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Author

Hyomin Jeong

Bio: Hyomin Jeong is an academic researcher from Gyeongsang National University. The author has contributed to research in topics: Nanofluid & Heat transfer. The author has an hindex of 22, co-authored 222 publications receiving 1921 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, a two-phase mixture model has been chosen to study forced convective heat transfer of nanofluid introducing a new concept of heat transfer enhancement in this article.

198 citations

Journal ArticleDOI
TL;DR: In this paper, a significant enhancement in the thermal conductivity of silver-nanoparticle-based aqueous nanofluids with the addition of negligible amounts of multi-walled carbon nanotubes (MWCNTs) was reported.

187 citations

Journal ArticleDOI
TL;DR: In this paper, a new approach of attaining the optimum grinding condition of a planetary ball mill and simple method for purifying multi-walled carbon nanotubes (MWCNTs) to investigate the dispersion characteristics of MWCNTs was presented.

139 citations

Journal ArticleDOI
TL;DR: The overall result shows that the enhancement in normalized thermal conductivity of hybrid nanofluids is still not so sharp though the absorbance and other qualities show much better comparing mono type nan ofluids.
Abstract: Synthesis of water based Al2O3-MWCNTs hybrid nanofluids have been investigated and characterized. Al2O3-MWCNTs nanoparticles in weight proportion of 97.5:2.5 to 90:10 have been studied over 1% to 6% weight concentration. Dispersion quality of nanofluids is assured by additional synthesis process like acids treatment and grinding of MWCNTs by planetary ball mill. The effects of ground and non-ground MWCNTs over dispersion quality and thermal conductivity have been investigated. Sedimentation effect of hybrid nanofluids with time length has been studied by sample visualization and TEM micrographs. The augmentative absorbance and thermal conductivity of hybrid nanofluids have been compared with pure Al2O3/water nanofluids. The overall result shows that the enhancement in normalized thermal conductivity of hybrid nanofluids is still not so sharp though the absorbance and other qualities show much better comparing mono type nanofluids. Hybrid nanofluids with spherical particles show a smaller increase in thermal conductivity comparing cylindrical shape particles.

136 citations

Journal ArticleDOI
TL;DR: In this paper, the surface/shape of newly synthesized "Ag" nanoparticles is modified by planetary ball milling and the flattened particles are incorporated with the combination of small (15 nm) and large (300 nm) TiO2 nanoparticles in an aqueous solution.
Abstract: Nanofluid is a colloidal suspension which has received great attention over the past two decades, but its limited heat transfer enhancement is a matter of concern for industrial applications. We demonstrate an improvement in the thermal conductivity of TiO2 nanofluids with an addition of negligible amounts of modified silver “Ag” nanoparticles. In this work, the surface/shape of newly synthesized “Ag” nanoparticles is modified by planetary ball milling. Then, to enhance the thermal conductivity of TiO2 nanofluids, the flattened “Ag” particles are incorporated with the combination of small (15 nm) and large (300 nm) TiO2 nanoparticles in an aqueous solution. The thermal conductivities of Ag/TiO2–water nanofluids with various weight concentrations are measured at temperatures ranging from 15 to 40 °C. As a result, the present study confirms that the thermal conductivity of TiO2 based solution can be improved by introducing the flattened “Ag” particles.

134 citations


Cited by
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01 Jan 2007

1,932 citations

Journal ArticleDOI
TL;DR: In this paper, a review summarizes recent researches on synthesis, thermophysical properties, heat transfer and pressure drop characteristics, possible applications and challenges of hybrid nanofluids, and showed that proper hybridization may make the hybrid nanoparticles very promising for heat transfer enhancement, however, lot of research works are still needed in the fields of preparation and stability, characterization and applications to overcome the challenges.
Abstract: Researches on the nanofluids have been increased very rapidly over the past decade. In spite of some inconsistency in the reported results and insufficient understanding of the mechanism of the heat transfer in nanofluids, it has been emerged as a promising heat transfer fluid. In the continuation of nanofluids research, the researchers have also tried to use hybrid nanofluid recently, which is engineered by suspending dissimilar nanoparticles either in mixture or composite form. The idea of using hybrid nanofluids is to further improvement of heat transfer and pressure drop characteristics by trade-off between advantages and disadvantages of individual suspension, attributed to good aspect ratio, better thermal network and synergistic effect of nanomaterials. This review summarizes recent researches on synthesis, thermophysical properties, heat transfer and pressure drop characteristics, possible applications and challenges of hybrid nanofluids. Review showed that proper hybridization may make the hybrid nanofluids very promising for heat transfer enhancement, however, lot of research works is still needed in the fields of preparation and stability, characterization and applications to overcome the challenges.

846 citations

01 Nov 1999
TL;DR: In this paper, two forms of ventilation are discussed: mixing ventilation and displacement ventilation, where the interior is at an approximately uniform temperature and there is strong internal stratification, respectively, and the effects of wind on them are examined.
Abstract: Natural ventilation of buildings is the flow generated by temperature differences and by the wind. The governing feature of this flow is the exchange between an interior space and the external ambient. Although the wind may often appear to be the dominant driving mechanism, in many circumstances temperature variations play a controlling feature on the ventilation since the directional buoyancy force has a large influence on the flow patterns within the space and on the nature of the exchange with the outside. Two forms of ventilation are discussed: mixing ventilation, in which the interior is at an approximately uniform temperature, and displacement ventilation, where there is strong internal stratification. The dynamics of these buoyancy-driven flows are considered, and the effects of wind on them are examined. The aim behind this work is to give designers rules and intuition on how air moves within a building; the research reveals a fascinating branch of fluid mechanics.

559 citations

01 Jan 2016
TL;DR: The principles of enhanced heat transfer is universally compatible with any devices to read and is available in the book collection an online access to it is set as public so you can get it instantly.
Abstract: Thank you very much for reading principles of enhanced heat transfer. As you may know, people have look numerous times for their chosen books like this principles of enhanced heat transfer, but end up in malicious downloads. Rather than reading a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their desktop computer. principles of enhanced heat transfer is available in our book collection an online access to it is set as public so you can get it instantly. Our books collection spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Merely said, the principles of enhanced heat transfer is universally compatible with any devices to read.

553 citations