Nanofluids and critical heat flux, experimental and analytical study

Golubovic, Mihajlo; Hettiarachchi, Hiroshan; Worek, William M.; Minkowycz, W. J.

doi:10.1016/j.applthermaleng.2008.05.005

Cited by 132 publications

(53 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Hence we can deduce that particle volume concentration does not have a major effect on the surface tension of the nanofluids. The experimental results of Golubovic et al (2009) and Kim et al (2007) have shown that the surface tensions of the Al 2 O 3 nanofluids without surfactant is independent on concentration and has the same values as that of pure water. In our prepared nanofluids, the surfactant, CTAB was added to obtain a well-dispersed suspension.…”

Section: Effect Of Particle Size On Viscositymentioning

confidence: 88%

“…Pantzali et al (2009) used the pendant droplet method to measure the surface tension of the CuO water-based nanofluids. The other common method to measure surface tension is the capillary method (Golubovic et al, 2009). The main component of the device is a capillary tube in which the liquids would show a significant rise with a meniscus due to the surface tension in order to balance the gravity force.…”

Section: Surface Tension Of Nanofluidsmentioning

confidence: 99%

See 1 more Smart Citation

Thermal Property Measurement of Al2O3-Water Nanofluids

Duan¹

2012

Smart Nanoparticles Technology

View full text Add to dashboard Cite

Section: Effect Of Particle Size On Viscositymentioning

confidence: 88%

Section: Surface Tension Of Nanofluidsmentioning

confidence: 99%

Thermal Property Measurement of Al2O3-Water Nanofluids

Duan¹

2012

Smart Nanoparticles Technology

View full text Add to dashboard Cite

“…Şekil 7'de görüldüğü gibi, özellikle silika deneyleri sonrasında numune yüzeyinde görünür ancak homojen olmayan bir nano partikül tabakası tespit edilmiş ve yüzey karakteristiklerinde önemli değişiklik meydana gelmiştir. Bu nedenle, soğuma eğrilerindeki sapmanın (erken soğumanın) temel sebebi, nano akışkanlarla değil değişen yüzey karakteristikleriyle ilgilidir [20][21][22][23]. Bu durumu doğrulamak için test numunesinin yüzeyinden temas açıları (θ) ölçülmüştür (KSV, Cam-101 Scientific Inst.).…”

Section: Hata Analizi (Error Analysis)unclassified

“…Şekil 8'de görüldüğü gibi, nano akışkan deneyleri sonrasında yüzey temas açısı önemli ölçüde azalmıştır. Bazı araştırmacılar da temas açılarında düşüş gözlemişlerdir ki bu durum yüzeydeki aktif buhar çekirdeklerinin sayısında düşüşe neden olmuştur [12,20,[24][25][26][27]. Araştırmacılar düşük partikül konsantrasyonlarında bile (<0.01vol.%) CHF değerinde %250'ye varan önemli artışlar gözlemişlerdir [28][29][30].…”

Section: Hata Analizi (Error Analysis)unclassified

Küresel Yüzeyler Etrafinda Nano Akişkanlarda Havuz Kaynama Isi Transferi̇ni̇n Deneysel İncelenmesi̇

