneyleri ısı transferi katsayısı (HTC) üzerine hibrit ıslanabilir desen etkilerini gözlemlemek için yapılmıştır. araştırma parametreleri fugalara sayısı ve modifiye ıslatılabilir yüzey deseni yönelimi vardır.

Hibrid Sulandınlabilir Desenler Silindirik Yüzeylerde Pool-Kaynama Isı Transferinin Geliştirilmesi

In this study, pool-boiling heat-transfer experiments were performed to investigate the effect of the number of interlines and the orientation of the ...

pool-boiling-heat-transfer-enhancement-on-cylindrical-surfaces-with

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

9.0K Görüntüleme.  National Taiwan University.  Havuz kaynatma ısı transferi deneyleri ısı transferi katsayısı (HTC) üzerine hibrit ıslanabilir desen etkilerini gözlemlemek için yapılmıştır. araştırma parametreleri fugalara sayısı ve modifiye ıslatılabilir yüzey deseni yönelimi vardır. 

Video: Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns

Visualization of High Speed Liquid Jet Impaction on a Moving Surface

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds between 0 and 25 m/sec) and a spinning disk device (for examining surface speeds between 15 and 100 m/sec). The air cannon linear traverse is a pneumatic energy-powered system that is designed to accelerate a metal rail surface mounted on top of a wooden projectile. A pressurized cylinder fitted with a solenoid valve rapidly releases pressurized air into the barrel, forcing the projectile down the cannon barrel. The projectile travels beneath a spray nozzle, which impinges a liquid jet onto its metal upper surface, and the projectile then hits a stopping mechanism. A camera records the jet impingement, and a pressure transducer records the spray nozzle backpressure. The spinning disk set-up consists of a steel disk that reaches speeds of 500 to 3,000 rpm via a variable frequency drive (VFD) motor. A spray system similar to that of the air cannon generates a liquid jet that impinges onto the spinning disc, and cameras placed at several optical access points record the jet impingement. Video recordings of jet impingement processes are recorded and examined to determine whether the outcome of impingement is splash, splatter, or deposition. The apparatuses are the first that involve the high speed impingement of low-Reynolds-number liquid jets on high speed moving surfaces. In addition to its rail industry applications, the described technique may be used for technical and industrial purposes such as steelmaking and may be relevant to high-speed 3D printing.

Two experimental devices for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device and a spinning disk device. The apparatuses are used to determine optimal approaches to the application of liquid friction modifier (LFM) onto rail tracks for top-of-rail friction control.

Bir Hareketli Yüzeyde Yüksek Hızlı Sıvı Jet birikiminin Görselleştirme

Two apparatuses for examining liquid jet impingement on a high-speed moving surface are described: an air cannon device (for examining surface speeds ...

Mühendislik

Measurements of Local Instantaneous Convective Heat Transfer in a Pipe - Single and Two-phase Flow

This manuscript provides step by step description of the manufacturing process of a test section designed to measure the local instantaneous heat transfer coefficient as a function of the liquid flow rate in a transparent pipe. With certain amendments, the approach is extended to gas-liquid flows, with a particular emphasis on the effect of a single elongated (Taylor) air bubble on heat transfer enhancement. A non-invasive thermography technique is applied to measure the instantaneous temperature of a thin metal foil heated electrically. The foil is glued to cover a narrow slot cut in the pipe. The thermal inertia of the foil is small enough to detect the variation in the instantaneous foil temperature. The test section can be moved along the pipe and is long enough to cover a considerable part of the growing thermal boundary layer.
At the beginning of each experimental run, a steady state with a constant water flow rate and heat flux to the foil is attained and serves as the reference. The Taylor bubble is then injected into the pipe. The heat transfer coefficient variations due to the passage of a Taylor bubble propagating in a vertical pipe is measured as function of the distance of the measuring point from the bottom of the moving Taylor bubble. Thus, the results represent the local heat transfer coefficients. Multiple independent runs preformed under identical conditions allow accumulating sufficient data to calculate reliable ensemble-averaged results on the transient convective heat transfer. In order to perform this in a frame of reference moving with the bubble, the location of the bubble along the pipe has to be known at all times. Detailed description of measurements of the length and of the translational velocity of the Taylor bubbles by optical probes is presented.

