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Journal of heat transfer: Transactions of the ASME |
Dépouillements
Ajouter le résultat dans votre panierTemperature created by a tilted moving heat source / Valerian Nemchinsky in Journal of heat transfer, Vol. 133 N° 2 (Fevrier 2011)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021301/1-7]
Titre : Temperature created by a tilted moving heat source : heating line and cylinder Type de document : texte imprimé Auteurs : Valerian Nemchinsky, Auteur Année de publication : 2011 Article en page(s) : pp. [021301/1-7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat conduction Cutting Peclet number Moving heat source Tilted heat source Index. décimale : 536 Chaleur. Thermodynamique Résumé : Temperatures created by a moving tilted line and a moving tilted cylinder are considered. Analytical expressions for low Peclet (Pe<<1) and high Peclet (Pe>>1) numbers are obtained for the whole range of possible tilt angles. These expressions almost overlap: It is shown that these analytical expressions describe very well the results of numerical calculations at any Peclet numbers except for a very narrow range of Pe close to unity. A method of calculation of the cut shape (variation of the tilt angle inside the cut) is discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Temperature created by a tilted moving heat source : heating line and cylinder [texte imprimé] / Valerian Nemchinsky, Auteur . - 2011 . - pp. [021301/1-7].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021301/1-7]
Mots-clés : Heat conduction Cutting Peclet number Moving heat source Tilted heat source Index. décimale : 536 Chaleur. Thermodynamique Résumé : Temperatures created by a moving tilted line and a moving tilted cylinder are considered. Analytical expressions for low Peclet (Pe<<1) and high Peclet (Pe>>1) numbers are obtained for the whole range of possible tilt angles. These expressions almost overlap: It is shown that these analytical expressions describe very well the results of numerical calculations at any Peclet numbers except for a very narrow range of Pe close to unity. A method of calculation of the cut shape (variation of the tilt angle inside the cut) is discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021302/1-9]
Titre : Heat transfer in thin multilayered plates. Part I, A new approach Type de document : texte imprimé Auteurs : T. K. Papathanasiou, Auteur ; S. I. Markolefas, Auteur ; S. P. Filopoulos, Auteur Année de publication : 2011 Article en page(s) : pp. [021302/1-9] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat transfer Composite materials Multilayered plates First order lamination theory Index. décimale : 536 Chaleur. Thermodynamique Résumé : We present a new model for the determination of temperature distributions in thin plates consisting of many different layers. The method uses both continuous and discrete approaches. The derived set of equations is based on a continuous representation of heat transfer phenomena at the midplane of each layer, whereas it facilitates a discrete process for introducing ply to ply, through thickness, heat transfer. For the steady state case, the resulting equations are of the Helmholtz type. Methods of solutions for the resulting system are discussed, and comparisons with the first order lamination theory are presented in a benchmark example.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat transfer in thin multilayered plates. Part I, A new approach [texte imprimé] / T. K. Papathanasiou, Auteur ; S. I. Markolefas, Auteur ; S. P. Filopoulos, Auteur . - 2011 . - pp. [021302/1-9].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021302/1-9]
Mots-clés : Heat transfer Composite materials Multilayered plates First order lamination theory Index. décimale : 536 Chaleur. Thermodynamique Résumé : We present a new model for the determination of temperature distributions in thin plates consisting of many different layers. The method uses both continuous and discrete approaches. The derived set of equations is based on a continuous representation of heat transfer phenomena at the midplane of each layer, whereas it facilitates a discrete process for introducing ply to ply, through thickness, heat transfer. For the steady state case, the resulting equations are of the Helmholtz type. Methods of solutions for the resulting system are discussed, and comparisons with the first order lamination theory are presented in a benchmark example.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021303/1-7]
Titre : Heat transfer in thin multilayered plates.Part II; Applications to the composite patch repair technique Type de document : texte imprimé Auteurs : T. K. Papathanasiou, Auteur ; S. I. Markolefas, Auteur ; S. P. Filopoulos, Auteur Année de publication : 2011 Article en page(s) : pp. [021303/1-7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat transfer Extended surfaces Composite patch repair Multilayered plates Index. décimale : 536 Chaleur. Thermodynamique Résumé : This second part of our contribution entitled, “Heat Transfer in Thin Multilayered Plates,” refers to the modeling of an advanced repair technique, known as the composite patch repair (CPR). Thermal analysis of this particular application is highly complicated due to the geometry of the domains and the fact that many different materials participate in the implementation. In this paper, we take advantage of the fact that both the composite patch and the damaged plate to be repaired are of very small thickness. In that way, the whole domain may be treated as a thin multilayer area of extended surface. These properties make the thermal analysis of CPR an ideal field for using the method presented in the previous part of our analysis.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat transfer in thin multilayered plates.Part II; Applications to the composite patch repair technique [texte imprimé] / T. K. Papathanasiou, Auteur ; S. I. Markolefas, Auteur ; S. P. Filopoulos, Auteur . - 2011 . - pp. [021303/1-7].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021303/1-7]
Mots-clés : Heat transfer Extended surfaces Composite patch repair Multilayered plates Index. décimale : 536 Chaleur. Thermodynamique Résumé : This second part of our contribution entitled, “Heat Transfer in Thin Multilayered Plates,” refers to the modeling of an advanced repair technique, known as the composite patch repair (CPR). Thermal analysis of this particular application is highly complicated due to the geometry of the domains and the fact that many different materials participate in the implementation. In this paper, we take advantage of the fact that both the composite patch and the damaged plate to be repaired are of very small thickness. In that way, the whole domain may be treated as a thin multilayer area of extended surface. These properties make the thermal analysis of CPR an ideal field for using the method presented in the previous part of our analysis.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021304/1-6]
Titre : Boundary control of temperature distribution in a rectangular functionally graded material plate Type de document : texte imprimé Auteurs : Hossein Rastgoftar, Auteur ; Mohammad Eghtesad, Auteur ; Alireza Khayatian, Auteur Année de publication : 2011 Article en page(s) : pp. [021304/1-6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat conduction Lyapunov methods Numerical analysis Partial differential equations Specific heat Temperature distribution Thermal conductivity Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, an analytical method and a partial differential equation based solution to control temperature distribution for functionally graded (FG) plates is introduced. For the rectangular FG plate under consideration, it is assumed that the material properties such as thermal conductivity, density, and specific heat capacity vary in the width direction, and the governing heat conduction equation of the plate is a second-order partial differential equation. Using Lyapunov's theorem, it is shown that by applying controlled heat flux through the boundary of the domain, the temperature distribution of the plate will approach a desired steady-state distribution. Numerical simulation is provided to verify the effectiveness of the proposed method such that by applying the boundary transient heat flux, in-domain distributed temperature converges to its desired steady-state temperature.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Boundary control of temperature distribution in a rectangular functionally graded material plate [texte imprimé] / Hossein Rastgoftar, Auteur ; Mohammad Eghtesad, Auteur ; Alireza Khayatian, Auteur . - 2011 . - pp. [021304/1-6].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021304/1-6]
