Author
C.L. Tien
Bio: C.L. Tien is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Heat transfer & Laminar flow. The author has an hindex of 24, co-authored 43 publications receiving 2192 citations.
Papers
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TL;DR: In this paper, the authors investigated non-Darcian flow and heat transfer in high-porosity fibrous media and showed that the porous medium enhances heat transfer from a surface as compared to predicted results for slug or for laminar flow in a channel.
344 citations
206 citations
TL;DR: In this paper, Laminar steady-state natural convection in a two-dimensional rectangular open cavity is investigated numerically, and is shown that outgoing flow patterns and the heat transfer results are governed by strong characteristics of the heated cavity.
186 citations
TL;DR: In this paper, the design, fabrication and testing of a novel thermoelectric device comprised of arrays of silicon nanowires embedded in a polymer matrix was discussed, where parylene, a low thermal conductivity and extremely conformal polymer, was embedded within the arrays.
Abstract: This paper discusses the design, fabrication and testing of a novel thermoelectric device comprised of arrays of silicon nanowires embedded in a polymer matrix. By exploiting the low-thermal conductivity of the composite and presumably high-power factor of the nanowires, a thermoelectric figure of merit, higher than the corresponding bulk value, should result. Arrays were first synthesized using a vapor-liquid-solid (VLS) process leading to one-dimensional (1-D) growth of single-crystalline nanowires. To provide structural support while maintaining thermal isolation between nanowires, parylene, a low thermal conductivity and extremely conformal polymer, was embedded within the arrays. Mechanical polishing and oxygen plasma etching techniques were used to expose the nanowire tips and a metal contact was deposited on the top surface. Scanning electron micrographs (SEMs) illustrate the results of the fabrication processes. Using a modification of the 3/spl omega/ technique, the effective thermal conductivity of the nanowire matrix was measured and 1 V characteristics were also demonstrated. An assessment of the suitability of this nanocomposite for high thermoelectric performance devices is given.
174 citations
TL;DR: In this paper, a hydrodynamic model of stagnation flow is proposed for saturated nucleate boiling over a flat surface, and a relation between the heat-transfer coefficient and the thermal boundary-layer thickness induced by rising bubbles is obtained, and good agreement with measured results in the low heat-flux region is indicated.
128 citations
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TL;DR: In this article, the authors proposed two different approaches for deriving heat transfer correlation of the nanofluid, and investigated the mechanism of heat transfer enhancement of the nano-fluid.
2,355 citations
TL;DR: In this article, the effective thermal conductivity (ke), permeability (K), and inertial coefficient (f) of high porosity metal foams were derived by considering a circular blob of metal at the intersection of two fibers.
998 citations
TL;DR: In this paper, an experimental and numerical study of forced convection in high porosity (e∼0.89-0.97) metal foams was conducted using air as the fluid medium.
Abstract: We report an experimental and numerical study of forced convection in high porosity (e∼0.89-0.97) metal foams. Experiments have been conducted with aluminum metal foams in a variety of porosities and pore densities using air as the fluid medium. Nusselt number data has been obtained as a function of the pore Reynolds number. In the numerical study, a semi-empirical volume-averaged form of the governing equations is used. The velocity profile is obtained by adapting an exact solution to the momentum equation. The energy transport is modeled without invoking the assumption of local thermal equilibrium. Models for the thermal dispersion conductivity, k d , and the interstitial heat transfer coefficient, h sf , are postulated based on physical arguments. The empirical constants in these models are determined by matching the numerical results with the experimental data obtained in this study as well as those in the open literature. Excellent agreement is achieved in the entire range of the parameters studied, indicating that the proposed treatment is sufficient to model forced convection in metal foams for most practical applications
911 citations
TL;DR: In this article, a review of the knowledge of aerogel insulation in general and for building applications in particular is given, where the possibility of high transmittances in the solar spectrum is of high interest for the construction sector.
819 citations
TL;DR: In this article, the influence of surface waves on the thermally excited electromagnetic field is discussed. And the authors introduce the fluctuation-dissipation theorem that allows to model the fluctuating electromagnetic fields.
805 citations