This manuscript describes methods aimed at measuring the local instantaneous convective heat transfer coefficients in a single or two-phase pipe flow. A simple optical method to determine the length and the propagation velocity of an elongated (Taylor) air bubble moving at a constant velocity is also presented.

Yerel anlık konvektif ısı transferi boru - tek ve iki aşamalı akış ölçümleri

This manuscript provides step by step description of the manufacturing process of a test section designed to measure the local instantaneous heat transfer ...

Uncoupling Coriolis Force and Rotating Buoyancy Effects on Full-Field Heat Transfer Properties of a Rotating Channel

An experimental method for exploring the heat transfer characteristics of an axially rotating channel is proposed. The governing flow parameters that characterize the transport phenomena in a rotating channel are identified via the parametric analysis of the momentum and energy equations referring to a rotating frame of reference. Based on these dimensionless flow equations, an experimental strategy that links the design of the test module, the experimental program and the data analysis is formulated with the attempt to reveal the isolated Coriolis-force and buoyancy effects on heat transfer performances. The effects of Coriolis force and rotating buoyancy are illustrated using the selective results measured from rotating channels with various geometries. While the Coriolis-force and rotating-buoyancy impacts share several common features among the various rotating channels, the unique heat transfer signatures are found in association with the flow direction, the channel shape and the arrangement of heat transfer enhancement devices. Regardless of the flow configurations of the rotating channels, the presented experimental method enables the development of physically consistent heat transfer correlations that permit the evaluation of isolated and interdependent Coriolis-force and rotating-buoyancy effects on the heat transfer properties of rotating channels.

Here, we present an experimental method for decoupling the interdependent Coriolis-force and rotating-buoyancy effects on full-field heat transfer distributions of a rotating channel.

Uncoupling Coriolis kuvveti ve tam-alan ısı üzerinde dönen yüzdürme etkileri dönen bir kanal özelliklerini aktarma

An experimental method for exploring the heat transfer characteristics of an axially rotating channel is proposed. The governing flow parameters that ...

Analyzing Mixing Inhomogeneity in a Microfluidic Device by Microscale Schlieren Technique

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren system is constructed from a Hoffman modulation contrast microscope, which provides easy access to the rear focal plane of the objective lens, by removing the slit plate and replacing the modulator with a knife-edge. The working principle of microscale schlieren technique relies on detecting light deflection caused by variation of refractive index1-3. The deflected light either escapes or is obstructed by the knife-edge to produce a bright or a dark band, respectively. If the refractive index of the mixture varies linearly with its composition, the local change in light intensity in the image plane is proportional to the concentration gradient normal to the optical axis. The micro-schlieren image gives a two-dimensional projection of the disturbed light produced by three-dimensional inhomogeneity.
To accomplish quantitative analysis, we describe a calibration procedure that mixes two fluids in a T-microchannel. We carry out a numerical simulation to obtain the concentration gradient in the T-microchannel that correlates closely with the corresponding micro-schlieren image. By comparison, a relationship between the grayscale readouts of the micro-schlieren image and the concentration gradients presented in a microfluidic device is established. Using this relationship, we are able to analyze the mixing inhomogeneity from associate micro-schlieren image and demonstrate the capability of microscale schlieren technique with measurements in a microfluidic oscillator4. For optically transparent fluids, microscale schlieren technique is an attractive diagnostic tool to provide instantaneous full-field information that retains the three-dimensional features of the mixing process.

Herein, we describe a procedure that employs microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. Through calibration, distribution of concentration gradient can be derived from the micro-schlieren image.