Mots-clés : Heat conduction Lyapunov methods Numerical analysis Partial differential equations Specific heat Temperature distribution Thermal conductivity Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, an analytical method and a partial differential equation based solution to control temperature distribution for functionally graded (FG) plates is introduced. For the rectangular FG plate under consideration, it is assumed that the material properties such as thermal conductivity, density, and specific heat capacity vary in the width direction, and the governing heat conduction equation of the plate is a second-order partial differential equation. Using Lyapunov's theorem, it is shown that by applying controlled heat flux through the boundary of the domain, the temperature distribution of the plate will approach a desired steady-state distribution. Numerical simulation is provided to verify the effectiveness of the proposed method such that by applying the boundary transient heat flux, in-domain distributed temperature converges to its desired steady-state temperature.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021501/1-15]
Titre : Dropwise condensation underneath chemically textured surfaces : simulation and experiments Type de document : texte imprimé Auteurs : Basant Singh Sikarwar, Auteur ; Nirmal Kumar Battoo, Auteur ; Sameer Khandekar, Auteur Année de publication : 2011 Article en page(s) : pp. [021501/1-15] Note générale : Physique Langues : Anglais (eng) Mots-clés : Dropwise condensation Chemical texturing Pendant droplets Modeling and simulation Imaging Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experimental observations of dropwise condensation of water vapor on a chemically textured surface of glass and its detailed computer simulation are presented. Experiments are focused on the pendant mode of dropwise condensation on the underside of horizontal and inclined glass substrates. Chemical texturing of glass is achieved by silanation using octyl-decyl-tri-chloro-silane (C18H37C13Si) in a chemical vapor deposition process. The mathematical model is built in such a way that it captures all the major physical processes taking place during condensation. These include growth due to direct condensation, droplet coalescence, sliding, fall-off, and renucleation of droplets. The effects arising from lyophobicity, namely, the contact angle variation and its hysteresis, inclination of the substrate, and saturation temperature at which the condensation is carried out, have been incorporated. The importance of higher order effects neglected in the simulation is discussed. The results of model simulation are compared with the experimental data. After validation, a parametric study is carried out for cases not covered by the experimental regime, i.e., various fluids, substrate inclination angle, saturation temperature, and contact angle hysteresis. Major conclusions arrived at in the study are the following: The area of droplet coverage decreases with an increase in both static contact angle of the droplet and substrate inclination. As the substrate inclination increases, the time instant of commencement of sliding of the droplet is advanced. The critical angle of inclination required for the inception of droplet sliding varies inversely with the droplet volume. For a given static contact angle, the fall-off time of the droplet from the substrate is a linear function of the saturation temperature. For a given fluid, the drop size distribution is well represented by a power law. Average heat transfer coefficient is satisfactorily predicted by the developed model.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Dropwise condensation underneath chemically textured surfaces : simulation and experiments [texte imprimé] / Basant Singh Sikarwar, Auteur ; Nirmal Kumar Battoo, Auteur ; Sameer Khandekar, Auteur . - 2011 . - pp. [021501/1-15].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021501/1-15]
Mots-clés : Dropwise condensation Chemical texturing Pendant droplets Modeling and simulation Imaging Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experimental observations of dropwise condensation of water vapor on a chemically textured surface of glass and its detailed computer simulation are presented. Experiments are focused on the pendant mode of dropwise condensation on the underside of horizontal and inclined glass substrates. Chemical texturing of glass is achieved by silanation using octyl-decyl-tri-chloro-silane (C18H37C13Si) in a chemical vapor deposition process. The mathematical model is built in such a way that it captures all the major physical processes taking place during condensation. These include growth due to direct condensation, droplet coalescence, sliding, fall-off, and renucleation of droplets. The effects arising from lyophobicity, namely, the contact angle variation and its hysteresis, inclination of the substrate, and saturation temperature at which the condensation is carried out, have been incorporated. The importance of higher order effects neglected in the simulation is discussed. The results of model simulation are compared with the experimental data. After validation, a parametric study is carried out for cases not covered by the experimental regime, i.e., various fluids, substrate inclination angle, saturation temperature, and contact angle hysteresis. Major conclusions arrived at in the study are the following: The area of droplet coverage decreases with an increase in both static contact angle of the droplet and substrate inclination. As the substrate inclination increases, the time instant of commencement of sliding of the droplet is advanced. The critical angle of inclination required for the inception of droplet sliding varies inversely with the droplet volume. For a given static contact angle, the fall-off time of the droplet from the substrate is a linear function of the saturation temperature. For a given fluid, the drop size distribution is well represented by a power law. Average heat transfer coefficient is satisfactorily predicted by the developed model.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021701/1-6]
Titre : Heat and mass transfer on the MHD fluid flow due to a porous rotating disk with hall current and variable properties Type de document : texte imprimé Auteurs : Mustafa Turkyilmazoglu, Auteur Année de publication : 2011 Article en page(s) : pp. [021701/1-6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Rotating disk Conducting fluid Variable properties Joule heating Shear stress Heat transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : The steady magnetohydrodynamics (MHD) laminar compressible flow of an electrically conducting fluid on a porous rotating disk is considered in the present paper. The governing equations of motion are reduced to a set of nonlinear differential equations by means of similarity transformations. The fluid properties are taken to be strong functions of temperature and Hall current that also readily accounts for the viscous dissipation and Joule heating terms. Employing a highly accurate spectral numerical integration scheme, the effects of viscosity, thermal conductivity, Hall current, magnetic field, suction/injection, viscous dissipation, and Joule heating on the considered flow are examined. The quantities of particular physical interest, such as the torque, the wall shear stresses, the vertical suction velocity, and the rate of heat transfer are calculated and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat and mass transfer on the MHD fluid flow due to a porous rotating disk with hall current and variable properties [texte imprimé] / Mustafa Turkyilmazoglu, Auteur . - 2011 . - pp. [021701/1-6].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021701/1-6]
Mots-clés : Rotating disk Conducting fluid Variable properties Joule heating Shear stress Heat transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : The steady magnetohydrodynamics (MHD) laminar compressible flow of an electrically conducting fluid on a porous rotating disk is considered in the present paper. The governing equations of motion are reduced to a set of nonlinear differential equations by means of similarity transformations. The fluid properties are taken to be strong functions of temperature and Hall current that also readily accounts for the viscous dissipation and Joule heating terms. Employing a highly accurate spectral numerical integration scheme, the effects of viscosity, thermal conductivity, Hall current, magnetic field, suction/injection, viscous dissipation, and Joule heating on the considered flow are examined. The quantities of particular physical interest, such as the torque, the wall shear stresses, the vertical suction velocity, and the rate of heat transfer are calculated and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021701/1-6]
