Documents disponibles écrits par cet auteur

An experimental comparison of four magnetocaloric regenerators using three different materials / U. Legait in International journal of refrigeration, Vol. 37 N° 1 (Janvier 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 147–155 Titre : An experimental comparison of four magnetocaloric regenerators using three different materials Titre original : Une comparaison expérimentale de quatre régénérateurs magnétocaloriques utilisant trois matériaux différents Type de document : texte imprimé Auteurs : U. Legait, Auteur ; F. Guillou, Auteur ; A. Kedous-Lebouc, Auteur Année de publication : 2014 Article en page(s) : pp. 147–155 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Magnetic  refrigeration;  magnetocaloric  regenerator;  physical  properties;  gadolinium;  LaFeSiCo;  PrSrMnO Résumé : To optimize the performance of an active magnetic regenerative system (AMR), it is important to understand the heat transfer phenomena taking place in the regenerator and the impact of the intrinsic properties of the magnetocaloric material. With this aim in mind, four regenerators involving three different materials (Pr0.65Sr0.35MnO3, La(FeCo)13-xSix, and gadolinium) have been prepared and tested using a permanent magnet based device. This set-up allows studying the performance of different types of regenerators over a wide range of fluidic and magnetic operating conditions. However, since no thermal exchanger is used, this device provides only non-load temperature spans. First, this work deals with an analysis of the performance of the regenerators as a function of their utilization ratio (i.e. working conditions such as the mass flow rate and frequency). Then, an attempt is made to correlate the performance of each regenerator with the physical properties of these different materials. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001709 [article] An experimental comparison of four magnetocaloric regenerators using three different materials = Une comparaison expérimentale de quatre régénérateurs magnétocaloriques utilisant trois matériaux différents [texte imprimé] / U. Legait, Auteur ; F. Guillou, Auteur ; A. Kedous-Lebouc, Auteur . - 2014 . - pp. 147–155. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 147–155 Mots-clés : Magnetic  refrigeration;  magnetocaloric  regenerator;  physical  properties;  gadolinium;  LaFeSiCo;  PrSrMnO Résumé : To optimize the performance of an active magnetic regenerative system (AMR), it is important to understand the heat transfer phenomena taking place in the regenerator and the impact of the intrinsic properties of the magnetocaloric material. With this aim in mind, four regenerators involving three different materials (Pr0.65Sr0.35MnO3, La(FeCo)13-xSix, and gadolinium) have been prepared and tested using a permanent magnet based device. This set-up allows studying the performance of different types of regenerators over a wide range of fluidic and magnetic operating conditions. However, since no thermal exchanger is used, this device provides only non-load temperature spans. First, this work deals with an analysis of the performance of the regenerators as a function of their utilization ratio (i.e. working conditions such as the mass flow rate and frequency). Then, an attempt is made to correlate the performance of each regenerator with the physical properties of these different materials. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001709

Design of a new magnetic refrigeration field source running with rotating bar-shaped magnets / H. R. E. H. Bouchekara in International journal of refrigeration, Vol. 35 N° 1 (Janvier 2012) 