Mikro Schlieren Tekniği ile bir mikroakışkan Aygıt karıştırma homojen Analizi

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren ...

Biyomühendislik

Scalable Stamp Printing and Fabrication of Hemiwicking Surfaces

Hemiwicking is a process where a fluid wets a patterned surface beyond its normal wetting length due to a combination of capillary action and imbibition. This wetting phenomenon is important in many technical fields ranging from physiology to aerospace engineering. Currently, several different techniques exist for fabricating hemiwicking structures. These conventional methods, however, are often time consuming and are difficult to scale-up for large areas or are difficult to customize for specific, nonhomogeneous patterning geometries. The presented protocol provides researchers with a simple, scalable, and cost-effective method for fabricating micro-patterned hemiwicking surfaces. The method fabricates wicking structures through the use of stamp printing, polydimethylsiloxane (PDMS) molding, and thin-film surface coatings. The protocol is demonstrated for hemiwicking with ethanol on PDMS micropillar arrays coated with a 70 nm thick aluminum thin-film.

A simple protocol is provided for the fabrication of hemiwicking structures of varying sizes, shapes, and materials. The protocol uses a combination of physical stamping, PDMS molding, and thin-film surface modifications via common materials deposition techniques.

Ölçeklenebilir pul baskı ve Hemiwicking yüzeyler imalatı

Hemiwicking is a process where a fluid wets a patterned surface beyond its normal wetting length due to a combination of capillary action and imbibition. ...

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping microtextures (GEMs) on them comprising cavities and pillars with reentrant and doubly reentrant features. Specifically, we use SiO2/Si as the model system and share protocols for two-dimensional (2D) designing, photolithography, isotropic/anisotropic etching techniques, thermal oxide growth, piranha cleaning, and storage towards achieving those microtextures. Even though the conventional wisdom indicates that roughening intrinsically wetting surfaces (&#952;o &#60; 90&#176;) renders them even more wetting (&#952;r &#60; &#952;o &#60; 90&#176;), GEMs demonstrate liquid repellence despite the intrinsic wettability of the substrate. For instance, despite the intrinsic wettability of silica &#952;o &#8776; 40&#176; for the water/air system, and &#952;o &#8776; 20&#176; for the hexadecane/air system, GEMs comprising cavities entrap air robustly on immersion in those liquids, and the apparent contact angles for the droplets are &#952;r &#62; 90&#176;. The reentrant and doubly reentrant features in the GEMs stabilize the intruding liquid meniscus thereby trapping the liquid-solid-vapor system in metastable air-filled states (Cassie states) and delaying wetting transitions to the thermodynamically-stable fully-filled state (Wenzel state) by, for instance, hours to months. Similarly, SiO2/Si surfaces with arrays of reentrant and doubly reentrant micropillars demonstrate extremely high contact angles (&#952;r &#8776; 150&#176;&#8211;160&#176;) and low contact angle hysteresis for the probe liquids, thus characterized as superomniphobic. However, on immersion in the same liquids, those surfaces dramatically lose their superomniphobicity and get fully-filled within &#60;1 s. To address this challenge, we present protocols for hybrid designs that comprise arrays of doubly reentrant pillars surrounded by walls with doubly reentrant profiles. Indeed, hybrid microtextures entrap air on immersion in the probe liquids. To summarize, the protocols described here should enable the investigation of GEMs in the context of achieving omniphobicity without chemical coatings, such as perfluorocarbons, which might unlock the scope of inexpensive common materials for applications as omniphobic materials. Silica microtextures could also serve as templates for soft materials.

Rendering SiO2/Si Surfaces Omniphobic by Carving Gas-Entrapping Microtextures Comprising Reentrant and Doubly Reentrant Cavities or Pillars

This work presents microfabrication protocols for achieving cavities and pillars with reentrant and doubly reentrant profiles on SiO2/Si wafers using photolithography and dry etching. Resulting microtextured surfaces demonstrate remarkable liquid repellence, characterized by robust long-term entrapment of air under wetting liquids, despite the intrinsic wettability of silica.