Titre : Heat and mass transfer on the MHD fluid flow due to a porous rotating disk with hall current and variable properties Type de document : texte imprimé Auteurs : Mustafa Turkyilmazoglu, Auteur Année de publication : 2011 Article en page(s) : pp. [021701/1-6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Rotating disk Conducting fluid Variable properties Joule heating Shear stress Heat transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : The steady magnetohydrodynamics (MHD) laminar compressible flow of an electrically conducting fluid on a porous rotating disk is considered in the present paper. The governing equations of motion are reduced to a set of nonlinear differential equations by means of similarity transformations. The fluid properties are taken to be strong functions of temperature and Hall current that also readily accounts for the viscous dissipation and Joule heating terms. Employing a highly accurate spectral numerical integration scheme, the effects of viscosity, thermal conductivity, Hall current, magnetic field, suction/injection, viscous dissipation, and Joule heating on the considered flow are examined. The quantities of particular physical interest, such as the torque, the wall shear stresses, the vertical suction velocity, and the rate of heat transfer are calculated and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat and mass transfer on the MHD fluid flow due to a porous rotating disk with hall current and variable properties [texte imprimé] / Mustafa Turkyilmazoglu, Auteur . - 2011 . - pp. [021701/1-6].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021701/1-6]
Mots-clés : Rotating disk Conducting fluid Variable properties Joule heating Shear stress Heat transfer Index. décimale : 536 Chaleur. Thermodynamique Résumé : The steady magnetohydrodynamics (MHD) laminar compressible flow of an electrically conducting fluid on a porous rotating disk is considered in the present paper. The governing equations of motion are reduced to a set of nonlinear differential equations by means of similarity transformations. The fluid properties are taken to be strong functions of temperature and Hall current that also readily accounts for the viscous dissipation and Joule heating terms. Employing a highly accurate spectral numerical integration scheme, the effects of viscosity, thermal conductivity, Hall current, magnetic field, suction/injection, viscous dissipation, and Joule heating on the considered flow are examined. The quantities of particular physical interest, such as the torque, the wall shear stresses, the vertical suction velocity, and the rate of heat transfer are calculated and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021702/1-10]
Titre : Convective heat transfer on a rotating disk with transverse air crossflow Type de document : texte imprimé Auteurs : Benjamin Latour, Auteur ; Pascale Bouvier, Auteur ; Souad Harmand, Auteur Année de publication : 2011 Article en page(s) : pp. [021702/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Rotating fins Air crossflow Forced convection Local heat transfer Infrared thermography Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this study, the local convective heat transfer from a rotating disk with a transverse air crossflow was evaluated using an infrared thermographic experimental setup. Solving the inverse conduction heat transfer problem allows the local convective heat transfer coefficient to be identified. We used the specification function method along with spatio-temporal regularization to develop a model of local convective heat transfer in order to take lateral conduction and 2D geometry into account. This model was tested using rotational Reynolds numbers (based on the cylinder diameter and the peripheral speed) between 0 and 17,200 and air crossflow Reynolds numbers between 0 and 39,600. In this paper, the distribution of the local heat transfer on the disk allows us to observe the combined effect of the rotation and air crossflow on heat exchanges. This coupling is able to be taken into account in a correlation of mean Nusselt number relative to both Reynolds numbers.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Convective heat transfer on a rotating disk with transverse air crossflow [texte imprimé] / Benjamin Latour, Auteur ; Pascale Bouvier, Auteur ; Souad Harmand, Auteur . - 2011 . - pp. [021702/1-10].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021702/1-10]
Mots-clés : Rotating fins Air crossflow Forced convection Local heat transfer Infrared thermography Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this study, the local convective heat transfer from a rotating disk with a transverse air crossflow was evaluated using an infrared thermographic experimental setup. Solving the inverse conduction heat transfer problem allows the local convective heat transfer coefficient to be identified. We used the specification function method along with spatio-temporal regularization to develop a model of local convective heat transfer in order to take lateral conduction and 2D geometry into account. This model was tested using rotational Reynolds numbers (based on the cylinder diameter and the peripheral speed) between 0 and 17,200 and air crossflow Reynolds numbers between 0 and 39,600. In this paper, the distribution of the local heat transfer on the disk allows us to observe the combined effect of the rotation and air crossflow on heat exchanges. This coupling is able to be taken into account in a correlation of mean Nusselt number relative to both Reynolds numbers.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021703/1-7]
Titre : Bifurcated forced convective heat transfer of supercritical CO2 flow in plane symmetric sudden expansion duct Type de document : texte imprimé Auteurs : Bi-Li Deng, Auteur ; Xin-Rong Zhang, Auteur ; Hiroshi Yamaguchi, Auteur Année de publication : 2011 Article en page(s) : pp. [021703/1-7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Supercritical CO2 Sudden expansion Bifurcated flow Forced convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : This study presents a computational investigation of forced convection of supercritical CO2 flow in plane symmetric sudden expansion duct at an expansion ratio of 2 in flow asymmetric regime. Computations were conducted at various Reynolds numbers in flow asymmetric regime and low wall heat fluxes below 500 W/m2 to examine the Reynolds number and thermal effects on the flow and heat transfer of the bifurcated flow. General flow features and temperature distributions are presented. The transitional Reynolds numbers above, which a third recirculation region will appear at different wall heat flux are presented, and thus thermal effects on the flow stability are discussed. Reynolds number and thermal effects on distributions of wall skin friction, pressure coefficient, and Nusselt number are presented and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Bifurcated forced convective heat transfer of supercritical CO2 flow in plane symmetric sudden expansion duct [texte imprimé] / Bi-Li Deng, Auteur ; Xin-Rong Zhang, Auteur ; Hiroshi Yamaguchi, Auteur . - 2011 . - pp. [021703/1-7].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021703/1-7]
Mots-clés : Supercritical CO2 Sudden expansion Bifurcated flow Forced convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : This study presents a computational investigation of forced convection of supercritical CO2 flow in plane symmetric sudden expansion duct at an expansion ratio of 2 in flow asymmetric regime. Computations were conducted at various Reynolds numbers in flow asymmetric regime and low wall heat fluxes below 500 W/m2 to examine the Reynolds number and thermal effects on the flow and heat transfer of the bifurcated flow. General flow features and temperature distributions are presented. The transitional Reynolds numbers above, which a third recirculation region will appear at different wall heat flux are presented, and thus thermal effects on the flow stability are discussed. Reynolds number and thermal effects on distributions of wall skin friction, pressure coefficient, and Nusselt number are presented and discussed.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021801/1-10]