Public ISBD [article]  in International journal of refrigeration > Vol. 35 N° 1 (Janvier 2012) . - pp. 115–121 Titre : Design of a new magnetic refrigeration field source running with rotating bar-shaped magnets Titre original : Conception d'une nouvelle source de champ pour les systèmes frigorifiques magnétiques constitués d'aimants tournants en forme de barres Type de document : texte imprimé Auteurs : H. R. E. H. Bouchekara, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur Année de publication : 2012 Article en page(s) : pp. 115–121 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Magnetic  refrigerator  Magnet  Design  Magnetic  field Résumé : Magnetic refrigeration (MR) based on the magnetocaloric effect (MCE) is a prime candidate for the next generation of cooling systems. The essential components of magnetic refrigeration are the magnetic field generator and the magnetocaloric material. Although, several permanent magnet systems (magnetic field sources) for MR have been developed, recent development in magnetic refrigeration technology has encouraged researchers all over the world to think about new and original systems. This paper aims to describe a new and original magnetic refrigeration system based on a simple principle of magnetism called the Halbach effect. The proposed system is running with rotating bar-shaped magnets. This structure provides the desired varying magnetic field to the magnetocaloric material. Several configurations for the proposed systems have been investigated and presented in this paper. The design and modeling have been accomplished by using the finite elements method. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001952 [article] Design of a new magnetic refrigeration field source running with rotating bar-shaped magnets = Conception d'une nouvelle source de champ pour les systèmes frigorifiques magnétiques constitués d'aimants tournants en forme de barres [texte imprimé] / H. R. E. H. Bouchekara, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur . - 2012 . - pp. 115–121. Génie mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 35 N° 1 (Janvier 2012) . - pp. 115–121 Mots-clés : Magnetic  refrigerator  Magnet  Design  Magnetic  field Résumé : Magnetic refrigeration (MR) based on the magnetocaloric effect (MCE) is a prime candidate for the next generation of cooling systems. The essential components of magnetic refrigeration are the magnetic field generator and the magnetocaloric material. Although, several permanent magnet systems (magnetic field sources) for MR have been developed, recent development in magnetic refrigeration technology has encouraged researchers all over the world to think about new and original systems. This paper aims to describe a new and original magnetic refrigeration system based on a simple principle of magnetism called the Halbach effect. The proposed system is running with rotating bar-shaped magnets. This structure provides the desired varying magnetic field to the magnetocaloric material. Several configurations for the proposed systems have been investigated and presented in this paper. The design and modeling have been accomplished by using the finite elements method. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001952

Experimental study of a static system based on a magneto-thermal coupling in ferrofluids / M. Petit in International journal of refrigeration, Vol. 37 N° 1 (Janvier 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 201-208 Titre : Experimental study of a static system based on a magneto-thermal coupling in ferrofluids Titre original : Étude expérimentale d'une pompe statique fondée sur le couplage magnéto-thermique au sein des ferrofluides Type de document : texte imprimé Auteurs : M. Petit, Auteur ; Avenas, Yvan, Auteur ; A. Kedous-Lebouc, Auteur Année de publication : 2014 Article en page(s) : pp. 201-208 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Low  Curie  temperature  ferrofluids;  static  pump;  magnetothermal  coupling;  power  electronics  cooling Résumé : Liquid cooling of electronic devices requires generally a mechanical pump which reduces the performance of the system and its reliability. It has already been shown that ferrofluids with low Curie temperature are able to create a liquid flow without any mechanical part. In fact a pressure gradient can be obtained when subjecting this ferrofluids to both a temperature gradient and a magnetic field. In this paper a novel experimental setup is proposed. It is thermally and magnetically instrumented to achieve a precise analysis of the local behavior of the ferrofluids. A MnZn based ferrofluid was investigated on steady and transient states. The results confirm that a hydrostatic pressure can be successfully created. The behavior of the ferrofluid is analyzed considering a homogeneous applied magnetic field or not. A pressure drop is also highlighted and discussed in terms of temperature gradient evolution and magneto-convection in the ferrofluid. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002454 [article] Experimental study of a static system based on a magneto-thermal coupling in ferrofluids = Étude expérimentale d'une pompe statique fondée sur le couplage magnéto-thermique au sein des ferrofluides [texte imprimé] / M. Petit, Auteur ; Avenas, Yvan, Auteur ; A. Kedous-Lebouc, Auteur . - 2014 . - pp. 201-208. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 201-208 Mots-clés : Low  Curie  temperature  ferrofluids;  static  pump;  magnetothermal  coupling;  power  electronics  cooling Résumé : Liquid cooling of electronic devices requires generally a mechanical pump which reduces the performance of the system and its reliability. It has already been shown that ferrofluids with low Curie temperature are able to create a liquid flow without any mechanical part. In fact a pressure gradient can be obtained when subjecting this ferrofluids to both a temperature gradient and a magnetic field. In this paper a novel experimental setup is proposed. It is thermally and magnetically instrumented to achieve a precise analysis of the local behavior of the ferrofluids. A MnZn based ferrofluid was investigated on steady and transient states. The results confirm that a hydrostatic pressure can be successfully created. The behavior of the ferrofluid is analyzed considering a homogeneous applied magnetic field or not. A pressure drop is also highlighted and discussed in terms of temperature gradient evolution and magneto-convection in the ferrofluid. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002454