Reentrant ve İki Kat Reentrant Boşlukları veya Sütunlardan Oluşan Gaz-Entrapping Mikrodokuları Oyarak SiO2/Si Yüzeylerin Omnifobik Hale Getirilmesi

We present microfabrication protocols for rendering intrinsically wetting materials repellent to liquids (omniphobic) by creating gas-entrapping ...

Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination

Desalination through direct contact membrane distillation (DCMD) exploits water-repellent membranes to robustly separate counterflowing streams of hot and salty seawater from cold and pure water, thus allowing only pure water vapor to pass through. To achieve this feat, commercial DCMD membranes are derived from or coated with water-repellent perfluorocarbons such as polytetrafluoroethylene (PTFE) and polyvinylidene difluoride (PVDF). However, the use of perfluorocarbons is limiting due to their high cost, non-biodegradability, and vulnerability to harsh operational conditions. Unveiled here is a new class of membranes referred to as gas-entrapping membranes (GEMs) that can robustly entrap air upon immersion in water. GEMs achieve this function by their microstructure rather than their chemical make-up. This work demonstrates a proof-of-concept for GEMs using intrinsically wetting SiO2/Si/SiO2 wafers as the model system; the contact angle of water on SiO2 is &#952;o &#8776; 40&#176;. Silica-GEMs had 300 &#956;m-long cylindrical pores whose diameters at the (2 &#956;m-long) inlet and outlet regions were significantly smaller; this geometrically discontinuous structure, with 90&#176; turns at the inlets and outlets, is known as the &#34;reentrant microtexture&#34;. The microfabrication protocol for silica-GEMs entails designing, photolithography, chrome sputtering, and isotropic and anisotropic etching. Despite the water loving nature of silica, water does not intrude silica-GEMs on submersion. In fact, they robustly entrap air underwater and keep it intact even after six weeks (&#62;106 seconds). On the other hand, silica membranes with simple cylindrical pores spontaneously imbibe water (&#60; 1 s). These findings highlight the potential of the GEMs architecture for separation processes. While the choice of SiO2/Si/SiO2 wafers for GEMs is limited to demonstrating the proof-of-concept, it is expected that the protocols and concepts presented here will advance the rational design of scalable GEMs using inexpensive common materials for desalination and beyond.

Proof-of-Concept for Gas-Entrapping Membranes Derived from Water-Loving SiO2/Si/SiO2 Wafers for Green Desalination

Presented here is a stepwise protocol for realizing gas-entrapping membranes (GEMs) from SiO2/Si wafers using integrated circuit microfabrication technology. When silica-GEMs are immersed in water, the intrusion of water is prevented, despite the water-loving composition of silica.

Su Seven SiO2/Si/SiO2 Gofretlerden Elde Edilen Gaz-Entrapping Membranlar Için Proof-of-Concept Yeşil Tuzdan Arındırma için Gofretler

Desalination through direct contact membrane distillation (DCMD) exploits water-repellent membranes to robustly separate counterflowing streams of hot and ...

Preparation of Free-Surface Hyperbolic Water Vortices

Free surface vortices are present in industry in flow regulation, energy dissipation, and energy generation. Although investigated extensively, detailed experimental data regarding free surface vortices are lacking, particularly regarding the turbulence at the interface. The present paper reports on a special type of free surface vortex first proposed by Walter Schauberger in the 1960s that has an oxygen volumetric mass transfer coefficient exceeding the value of similar systems. This special type of vortex forms in a hyperbolic funnel. Different stable regimes can be stabilized with different hydraulic characteristics. Other advantages of this technology are its energy efficiency, simple design, and scalability. The flow in this hyperbolic funnel is characterized by strong turbulence and an increased surface area of the air-water interface. The local pressure strongly varies along the surface, resulting in a pronounced wavey air-water boundary layer. Due to the helical flow, these perturbations move inward, pulling the boundary layer with them. The resultant pressure gradient draws a certain air volume into the water vortex. The construction of the basic hyperbolic funnel setup and operational examples, including high-speed visualization for three different stable regimes, are presented in this work.