Titre : Cost and entropy generation minimization of a cross-flow plate fin heat exchanger using multi-objective genetic algorithm Type de document : texte imprimé Auteurs : Pouria Ahmadi, Auteur ; Hassan Hajabdollahi, Auteur ; Ibrahim Dincer, Auteur Année de publication : 2011 Article en page(s) : pp. [021801/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat exchanger Heat transfer Number of generation units Cost Optimization Genetic algorithm Index. décimale : 536 Chaleur. Thermodynamique Résumé : In the present work, a thermal modeling is conducted for optimal design of compact heat exchangers in order to minimize cost and entropy generation. In this regard, an epsilon−NTU method is applied for estimation of the heat exchanger pressure drop, as well as effectiveness. Fin pitch, fin height, fin offset length, cold stream flow length, no-flow length, and hot stream flow length are considered as six decision variables. Fast and elitist nondominated sorting genetic algorithm (i.e., nondominated sorting genetic algorithm II) is applied to minimize the entropy generation units and the total annual cost (sum of initial investment and operating and maintenance costs) simultaneously. The results for Pareto-optimal front clearly reveal the conflict between two objective functions, the number of entropy generation units and the total annual cost. It reveals that any geometrical changes, which decrease the number of entropy generation units, lead to an increase in the total annual cost and vice versa. Moreover, for prediction of the optimal design of the plate fin heat exchanger, an equation for the number of entropy generation units versus the total annual cost is derived for the Pareto curve. In addition, optimization of heat exchangers based on considering exergy destruction revealed that irreversibilities, such as pressure drop and high temperature difference between cold and hot streams, play a key issue in exergy destruction. Thus, more efficient heat exchanger leads to have a heat exchanger with higher total cost rate. Finally, the sensitivity analysis of change in the optimum number of entropy generation units and the total annual cost with change in the decision variables of the plate fin heat exchanger is also performed, and the results are reported.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Cost and entropy generation minimization of a cross-flow plate fin heat exchanger using multi-objective genetic algorithm [texte imprimé] / Pouria Ahmadi, Auteur ; Hassan Hajabdollahi, Auteur ; Ibrahim Dincer, Auteur . - 2011 . - pp. [021801/1-10].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021801/1-10]
Mots-clés : Heat exchanger Heat transfer Number of generation units Cost Optimization Genetic algorithm Index. décimale : 536 Chaleur. Thermodynamique Résumé : In the present work, a thermal modeling is conducted for optimal design of compact heat exchangers in order to minimize cost and entropy generation. In this regard, an epsilon−NTU method is applied for estimation of the heat exchanger pressure drop, as well as effectiveness. Fin pitch, fin height, fin offset length, cold stream flow length, no-flow length, and hot stream flow length are considered as six decision variables. Fast and elitist nondominated sorting genetic algorithm (i.e., nondominated sorting genetic algorithm II) is applied to minimize the entropy generation units and the total annual cost (sum of initial investment and operating and maintenance costs) simultaneously. The results for Pareto-optimal front clearly reveal the conflict between two objective functions, the number of entropy generation units and the total annual cost. It reveals that any geometrical changes, which decrease the number of entropy generation units, lead to an increase in the total annual cost and vice versa. Moreover, for prediction of the optimal design of the plate fin heat exchanger, an equation for the number of entropy generation units versus the total annual cost is derived for the Pareto curve. In addition, optimization of heat exchangers based on considering exergy destruction revealed that irreversibilities, such as pressure drop and high temperature difference between cold and hot streams, play a key issue in exergy destruction. Thus, more efficient heat exchanger leads to have a heat exchanger with higher total cost rate. Finally, the sensitivity analysis of change in the optimum number of entropy generation units and the total annual cost with change in the decision variables of the plate fin heat exchanger is also performed, and the results are reported.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021901/1-11]
Titre : The physical mechanism of heat transfer augmentation in stagnating flows subject to freestream turbulence Type de document : texte imprimé Auteurs : Andrew R. Gifford, Auteur ; Thomas E. Diller, Auteur ; Pavlos P. Vlachos, Auteur Année de publication : 2011 Article en page(s) : pp. [021901/1-11] Note générale : Physique Langues : Anglais (eng) Mots-clés : Coherent structures Digital particle image velocimetry Heat flux sensor Heat transfer augmentation Hiemenz flow Mechanistic model Turbulence Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experiments have been performed in a water tunnel facility to examine the physical mechanism of heat transfer augmentation by freestream turbulence in classical Hiemenz flow. A unique experimental approach to studying the problem is developed and demonstrated herein. Time-resolved digital particle image velocimetry (TRDPIV) and a new variety of thin-film heat flux sensor called the heat flux array (HFA) are used simultaneously to measure the spatiotemporal influence of coherent structures on the heat transfer coefficient as they approach and interact with the stagnation surface. Laminar flow and heat transfer at low levels of freestream turbulence ([overline Tu[sub x]]=0.5–1.0%) are examined to provide baseline flow characteristics and heat transfer coefficients. Similar experiments using a turbulence grid are performed to examine the effects of turbulence with mean streamwise turbulence intensity of [overline Tu[sub x]]=5.0% and an integral length scale of [overline Lambda[sub x]]=3.25 cm. At a Reynolds number of [overline Re[sub D]]=[overline U[sub [infinity]]]D/upsilon=21,000, an average increase in the mean heat transfer coefficient of 64% above the laminar level was observed. Experimental studies confirm that coherent structures play a dominant role in the augmentation of heat transfer in the stagnation region. Calculation and examination of the transient physical properties for coherent structures (i.e., circulation, area averaged vorticity, integral length scale, and proximity to the surface) shows that freestream turbulence is stretched and vorticity is amplified as it is convected toward the stagnation surface. The resulting stagnation flow is dominated by dynamic, counter-rotating vortex pairs. Heat transfer augmentation occurs when the rotational motion of coherent structures sweeps cooler freestream fluid into the laminar momentum and thermal boundary layers into close proximity of the heated stagnation surface. Evidence in support of this mechanism is provided through validation of a new mechanistic model, which incorporates the transient physical properties of tracked coherent structures. The model performs well in capturing the essential dynamics of the interaction and in the prediction of the experimentally measured transient and time-averaged turbulent heat transfer coefficients.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] The physical mechanism of heat transfer augmentation in stagnating flows subject to freestream turbulence [texte imprimé] / Andrew R. Gifford, Auteur ; Thomas E. Diller, Auteur ; Pavlos P. Vlachos, Auteur . - 2011 . - pp. [021901/1-11].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021901/1-11]
Mots-clés : Coherent structures Digital particle image velocimetry Heat flux sensor Heat transfer augmentation Hiemenz flow Mechanistic model Turbulence Index. décimale : 536 Chaleur. Thermodynamique Résumé : Experiments have been performed in a water tunnel facility to examine the physical mechanism of heat transfer augmentation by freestream turbulence in classical Hiemenz flow. A unique experimental approach to studying the problem is developed and demonstrated herein. Time-resolved digital particle image velocimetry (TRDPIV) and a new variety of thin-film heat flux sensor called the heat flux array (HFA) are used simultaneously to measure the spatiotemporal influence of coherent structures on the heat transfer coefficient as they approach and interact with the stagnation surface. Laminar flow and heat transfer at low levels of freestream turbulence ([overline Tu[sub x]]=0.5–1.0%) are examined to provide baseline flow characteristics and heat transfer coefficients. Similar experiments using a turbulence grid are performed to examine the effects of turbulence with mean streamwise turbulence intensity of [overline Tu[sub x]]=5.0% and an integral length scale of [overline Lambda[sub x]]=3.25 cm. At a Reynolds number of [overline Re[sub D]]=[overline U[sub [infinity]]]D/upsilon=21,000, an average increase in the mean heat transfer coefficient of 64% above the laminar level was observed. Experimental studies confirm that coherent structures play a dominant role in the augmentation of heat transfer in the stagnation region. Calculation and examination of the transient physical properties for coherent structures (i.e., circulation, area averaged vorticity, integral length scale, and proximity to the surface) shows that freestream turbulence is stretched and vorticity is amplified as it is convected toward the stagnation surface. The resulting stagnation flow is dominated by dynamic, counter-rotating vortex pairs. Heat transfer augmentation occurs when the rotational motion of coherent structures sweeps cooler freestream fluid into the laminar momentum and thermal boundary layers into close proximity of the heated stagnation surface. Evidence in support of this mechanism is provided through validation of a new mechanistic model, which incorporates the transient physical properties of tracked coherent structures. The model performs well in capturing the essential dynamics of the interaction and in the prediction of the experimentally measured transient and time-averaged turbulent heat transfer coefficients.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021902/1-6]
