Author
Seung-Hyun Lee
Bio: Seung-Hyun Lee is an academic researcher from Korea Aerospace University. The author has contributed to research in topics: Nanofluid & Thermal conductivity. The author has an hindex of 9, co-authored 16 publications receiving 1110 citations.
Papers
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Massachusetts Institute of Technology1, Illinois Institute of Technology2, Franklin W. Olin College of Engineering3, Kent State University4, Rensselaer Polytechnic Institute5, Texas A&M University6, Ulsan National Institute of Science and Technology7, Tokyo Institute of Technology8, University of Naples Federico II9, Sasol10, University of Leeds11, University of Pittsburgh12, Indian Institute of Technology Madras13, Université libre de Bruxelles14, Silesian University of Technology15, North Carolina State University16, IBM17, ETH Zurich18, The Chinese University of Hong Kong19, Stanford University20, University of Puerto Rico at Mayagüez21, South Dakota School of Mines and Technology22, Korea Aerospace University23, Nanyang Technological University24, Helmut Schmidt University25, National Institute of Standards and Technology26, Korea University27, Indian Institute of Technology Kharagpur28, Indira Gandhi Centre for Atomic Research29, Queen Mary University of London30, Argonne National Laboratory31
TL;DR: The International Nanofluid Property Benchmark Exercise (INPBE) as mentioned in this paper was held in 1998, where the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or "nanofluids" was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady state methods, and optical methods.
Abstract: This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.
942 citations
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TL;DR: In this paper, the effect of nanoparticle shape on suspension stability was quantitatively examined using the laser-scattering method rather than the zeta-potential measurement or the sedimentation test.
79 citations
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TL;DR: In this paper, the extinction coefficients of water-based multi-walled carbon nanotubes (MWCNT) nanofluids for application in direct-absorption solar collectors (DASC) were investigated.
63 citations
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TL;DR: In this article, the authors analyzed the efficiency of a volumetric receiver for absorbing solar thermal energy considering the experimentally measured extinction coefficient of aqueous suspensions of multi-walled carbon nanotubes (MWCNT) according to the wavelength from 200 to 2000 nm.
46 citations
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TL;DR: In this paper, the shape of nanoparticles in working nanofluids significantly affects the thermal resistance of the flat-plate heat pipes, and the authors discuss why nanoparticle shape in nanoparticles reduces thermal resistance.
43 citations
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TL;DR: The International Nanofluid Property Benchmark Exercise (INPBE) as discussed by the authors was held in 1998, where the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or "nanofluids" was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady state methods, and optical methods.
Abstract: This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was measured by over 30 organizations worldwide, using a variety of experimental approaches, including the transient hot wire method, steady-state methods, and optical methods. The nanofluids tested in the exercise were comprised of aqueous and nonaqueous basefluids, metal and metal oxide particles, near-spherical and elongated particles, at low and high particle concentrations. The data analysis reveals that the data from most organizations lie within a relatively narrow band (±10% or less) about the sample average with only few outliers. The thermal conductivity of the nanofluids was found to increase with particle concentration and aspect ratio, as expected from classical theory. There are (small) systematic differences in the absolute values of the nanofluid thermal conductivity among the various experimental approaches; however, such differences tend to disappear when the data are normalized to the measured thermal conductivity of the basefluid. The effective medium theory developed for dispersed particles by Maxwell in 1881 and recently generalized by Nan et al. [J. Appl. Phys. 81, 6692 (1997)], was found to be in good agreement with the experimental data, suggesting that no anomalous enhancement of thermal conductivity was achieved in the nanofluids tested in this exercise.
881 citations
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TL;DR: Nanofluids have seen enormous growth in popularity since they were proposed by Choi in 1995 as mentioned in this paper, and there were nearly 700 research articles where the term nanofluid was used in the title, showing rapid growth from 2006 (175) and 2001 (10).
Abstract: Nanofluids—a simple product of the emerging world of nanotechnology—are suspensions of nanoparticles (nominally 1–100 nm in size) in conventional base fluids such as water, oils, or glycols. Nanofluids have seen enormous growth in popularity since they were proposed by Choi in 1995. In the year 2011 alone, there were nearly 700 research articles where the term nanofluid was used in the title, showing rapid growth from 2006 (175) and 2001 (10). The first decade of nanofluid research was primarily focused on measuring and modeling fundamental thermophysical properties of nanofluids (thermal conductivity, density, viscosity, heat transfer coefficient). Recent research, however, explores the performance of nanofluids in a wide variety of other applications. Analyzing the available body of research to date, this article presents recent trends and future possibilities for nanofluids research and suggests which applications will see the most significant improvement from employing nanofluids.
679 citations
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TL;DR: In this article, the effect of nanoparticle volume fraction on thermal conductivity and dynamic viscosity of Ag-MgO/water hybrid nanofluid with the particle diameter of 40(mgO) and 25(Ag) nm was investigated.
461 citations
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TL;DR: Focusing mainly on dilute suspensions of well-dispersed spherical nanoparticles in water or ethylene glycol, recent experimental observations, associated measurement techniques, and new theories as well as useful correlations have been reviewed.
Abstract: Nanofluids, i.e., well-dispersed (metallic) nanoparticles at low- volume fractions in liquids, may enhance the mixture’s thermal conductivity, knf, over the base-fluid values. Thus, they are potentially useful for advanced cooling of micro-systems. Focusing mainly on dilute suspensions of well-dispersed spherical nanoparticles in water or ethylene glycol, recent experimental observations, associated measurement techniques, and new theories as well as useful correlations have been reviewed. It is evident that key questions still linger concerning the best nanoparticle-and-liquid pairing and conditioning, reliable measurements of achievable knf values, and easy-to-use, physically sound computer models which fully describe the particle dynamics and heat transfer of nanofluids. At present, experimental data and measurement methods are lacking consistency. In fact, debates on whether the anomalous enhancement is real or not endure, as well as discussions on what are repeatable correlations between knf and temperature, nanoparticle size/shape, and aggregation state. Clearly, benchmark experiments are needed, using the same nanofluids subject to different measurement methods. Such outcomes would validate new, minimally intrusive techniques and verify the reproducibility of experimental results. Dynamic knf models, assuming non-interacting metallic nano-spheres, postulate an enhancement above the classical Maxwell theory and thereby provide potentially additional physical insight. Clearly, it will be necessary to consider not only one possible mechanism but combine several mechanisms and compare predictive results to new benchmark experimental data sets.
434 citations