This paper describes how three different water vortex regimes in a hyperbolic Schauberger funnel can be created, their most important characteristics, and how associated parameters such as the oxygen transfer rates can be calculated.

Serbest Yüzeyli Hiperbolik Su Girdaplarının Hazırlanması

Free surface vortices are present in industry in flow regulation, energy dissipation, and energy generation. Although investigated extensively, detailed ...

Testing the Heat Transfer Efficiency of a Finned-tube Heat Exchanger

Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA
Heat exchangers transfer heat from one fluid to another fluid. Multiple classes of heat exchangers exist to fill different needs. Some of the most common types are shell and tube exchangers and plate exchangers1. Shell and tube heat exchangers use a system of tubes through which fluid flows1. One set of tubes contains the liquid to be cooled or heated, while the second set contains the liquid that will either absorb heat or transmit it1. Plate heat exchangers use a similar concept, in which plates are closely joined together with a small gap between each for liquid to flow1. The fluid flowing between the plates alternates between hot and cold so that heat will move into or out of the necessary streams1. These exchangers have large surface areas, so they are usually more efficient1.
The goal for this experiment is to test the heat transfer efficiency of a finned-tube heat exchanger (Figure 1) and compare it to the theoretical efficiency of a heat exchanger without fins. The experimental data will be measured for three different flow rates of monoethylene glycol (MEG). Two different water flow rates for each MEG flow rate will be used. Using the Wilson plot method the heat transfer coefficients will be determined from the experimental data. Additionally, the Reynold&#39;s number and the amount of heat transferred will be compared for flow with and without the fins to evaluate heat transfer efficiency.
<img alt="Figure 1" src="/files/ftp_upload/10437/10437fig1.jpg" /> 
Figure 1: Finned-tube Heat Exchanger. 1) MEG outlet temperature 2) water inlet temperature 3) MEG inlet temperature 4) water outlet temperature 5) water meter 6) MEG accumulation sight glass/cylinder.

Heat Transfer Efficiency Test of a Finned-tube Heat Exchanger

Source: Michael G. Benton and Kerry M. Dooley, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA
Heat exchangers transfer ...

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Kimya Mühendisliği

Quenching and Boiling

Source: Alexander S Rattner, Sanjay Adhikari, and Mahdi Nabil; Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA
Controlled heating followed by rapid cooling is an important element of many materials processing applications. This heat-treating procedure can increase material hardness, which is important for cutting tools or surfaces in high wear environments. The rapid cooling stage is called quenching, and is often performed by immersing materials in a fluid bath (often water or oil). Quenching heat transfer can occur due to forced convection - when the action of rapidly moving material through coolant drives the heat transfer process, and due to free convection - when the reduced density of hot fluid near the material surface causes buoyancy-driven circulation and heat transfer. At high material temperatures, the coolant can boil, leading to increased heat transfer effectiveness. However, when extremely hot materials are quenched, they can be blanketed in relatively low thermal conductivity coolant vapor, leading to poor heat transfer.
In this experiment, quenching heat transfer will be measured for a heated copper cylinder, which is representative of small heat-treated parts. The transient sample temperature profile will be measured during quenching and compared with theoretical results for free convection heat transfer. Boiling phenomena will also be investigated qualitatively.

Quenching, Boiling, Convection and Nusselt Number

Source: Alexander S Rattner, Sanjay Adhikari, and Mahdi Nabil; Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, ...

Hibrid Sulandınlabilir Desenler Silindirik Yüzeylerde Pool-Kaynama Isı Transferinin Geliştirilmesi

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