Titre : Heat transfer enhancement of MHD flow by conducting strips on the insulating wall Type de document : texte imprimé Auteurs : Hulin Huang, Auteur ; Bo Li, Auteur Année de publication : 2011 Article en page(s) : pp. [021902/1-6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat transfer enhancement Nonuniform electrical conductiv free surface Magnetohydrodynamic MHD flow Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to the magnetohydrodynamic (MHD) effect, which degrades heat transfer coefficients by pulsation suppression of the external magnetic field, on the electrically conducting flow, the wall with nonuniform electrical conductivity is employed in a MHD-flow system for heat transfer enhancement. The nonuniform electrical conductivity distribution of the channel wall could create alternate Lorentz forces along the spanwise direction, which can effectively produce flow disturbance, promote mixture, reduce the thickness of the boundary layer, and enhance heat transfer. So, the heat transfer performances enhanced by some conducting strips aligned with the mean flow direction on the insulating wall for free surface MHD flow are simulated numerically in this paper. The flow behaviors, heat transfer coefficients, friction factors, and pressure drops are presented under different Hartmann numbers. Results show that in the range of Hartmann numbers 30<=Ha<=100, the wall with nonuniform conductivity can achieve heat transfer enhancements (Nu/Nu0) of about 1.2–1.6 relative to the insulating wall, with negligible friction augmentation. This research indicates that the modules with three or five conducting strips can obtain better enhancement effect in our research. Particularly, the heat transfer augmentation increases monotonically with increasing Hartmann numbers. Therefore, the enhancement purpose for high Hartmann number MHD flow is marked, which may remedy the depressing heat transfer coefficients by the MHD effect.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat transfer enhancement of MHD flow by conducting strips on the insulating wall [texte imprimé] / Hulin Huang, Auteur ; Bo Li, Auteur . - 2011 . - pp. [021902/1-6].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [021902/1-6]
Mots-clés : Heat transfer enhancement Nonuniform electrical conductiv free surface Magnetohydrodynamic MHD flow Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to the magnetohydrodynamic (MHD) effect, which degrades heat transfer coefficients by pulsation suppression of the external magnetic field, on the electrically conducting flow, the wall with nonuniform electrical conductivity is employed in a MHD-flow system for heat transfer enhancement. The nonuniform electrical conductivity distribution of the channel wall could create alternate Lorentz forces along the spanwise direction, which can effectively produce flow disturbance, promote mixture, reduce the thickness of the boundary layer, and enhance heat transfer. So, the heat transfer performances enhanced by some conducting strips aligned with the mean flow direction on the insulating wall for free surface MHD flow are simulated numerically in this paper. The flow behaviors, heat transfer coefficients, friction factors, and pressure drops are presented under different Hartmann numbers. Results show that in the range of Hartmann numbers 30<=Ha<=100, the wall with nonuniform conductivity can achieve heat transfer enhancements (Nu/Nu0) of about 1.2–1.6 relative to the insulating wall, with negligible friction augmentation. This research indicates that the modules with three or five conducting strips can obtain better enhancement effect in our research. Particularly, the heat transfer augmentation increases monotonically with increasing Hartmann numbers. Therefore, the enhancement purpose for high Hartmann number MHD flow is marked, which may remedy the depressing heat transfer coefficients by the MHD effect.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022401/1-15]
Titre : Modeling of heat transfer in microchannel gas flow Type de document : texte imprimé Auteurs : Tomasz Lewandowski, Auteur ; Tomasz Ochrymiuk, Auteur ; Justyna Czerwinska, Auteur Année de publication : 2011 Article en page(s) : pp. [022401/1-15] Note générale : Physique Langues : Anglais (eng) Mots-clés : Microchannel gas flow Heat transfer Slip regime Turbomachinery Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to the existence of a velocity slip and temperature jump on the solid walls, the heat transfer in microchannels significantly differs from the one in the macroscale. In our research, we have focused on the pressure driven gas flows in a simple finite microchannel geometry, with an entrance and an outlet, for low Reynolds (Re<200) and low Knudsen (Kn<0.01) numbers. For such a regime, the slip induced phenomena are strongly connected with the viscous effects. As a result, heat transfer is also significantly altered. For the optimization of flow conditions, we have investigated various temperature gradient configurations, additionally changing Reynolds and Knudsen numbers. The entrance effects, slip flow, and temperature jump lead to complex relations between flow behavior and heat transfer. We have shown that slip effects are generally insignificant for flow behavior. However, two configuration setups (hot wall cold gas and cold wall hot gas) are affected by slip in distinguishably different ways. For the first one, which concerns turbomachinery, the mass flow rate can increase by about 1% in relation to the no-slip case, depending on the wall-gas temperature difference. Heat transfer is more significantly altered. The Nusselt number between slip and no-slip cases at the outlet of the microchannel is increased by about 10%.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Modeling of heat transfer in microchannel gas flow [texte imprimé] / Tomasz Lewandowski, Auteur ; Tomasz Ochrymiuk, Auteur ; Justyna Czerwinska, Auteur . - 2011 . - pp. [022401/1-15].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022401/1-15]
Mots-clés : Microchannel gas flow Heat transfer Slip regime Turbomachinery Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to the existence of a velocity slip and temperature jump on the solid walls, the heat transfer in microchannels significantly differs from the one in the macroscale. In our research, we have focused on the pressure driven gas flows in a simple finite microchannel geometry, with an entrance and an outlet, for low Reynolds (Re<200) and low Knudsen (Kn<0.01) numbers. For such a regime, the slip induced phenomena are strongly connected with the viscous effects. As a result, heat transfer is also significantly altered. For the optimization of flow conditions, we have investigated various temperature gradient configurations, additionally changing Reynolds and Knudsen numbers. The entrance effects, slip flow, and temperature jump lead to complex relations between flow behavior and heat transfer. We have shown that slip effects are generally insignificant for flow behavior. However, two configuration setups (hot wall cold gas and cold wall hot gas) are affected by slip in distinguishably different ways. For the first one, which concerns turbomachinery, the mass flow rate can increase by about 1% in relation to the no-slip case, depending on the wall-gas temperature difference. Heat transfer is more significantly altered. The Nusselt number between slip and no-slip cases at the outlet of the microchannel is increased by about 10%.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022402/1-7]
Titre : Phonon boundary effects and thermal conductivity of rough concentric nanowires Type de document : texte imprimé Auteurs : F. X. Alvarez, Auteur ; D. Jou, Auteur ; A. Sellitto, Auteur Année de publication : 2011 Article en page(s) : pp. [022402/1-7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Phonon hydrodynamic Nanowires Nanosystems Thermal conductivity Ballistic transport Heat transport Index. décimale : 536 Chaleur. Thermodynamique Résumé : By using a phonon hydrodynamics model for heat flow complemented with boundary conditions for smooth or rough boundaries, we study the influence of boundary conditions on the longitudinal thermal conductivity for several kinds of nanowires (single, tubular, and core-shell). The effects of the boundaries are seen to be extremely important.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Phonon boundary effects and thermal conductivity of rough concentric nanowires [texte imprimé] / F. X. Alvarez, Auteur ; D. Jou, Auteur ; A. Sellitto, Auteur . - 2011 . - pp. [022402/1-7].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022402/1-7]
