Les Inscriptions à la Bibliothèque sont ouvertes en
ligne via le site: https://biblio.enp.edu.dz
Les Réinscriptions se font à :
• La Bibliothèque Annexe pour les étudiants en
2ème Année CPST
• La Bibliothèque Centrale pour les étudiants en Spécialités
A partir de cette page vous pouvez :
Retourner au premier écran avec les recherches... |
Détail de l'auteur
Auteur W. Escher
Documents disponibles écrits par cet auteur
Affiner la rechercheExperimental investigation of an ultrathin manifold microchannel heat sink for liquid-cooled chips / W. Escher in Journal of heat transfer, Vol. 132 N° 8 (Août 2010)
[article]
in Journal of heat transfer > Vol. 132 N° 8 (Août 2010) . - pp. [081402-1/10]
Titre : Experimental investigation of an ultrathin manifold microchannel heat sink for liquid-cooled chips Type de document : texte imprimé Auteurs : W. Escher, Auteur ; T. Brunschwiler, Auteur ; B. Michel, Auteur Article en page(s) : pp. [081402-1/10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Manifold Microchannels Impinging jet Heat transfer Electronics cooling Index. décimale : 536 Chaleur. Thermodynamique Résumé : We report an experimental investigation of a novel, high performance ultrathin manifold microchannel heat sink. The heat sink consists of impinging liquid slot-jets on a structured surface fed with liquid coolant by an overlying two-dimensional manifold. We developed a fabrication and packaging procedure to manufacture prototypes by means of standard microprocessing. A closed fluid loop for precise hydrodynamic and thermal characterization of six different test vehicles was built. We studied the influence of the number of manifold systems, the width of the heat transfer microchannels, the volumetric flow rate, and the pumping power on the hydrodynamic and thermal performance of the heat sink. A design with 12.5 manifold systems and 25 µm wide microchannels as the heat transfer structure provided the optimum choice of design parameters. For a volumetric flow rate of 1.3 l/min we demonstrated a total thermal resistance between the maximum heater temperature and fluid inlet temperature of 0.09 cm2 K/W with a pressure drop of 0.22 bar on a 2×2 cm2 chip. This allows for cooling power densities of more than 700 W/cm2 for a maximum temperature difference between the chip and the fluid inlet of 65 K. The total height of the heat sink did not exceed 2 mm, and includes a 500 µm thick thermal test chip structured by 300 µm deep microchannels for heat transfer. Furthermore, we discuss the influence of elevated fluid inlet temperatures, allowing possible reuse of the thermal energy, and demonstrate an enhancement of the heat sink cooling efficiency of more than 40% for a temperature rise of 50 K.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Experimental investigation of an ultrathin manifold microchannel heat sink for liquid-cooled chips [texte imprimé] / W. Escher, Auteur ; T. Brunschwiler, Auteur ; B. Michel, Auteur . - pp. [081402-1/10].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 132 N° 8 (Août 2010) . - pp. [081402-1/10]
Mots-clés : Manifold Microchannels Impinging jet Heat transfer Electronics cooling Index. décimale : 536 Chaleur. Thermodynamique Résumé : We report an experimental investigation of a novel, high performance ultrathin manifold microchannel heat sink. The heat sink consists of impinging liquid slot-jets on a structured surface fed with liquid coolant by an overlying two-dimensional manifold. We developed a fabrication and packaging procedure to manufacture prototypes by means of standard microprocessing. A closed fluid loop for precise hydrodynamic and thermal characterization of six different test vehicles was built. We studied the influence of the number of manifold systems, the width of the heat transfer microchannels, the volumetric flow rate, and the pumping power on the hydrodynamic and thermal performance of the heat sink. A design with 12.5 manifold systems and 25 µm wide microchannels as the heat transfer structure provided the optimum choice of design parameters. For a volumetric flow rate of 1.3 l/min we demonstrated a total thermal resistance between the maximum heater temperature and fluid inlet temperature of 0.09 cm2 K/W with a pressure drop of 0.22 bar on a 2×2 cm2 chip. This allows for cooling power densities of more than 700 W/cm2 for a maximum temperature difference between the chip and the fluid inlet of 65 K. The total height of the heat sink did not exceed 2 mm, and includes a 500 µm thick thermal test chip structured by 300 µm deep microchannels for heat transfer. Furthermore, we discuss the influence of elevated fluid inlet temperatures, allowing possible reuse of the thermal energy, and demonstrate an enhancement of the heat sink cooling efficiency of more than 40% for a temperature rise of 50 K.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] On the cooling of electronics with nanofluids / W. Escher in Journal of heat transfer, Vol. 133 N° 5 (Mai 2011)