Çiloğlu¹,

Bölükbaşi²,

Çifci³

2015

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

View full text Add to dashboard Cite

ÖZETBu çalışmada, atmosfer basıncı altında ve doyma şartlarında nano akışkanlarla su verilerek soğutulan yüksek sıcaklıktaki küresel yüzeyler etrafında havuz kaynama ısı transferi deneysel olarak incelenmiştir. Deneylerde %0,01, %0,05 ve %0,1 olmak üzere üç farklı hacimsel konsantrasyonda saf su esaslı silika, alümina, titania ve bakır oksit nano akışkanları kullanılmıştır. Bronz malzemeden yapılmış küresel test numunesi yüksek sıcaklıklara kadar ısıtıldıktan sonra, doymuş şartlardaki nano akışkan süspansiyonlarına aniden daldırmıştır. Numuneye ait sıcaklık-zaman verileri ile soğuma eğrileri çizilmiş ve kaynama eğrileri elde edilmiştir. Deneysel sonuçlar, test numunesinin soğuma performansının nano akışkan tipine ve konsantrasyonuna bağlı olarak değiştiğini göstermiştir. İlk su verme testlerinde saf suya yakın değerler elde edilmesine rağmen, nano akışkanlarda tekrarlı testler ile soğuma süresinin önemli ölçüde kısaldığı görülmüştür. Bu etki nano partikül konsantrasyonuyla artmıştır. Özellikle silika nano akışkanı için tekrarlı su verme testleri ile film kaynama kaybolmuş ve kritik ısı akısı önemli derecede artmıştır. Deneysel sonuçlar, ayrıca, çekirdek havuz kaynama ısı transferinde tüm nano akışkanlar için önemli bir değişimin olmadığını göstermiştir. Sonuç olarak, nano akışkanlar ile su verme testleri sonrasında, test yüzeyi üzerinde biriken nano partiküllerin yüzeyin ıslatabilirliğini artırdığı ve böylece kritik ısı akısında artışa neden olduğu belirlenmiştir.Anahtar Kelimeler: Isı transferi, havuz kaynama, nano akışkanlar, küresel yüzeyler EXPERIMENTAL INVESTIGATION OF POOL BOILING HEAT TRANSFER IN NANOFLUIDS AROUND SPHERICAL SURFACES ABSTRACTIn this study, the pool boiling heat transfer around spherical surfaces with high temperature quenched by nanofluids at saturated conditions and under atmospheric pressure was experimentally investigated. In the experiments, pure water-based silica, alumina, titania and copper oxide nanofluids with three different volumetric particle concentrations (0.01, 0.05 and 0.1%) were used. After the spherical test specimen made up off brass material was heated at high temperatures, it was suddenly plunged into the nanofluid suspensions at saturated conditions. Using the temperature-time data of the specimen, the cooling curves were drawn and the boiling curves were obtained. The experimental results showed that the cooling performance of test specimen depended on the type of nanofluids and nanoparticle concentration. In the first quenching tests, although the cooling trend were nearly identical to that in pure water, it was observed that the cooling time was considerably shortened with the repetition tests in nanofluids. This effect enhanced with the nanoparticle concentrations. For silica nanofluids, especially, the film boiling region vanished during the repetition tests and the critical heat flux dramatically increased. The experimental results also showed that a considerable change in nucleate pool boiling heat transfer was not observed for all nanofluids. Consequently, it ...

show abstract

“…[18,19] It has also been reported that the size of the particles used can affect the heat transfer properties of the fluid. Anoop et al reported that smaller particles have greater heat transfer coefficient compared to larger particles in the developing region of internal flow.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of heat transfer by water–Al₂O₃and water–TiO₂nanofluids jet impingement in cooling hot steel surface

Nayak

Mishra

Parashar

2016

Journal of Experimental Nanoscience

View full text Add to dashboard Cite

Two different nanofluids, namely waterÀAl 2 O 3 and waterÀTiO 2 , were impinged in the form of jet on hot steel surface to remove high heat flux, and their performance was compared. The dimension of the test steel sample was 120 mm £ 120 mm and 4 mm thickness. Four K-type thermocouples were embedded on the bottom surface of the plate to measure the transient temperature distribution. The time-temperature data were recorded by the help of a data acquisition system (make: CHINO, model: KR2000), and the results were analysed by ZAILA application software. Effect of impinging nanofluids with weight concentrations of 0.01%, 0.03%, 0.05% and 0.07% Al 2 O 3 and TiO 2 nanoparticles on heat transfer from the hot surface was tested. The surface heat transfer coefficient (HTC) was computed from the time-temperature history recorded during experimentation. Experimental results revealed that addition of nanoparticles to the base fluid (water) surprisingly enhanced the heat transfer rate and HTC as expected. The heat transfer rate increased up to certain limit of nanoparticle concentrations, and then declined. Application of nanofluids for the steel strip cooling was found very effective in terms of heat transfer phenomena as compared to the conventional fluid cooling methods.

show abstract

Nanofluids and critical heat flux, experimental and analytical study

Cited by 132 publications

References 18 publications

Thermal Property Measurement of Al2O3-Water Nanofluids

Thermal Property Measurement of Al2O3-Water Nanofluids

Küresel Yüzeyler Etrafinda Nano Akişkanlarda Havuz Kaynama Isi Transferi̇ni̇n Deneysel İncelenmesi̇

Enhancement of heat transfer by water–Al₂O₃and water–TiO₂nanofluids jet impingement in cooling hot steel surface

Contact Info

Product

Resources

About

Nanofluids and critical heat flux, experimental and analytical study

Cited by 132 publications

References 18 publications

Thermal Property Measurement of Al2O3-Water Nanofluids

Thermal Property Measurement of Al2O3-Water Nanofluids

Küresel Yüzeyler Etrafinda Nano Akişkanlarda Havuz Kaynama Isi Transferi̇ni̇n Deneysel İncelenmesi̇

Enhancement of heat transfer by water–Al2O3and water–TiO2nanofluids jet impingement in cooling hot steel surface

Contact Info

Product

Resources

About

Enhancement of heat transfer by water–Al₂O₃and water–TiO₂nanofluids jet impingement in cooling hot steel surface