Mots-clés : Phonon hydrodynamic Nanowires Nanosystems Thermal conductivity Ballistic transport Heat transport Index. décimale : 536 Chaleur. Thermodynamique Résumé : By using a phonon hydrodynamics model for heat flow complemented with boundary conditions for smooth or rough boundaries, we study the influence of boundary conditions on the longitudinal thermal conductivity for several kinds of nanowires (single, tubular, and core-shell). The effects of the boundaries are seen to be extremely important.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022403/1-7]
Titre : Thermal conductivity measurement of graphene exfoliated on silicon dioxide Type de document : texte imprimé Auteurs : Jae Hun Seol, Auteur ; Arden L. Moore, Auteur ; Li Shi, Auteur Année de publication : 2011 Article en page(s) : pp. [022403/1-7] Note générale : Physique Langues : Anglais (eng) Mots-clés : Thermal conductivity Supported graphene Phonon transport Measurement Index. décimale : 536 Chaleur. Thermodynamique Résumé : We have developed a nanofabricated resistance thermometer device to measure the thermal conductivity of graphene monolayers exfoliated onto silicon dioxide. The measurement results show that the thermal conductivity of the supported graphene is approximately 600 W/m K at room temperature. While this value is lower than the reported basal plane values for graphite and suspended graphene because of phonon leakage across the graphene-support interface, it is still considerably higher than the values for common thin film electronic materials. Here, we present a detailed discussion of the design and fabrication of the measurement device. Analytical and numerical heat transfer solutions are developed to evaluate the accuracy and uncertainty of this method for thermal conductivity measurement of high-thermal conductivity ultrathin films.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Thermal conductivity measurement of graphene exfoliated on silicon dioxide [texte imprimé] / Jae Hun Seol, Auteur ; Arden L. Moore, Auteur ; Li Shi, Auteur . - 2011 . - pp. [022403/1-7].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022403/1-7]
Mots-clés : Thermal conductivity Supported graphene Phonon transport Measurement Index. décimale : 536 Chaleur. Thermodynamique Résumé : We have developed a nanofabricated resistance thermometer device to measure the thermal conductivity of graphene monolayers exfoliated onto silicon dioxide. The measurement results show that the thermal conductivity of the supported graphene is approximately 600 W/m K at room temperature. While this value is lower than the reported basal plane values for graphite and suspended graphene because of phonon leakage across the graphene-support interface, it is still considerably higher than the values for common thin film electronic materials. Here, we present a detailed discussion of the design and fabrication of the measurement device. Analytical and numerical heat transfer solutions are developed to evaluate the accuracy and uncertainty of this method for thermal conductivity measurement of high-thermal conductivity ultrathin films.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022404/1-9]
Titre : Numerical analysis of the time-dependent energy and momentum transfers in a rarefied gas between two parallel planes based on the linearized Boltzmann equation Type de document : texte imprimé Auteurs : Toshiyuki Doi, Auteur Année de publication : 2011 Article en page(s) : pp. [022404/1-9] Note générale : Physique Langues : Anglais (eng) Mots-clés : Boltzmann equation Rarefied gaz Microflow Oscillatory heating Index. décimale : 536 Chaleur. Thermodynamique Résumé : Periodic time-dependent behavior of a rarefied gas between two parallel planes caused by an oscillatory heating of one plane is numerically studied based on the linearized Boltzmann equation. Detailed numerical data of the energy transfer from the heated plane to the unheated plane and the forces of the gas acting on the boundaries are provided for a wide range of the gas rarefaction degree and the oscillation frequency. The flow is characterized by a coupling of heat conduction and sound waves caused by repetitive expansion and contraction of the gas. For a small gas rarefaction degree, the energy transfer is mainly conducted by sound waves, except for very low frequencies, and is strongly affected by the resonance of the waves. For a large gas rarefaction degree, the resonance effects become insignificant and the energy transferred to the unheated plane decreases nearly monotonically as the frequency increases. The force of the gas acting on the heated boundary shows a remarkable minimum with respect to the frequency even in the free molecular limit.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Numerical analysis of the time-dependent energy and momentum transfers in a rarefied gas between two parallel planes based on the linearized Boltzmann equation [texte imprimé] / Toshiyuki Doi, Auteur . - 2011 . - pp. [022404/1-9].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022404/1-9]
Mots-clés : Boltzmann equation Rarefied gaz Microflow Oscillatory heating Index. décimale : 536 Chaleur. Thermodynamique Résumé : Periodic time-dependent behavior of a rarefied gas between two parallel planes caused by an oscillatory heating of one plane is numerically studied based on the linearized Boltzmann equation. Detailed numerical data of the energy transfer from the heated plane to the unheated plane and the forces of the gas acting on the boundaries are provided for a wide range of the gas rarefaction degree and the oscillation frequency. The flow is characterized by a coupling of heat conduction and sound waves caused by repetitive expansion and contraction of the gas. For a small gas rarefaction degree, the energy transfer is mainly conducted by sound waves, except for very low frequencies, and is strongly affected by the resonance of the waves. For a large gas rarefaction degree, the resonance effects become insignificant and the energy transferred to the unheated plane decreases nearly monotonically as the frequency increases. The force of the gas acting on the heated boundary shows a remarkable minimum with respect to the frequency even in the free molecular limit.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022501/1-5]
Titre : Modeling of free convection heat transfer to a supercritical fluid in a square enclosure by the lattice Boltzmann method Type de document : texte imprimé Auteurs : Mostafa Varmazyar, Auteur ; Majid Bazargan, Auteur Année de publication : 2011 Article en page(s) : pp. [022501/1-5] Note générale : Physique Langues : Anglais (eng) Mots-clés : Lattice Boltzmann method Energy equation Supercritical fluid flow Cavity enclosure Free convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : During the last decade, a number of numerical computations based on the finite volume approach have been reported, studying various aspects of heat transfer near the critical point. In this paper, a lattice Boltzmann method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The lattice Boltzmann equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function, and is the basis of the LBM. For the mass and momentum equations, a LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, interparticle forces are taken into account for nonideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM-FVM (finite volume method) combination are found to be in excellent agreement with the FVM-FVM combination for the Navier–Stokes and heat transfer equations.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Modeling of free convection heat transfer to a supercritical fluid in a square enclosure by the lattice Boltzmann method [texte imprimé] / Mostafa Varmazyar, Auteur ; Majid Bazargan, Auteur . - 2011 . - pp. [022501/1-5].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022501/1-5]
Mots-clés : Lattice Boltzmann method Energy equation Supercritical fluid flow Cavity enclosure Free convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : During the last decade, a number of numerical computations based on the finite volume approach have been reported, studying various aspects of heat transfer near the critical point. In this paper, a lattice Boltzmann method (LBM) has been developed to simulate laminar free convection heat transfer to a supercritical fluid in a square enclosure. The LBM is an ideal mesoscopic approach to solve nonlinear macroscopic conservation equations due to its simplicity and capability of parallelization. The lattice Boltzmann equation (LBE) represents the minimal form of the Boltzmann kinetic equation. The LBE is a very elegant and simple equation, for a discrete density distribution function, and is the basis of the LBM. For the mass and momentum equations, a LBM is used while the heat equation is solved numerically by a finite volume scheme. In this study, interparticle forces are taken into account for nonideal gases in order to simulate the velocity profile more accurately. The laminar free convection cavity flow has been extensively used as a benchmark test to evaluate the accuracy of the numerical code. It is found that the numerical results of this study are in good agreement with the experimental and numerical results reported in the literature. The results of the LBM-FVM (finite volume method) combination are found to be in excellent agreement with the FVM-FVM combination for the Navier–Stokes and heat transfer equations.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022502/1-6]