[article]
in Journal of heat transfer > Vol. 133 N° 5 (Mai 2011) . - pp. [051401/1-11]
Titre : On the cooling of electronics with nanofluids Type de document : texte imprimé Auteurs : W. Escher, Auteur ; T. Brunschwiler, Auteur ; N. Shalkevich, Auteur Année de publication : 2011 Article en page(s) : pp. [051401/1-11] Note générale : Physique Langues : Anglais (eng) Mots-clés : Nanofluid Nanoparticle Suspension Thermal conductivity Convection heat transfer Electronics cooling Experiment Index. décimale : 536 Chaleur. Thermodynamique Résumé : Nanofluids have been proposed to improve the performance of microchannel heat sinks. In this paper, we present a systematic characterization of aqueous silica nanoparticle suspensions with concentrations up to 31 vol %. We determined the particle morphology by transmission electron microscope imaging and its dispersion status by dynamic light scattering measurements. The thermophysical properties of the fluids, namely, their specific heat, density, thermal conductivity, and dynamic viscosity were experimentally measured. We fabricated microchannel heat sinks with three different channel widths and characterized their thermal performance as a function of volumetric flow rate for silica nanofluids at concentrations by volume of 0%, 5%, 16%, and 31%. The Nusselt number was extracted from the experimental results and compared with the theoretical predictions considering the change of fluids bulk properties. We demonstrated a deviation of less than 10% between the experiments and the predictions. Hence, standard correlations can be used to estimate the convective heat transfer of nanofluids. In addition, we applied a one-dimensional model of the heat sink, validated by the experiments. We predicted the potential of nanofluids to increase the performance of microchannel heat sinks. To this end, we varied the individual thermophysical properties of the coolant and studied their impact on the heat sink performance. We demonstrated that the relative thermal conductivity enhancement must be larger than the relative viscosity increase in order to gain a sizeable performance benefit. Furthermore, we showed that it would be preferable to increase the volumetric heat capacity of the fluid instead of increasing its thermal conductivity.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...] [article] On the cooling of electronics with nanofluids [texte imprimé] / W. Escher, Auteur ; T. Brunschwiler, Auteur ; N. Shalkevich, Auteur . - 2011 . - pp. [051401/1-11].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 5 (Mai 2011) . - pp. [051401/1-11]
Mots-clés : Nanofluid Nanoparticle Suspension Thermal conductivity Convection heat transfer Electronics cooling Experiment Index. décimale : 536 Chaleur. Thermodynamique Résumé : Nanofluids have been proposed to improve the performance of microchannel heat sinks. In this paper, we present a systematic characterization of aqueous silica nanoparticle suspensions with concentrations up to 31 vol %. We determined the particle morphology by transmission electron microscope imaging and its dispersion status by dynamic light scattering measurements. The thermophysical properties of the fluids, namely, their specific heat, density, thermal conductivity, and dynamic viscosity were experimentally measured. We fabricated microchannel heat sinks with three different channel widths and characterized their thermal performance as a function of volumetric flow rate for silica nanofluids at concentrations by volume of 0%, 5%, 16%, and 31%. The Nusselt number was extracted from the experimental results and compared with the theoretical predictions considering the change of fluids bulk properties. We demonstrated a deviation of less than 10% between the experiments and the predictions. Hence, standard correlations can be used to estimate the convective heat transfer of nanofluids. In addition, we applied a one-dimensional model of the heat sink, validated by the experiments. We predicted the potential of nanofluids to increase the performance of microchannel heat sinks. To this end, we varied the individual thermophysical properties of the coolant and studied their impact on the heat sink performance. We demonstrated that the relative thermal conductivity enhancement must be larger than the relative viscosity increase in order to gain a sizeable performance benefit. Furthermore, we showed that it would be preferable to increase the volumetric heat capacity of the fluid instead of increasing its thermal conductivity.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&smode=strresults& [...]