Titre : MHD Mixed convection boundary layer flow toward a stagnation point on a vertical surface with induced magnetic field Type de document : texte imprimé Auteurs : F. M. Ali, Auteur ; R. Nazar, Auteur ; N. M. Arifin, Auteur Année de publication : 2011 Article en page(s) : pp. [022502/1-6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Boundary layer Dual solutions Induced magnetic field MHD Mixed convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, the steady magnetohydrodynamic (MHD) mixed convection stagnation point flow of an incompressible, viscous, and electrically conducting fluid over a vertical flat plate is investigated. The effect of induced magnetic field is taken into account. Numerical results are obtained using an implicit finite-difference scheme. Both assisting and opposing flows are considered. The results for skin friction, heat transfer, and induced magnetic field coefficients are obtained and discussed for various parameters. The velocity, temperature, and induced magnetic field profiles are also presented. For the case of the opposing flow, it is found that dual solutions exist for a certain range of the buoyancy parameter. Dual solutions are also obtained for the assisting flow.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] MHD Mixed convection boundary layer flow toward a stagnation point on a vertical surface with induced magnetic field [texte imprimé] / F. M. Ali, Auteur ; R. Nazar, Auteur ; N. M. Arifin, Auteur . - 2011 . - pp. [022502/1-6].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022502/1-6]
Mots-clés : Boundary layer Dual solutions Induced magnetic field MHD Mixed convection Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, the steady magnetohydrodynamic (MHD) mixed convection stagnation point flow of an incompressible, viscous, and electrically conducting fluid over a vertical flat plate is investigated. The effect of induced magnetic field is taken into account. Numerical results are obtained using an implicit finite-difference scheme. Both assisting and opposing flows are considered. The results for skin friction, heat transfer, and induced magnetic field coefficients are obtained and discussed for various parameters. The velocity, temperature, and induced magnetic field profiles are also presented. For the case of the opposing flow, it is found that dual solutions exist for a certain range of the buoyancy parameter. Dual solutions are also obtained for the assisting flow.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022503/1-10]
Titre : Mixed convective heat transfer past a heated square porous cylinder in a horizontal channel with varying channel height Type de document : texte imprimé Auteurs : Horng-Wen Wu, Auteur ; Ren-Hung Wang, Auteur Année de publication : 2011 Article en page(s) : pp. [022503/1-10] Note générale : Physique Langues : Anglais (eng) Mots-clés : Heat transfer Square porous cylinder Buoyancy Darcy number Channel-to-cylinder height ratio Index. décimale : 536 Chaleur. Thermodynamique Résumé : The laminar mixed convection flow across the porous square cylinder with the heated cylinder bottom at the axis in the channel has been carried out numerically in this paper using a semi-implicit projection finite element method. The governing equations with the Brinkman–Forcheimer-extended Darcy model for the region of square porous cylinder were solved. The parameter studies including Grashof number, Darcy number, and channel-to-cylinder height ratio on heat transfer performance have been explored in detail. The results indicate that the heat transfer is augmented as the Darcy number and channel-to-cylinder height ratio increase. The buoyancy effect on the local Nusselt number is clearer for B/H=0.1 than for B/H=0.3 and B/H=0.5.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Mixed convective heat transfer past a heated square porous cylinder in a horizontal channel with varying channel height [texte imprimé] / Horng-Wen Wu, Auteur ; Ren-Hung Wang, Auteur . - 2011 . - pp. [022503/1-10].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [022503/1-10]
Mots-clés : Heat transfer Square porous cylinder Buoyancy Darcy number Channel-to-cylinder height ratio Index. décimale : 536 Chaleur. Thermodynamique Résumé : The laminar mixed convection flow across the porous square cylinder with the heated cylinder bottom at the axis in the channel has been carried out numerically in this paper using a semi-implicit projection finite element method. The governing equations with the Brinkman–Forcheimer-extended Darcy model for the region of square porous cylinder were solved. The parameter studies including Grashof number, Darcy number, and channel-to-cylinder height ratio on heat transfer performance have been explored in detail. The results indicate that the heat transfer is augmented as the Darcy number and channel-to-cylinder height ratio increase. The buoyancy effect on the local Nusselt number is clearer for B/H=0.1 than for B/H=0.3 and B/H=0.5.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024501/1-4]
Titre : Enhanced specific heat of silica nanofluid Type de document : texte imprimé Auteurs : Donghyun Shin, Auteur ; Debjyoti Banerjee, Auteur Année de publication : 2011 Article en page(s) : pp. [024501/1-4] Note générale : Physique Langues : Anglais (eng) Mots-clés : Nanofluid Specific heat Nanoparticle Molten salt Lithium carbonate Potassium carbonate Solar energy Thermal energy storage Phase change material Index. décimale : 536 Chaleur. Thermodynamique Résumé : Silica nanoparticles (1% by weight) were dispersed in a eutectic of lithium carbonate and potassium carbonate (62:38 ratio) to obtain high temperature nanofluids. A differential scanning calorimeter instrument was used to measure the specific heat of the neat molten salt eutectic and after addition of nanoparticles. The specific heat of the nanofluid was enhanced by 19–24%. The measurement uncertainty for the specific heat values in the experiments is estimated to be in the range of 1–5%. These experimental data contradict earlier experimental results reported in the literature. (Notably, the stability of the nanofluid samples was not verified in these studies.) In the present study, the dispersion and stability of the nanoparticles were confirmed by using scanning electron microscopy (SEM). Percolation networks were observed in the SEM image of the nanofluid. Furthermore, no agglomeration of the nanoparticles was observed, as confirmed by transmission electron microscopy. The observed enhancements are suggested to be due to the high specific surface energies that are associated with the high surface area of the nanoparticles per unit volume (or per unit mass).
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Enhanced specific heat of silica nanofluid [texte imprimé] / Donghyun Shin, Auteur ; Debjyoti Banerjee, Auteur . - 2011 . - pp. [024501/1-4].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024501/1-4]
Mots-clés : Nanofluid Specific heat Nanoparticle Molten salt Lithium carbonate Potassium carbonate Solar energy Thermal energy storage Phase change material Index. décimale : 536 Chaleur. Thermodynamique Résumé : Silica nanoparticles (1% by weight) were dispersed in a eutectic of lithium carbonate and potassium carbonate (62:38 ratio) to obtain high temperature nanofluids. A differential scanning calorimeter instrument was used to measure the specific heat of the neat molten salt eutectic and after addition of nanoparticles. The specific heat of the nanofluid was enhanced by 19–24%. The measurement uncertainty for the specific heat values in the experiments is estimated to be in the range of 1–5%. These experimental data contradict earlier experimental results reported in the literature. (Notably, the stability of the nanofluid samples was not verified in these studies.) In the present study, the dispersion and stability of the nanoparticles were confirmed by using scanning electron microscopy (SEM). Percolation networks were observed in the SEM image of the nanofluid. Furthermore, no agglomeration of the nanoparticles was observed, as confirmed by transmission electron microscopy. The observed enhancements are suggested to be due to the high specific surface energies that are associated with the high surface area of the nanoparticles per unit volume (or per unit mass).
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024502/1-3]
Titre : Laminar heat and mass transfer in rotating cone-and-plate devices Type de document : texte imprimé Auteurs : I. V. Shevchuk, Auteur Année de publication : 2011 Article en page(s) : pp. [024502/1-3] Note générale : Physique Langues : Anglais (eng) Mots-clés : Cone-and-plateevice Rotating disk Heat mass transfer Efficiency Index. décimale : 536 Chaleur. Thermodynamique Résumé : The convective diffusion of feeding culture and the effect of fluid shear stress on endothelial cells are frequently investigated in cone-and-plate devices. Laminar fluid flow and heat and mass transfer in a cone-and-plate device, with cone apex touching the plate/disk, were simulated. The disk-to-cone gap made 1–5 deg. Transport equations were reduced to a system of self-similar ordinary differential equations solved numerically. Cases studied were a rotating cone and a stationary plate, and vice versa. The cone was isothermal, while the disk temperature followed a power-law radial distribution; boundary concentrations were constant. Prandtl and Schmidt numbers varied from 0.1 to 800. Temperature/diffusion profiles in the gap and Nusselt and Sherwood numbers exhibit different regimes of heat/mass transfer, depending on the disk surface temperature distribution.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Laminar heat and mass transfer in rotating cone-and-plate devices [texte imprimé] / I. V. Shevchuk, Auteur . - 2011 . - pp. [024502/1-3].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024502/1-3]
Mots-clés : Cone-and-plateevice Rotating disk Heat mass transfer Efficiency Index. décimale : 536 Chaleur. Thermodynamique Résumé : The convective diffusion of feeding culture and the effect of fluid shear stress on endothelial cells are frequently investigated in cone-and-plate devices. Laminar fluid flow and heat and mass transfer in a cone-and-plate device, with cone apex touching the plate/disk, were simulated. The disk-to-cone gap made 1–5 deg. Transport equations were reduced to a system of self-similar ordinary differential equations solved numerically. Cases studied were a rotating cone and a stationary plate, and vice versa. The cone was isothermal, while the disk temperature followed a power-law radial distribution; boundary concentrations were constant. Prandtl and Schmidt numbers varied from 0.1 to 800. Temperature/diffusion profiles in the gap and Nusselt and Sherwood numbers exhibit different regimes of heat/mass transfer, depending on the disk surface temperature distribution.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024503/1-5]
Titre : Analytical solution for thermally fully developed combined electroosmotic and pressure-driven flows in narrow confinements with thick electrical double layers Type de document : texte imprimé Auteurs : Ranabir Dey, Auteur ; Debapriya Chakraborty, Auteur ; Suman Chakraborty, Auteur Année de publication : 2011 Article en page(s) : pp. [024503/1-5] Note générale : Physique Langues : Anglais (eng) Mots-clés : Thermally fully developed Narrow confinements Thick electric double layer Viscous dissipation Joule heating Nusselt number Index. décimale : 536 Chaleur. Thermodynamique Résumé : In the present paper, closed form solutions for the Nusselt number are obtained for hydrodynamically and thermally fully developed combined electroosmotic and pressure-driven flows in narrow confinements for the constant wall heat flux boundary condition. Overcoming the constraints of the standard models that are valid only within thin electrical double layer (EDL) limits, the effects of thick electric double layers are accounted for as a distinctive feature of this model. Along with Joule heating, viscous dissipation effects, which are particularly important for ultrathin channel dimensions (typically conforming to the cases of thick EDLs), are taken into account. The results are presented in terms of appropriate nondimensional parameters depicting the relative EDL thickness with respect to the channel height, as well as relative strengths of Joule heating and viscous dissipation effects.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Analytical solution for thermally fully developed combined electroosmotic and pressure-driven flows in narrow confinements with thick electrical double layers [texte imprimé] / Ranabir Dey, Auteur ; Debapriya Chakraborty, Auteur ; Suman Chakraborty, Auteur . - 2011 . - pp. [024503/1-5].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [024503/1-5]
Mots-clés : Thermally fully developed Narrow confinements Thick electric double layer Viscous dissipation Joule heating Nusselt number Index. décimale : 536 Chaleur. Thermodynamique Résumé : In the present paper, closed form solutions for the Nusselt number are obtained for hydrodynamically and thermally fully developed combined electroosmotic and pressure-driven flows in narrow confinements for the constant wall heat flux boundary condition. Overcoming the constraints of the standard models that are valid only within thin electrical double layer (EDL) limits, the effects of thick electric double layers are accounted for as a distinctive feature of this model. Along with Joule heating, viscous dissipation effects, which are particularly important for ultrathin channel dimensions (typically conforming to the cases of thick EDLs), are taken into account. The results are presented in terms of appropriate nondimensional parameters depicting the relative EDL thickness with respect to the channel height, as well as relative strengths of Joule heating and viscous dissipation effects.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [031001/1-4]
Titre : Structure controlled synthesis of vertically aligned carbon nanotubes using thermal chemical vapor deposition process Type de document : texte imprimé Auteurs : Myung Gwan Hahm, Auteur ; Young-Kyun Kwon, Auteur ; Ahmed Busnaina, Auteur Année de publication : 2011 Article en page(s) : pp. [031001/1-4] Note générale : Physique Langues : Anglais (eng) Mots-clés : Carbon nanotubes Chemical vapour deposition Nanotechnology Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to their unique one-dimensional nanostructure along with excellent mechanical, electrical, and optical properties, carbon nanotubes (CNTs) become a promising material for diverse nanotechnology applications. However, large-scale and structure controlled synthesis of CNTs still have many difficulties due to the lack of understanding of the fundamental growth mechanism of CNTs, as well as the difficulty of controlling atomic-scale physical and chemical reactions during the nanotube growth process. Especially, controlling the number of graphene wall, diameter, and chirality of CNTs are the most important issues that need to be solved to harness the full potential of CNTs. Here we report the large-scale selective synthesis of vertically aligned single walled carbon nanotubes (SWNTs) and double walled carbon nanotubes (DWNTs) by controlling the size of catalyst nanoparticles in the highly effective oxygen assisted thermal chemical vapor deposition (CVD) process. We also demonstrate a simple but powerful strategy for synthesizing ultrahigh density and diameter selected vertically aligned SWNTs through the precise control of carbon flow during a thermal CVD process.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Structure controlled synthesis of vertically aligned carbon nanotubes using thermal chemical vapor deposition process [texte imprimé] / Myung Gwan Hahm, Auteur ; Young-Kyun Kwon, Auteur ; Ahmed Busnaina, Auteur . - 2011 . - pp. [031001/1-4].
Physique
Langues : Anglais (eng)
in Journal of heat transfer > Vol. 133 N° 2 (Fevrier 2011) . - pp. [031001/1-4]
Mots-clés : Carbon nanotubes Chemical vapour deposition Nanotechnology Index. décimale : 536 Chaleur. Thermodynamique Résumé : Due to their unique one-dimensional nanostructure along with excellent mechanical, electrical, and optical properties, carbon nanotubes (CNTs) become a promising material for diverse nanotechnology applications. However, large-scale and structure controlled synthesis of CNTs still have many difficulties due to the lack of understanding of the fundamental growth mechanism of CNTs, as well as the difficulty of controlling atomic-scale physical and chemical reactions during the nanotube growth process. Especially, controlling the number of graphene wall, diameter, and chirality of CNTs are the most important issues that need to be solved to harness the full potential of CNTs. Here we report the large-scale selective synthesis of vertically aligned single walled carbon nanotubes (SWNTs) and double walled carbon nanotubes (DWNTs) by controlling the size of catalyst nanoparticles in the highly effective oxygen assisted thermal chemical vapor deposition (CVD) process. We also demonstrate a simple but powerful strategy for synthesizing ultrahigh density and diameter selected vertically aligned SWNTs through the precise control of carbon flow during a thermal CVD process.
DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]
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