Multiobjective optimization of AMR systems / H. R. E. H. Bouchekara in International journal of refrigeration, Vol. 37 N° 1 (Janvier 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 63-71 Titre : Multiobjective optimization of AMR systems Titre original : Optimisation multi-objectifs de systèmes de froid magnétique actif Type de document : texte imprimé Auteurs : H. R. E. H. Bouchekara, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur Année de publication : 2014 Article en page(s) : pp. 63-71 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : AMR;  optimal  design;  magnetic  refrigerator;  multiobjective  optimization Résumé : In this paper, computational algorithms of different multiobjective optimization techniques and their application for AMR systems are presented. In order to illustrate the effectiveness of the proposed methods, they have been demonstrated on a layered AMR bed, where four objective functions are considered, namely: the temperature span, the cooling energy, the number of cycles to reach steady state and the masse of the MCM. The weighted sum, weighted product, Keeney-Raiffa, distance to a reference goal and ε-constraint methods are described along with a comparative study of the results. The results from the multiobjective optimization methods are evaluated in terms of the supercriterion S and the Euclidean distance N. It is concluded that the results obtained using some methods, like the weighting methods, are properly balanced yielding the best compromise in the presence of conflicting objectives while some other methods, like the distance to a reference goal method and the ε-constraint method, allow to reach predefined goals or to respect additional constraints. Moreover, methods like distance to a reference one or the ε-constraint one need some expertise and insights. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002430 [article] Multiobjective optimization of AMR systems = Optimisation multi-objectifs de systèmes de froid magnétique actif [texte imprimé] / H. R. E. H. Bouchekara, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur . - 2014 . - pp. 63-71. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 37 N° 1 (Janvier 2014) . - pp. 63-71 Mots-clés : AMR;  optimal  design;  magnetic  refrigerator;  multiobjective  optimization Résumé : In this paper, computational algorithms of different multiobjective optimization techniques and their application for AMR systems are presented. In order to illustrate the effectiveness of the proposed methods, they have been demonstrated on a layered AMR bed, where four objective functions are considered, namely: the temperature span, the cooling energy, the number of cycles to reach steady state and the masse of the MCM. The weighted sum, weighted product, Keeney-Raiffa, distance to a reference goal and ε-constraint methods are described along with a comparative study of the results. The results from the multiobjective optimization methods are evaluated in terms of the supercriterion S and the Euclidean distance N. It is concluded that the results obtained using some methods, like the weighting methods, are properly balanced yielding the best compromise in the presence of conflicting objectives while some other methods, like the distance to a reference goal method and the ε-constraint method, allow to reach predefined goals or to respect additional constraints. Moreover, methods like distance to a reference one or the ε-constraint one need some expertise and insights. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002430

Numerical analysis of an active magnetic regenerator / J. Roudaut in International journal of refrigeration, Vol. 34 N° 8 (Décembre 2011) 

Public ISBD [article]  in International journal of refrigeration > Vol. 34 N° 8 (Décembre 2011) . - pp. 1797–1804 Titre : Numerical analysis of an active magnetic regenerator Titre original : Analyse numérique d'un un régénérateur actif magnétique Type de document : texte imprimé Auteurs : J. Roudaut, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur Année de publication : 2012 Article en page(s) : pp. 1797–1804 Note générale : Génie mécanique Langues : Anglais (eng) Mots-clés : Magnetic  refrigerator  Gadolinium  Plate  exchanger  Modelling  Performance Résumé : A one-dimensional transient model of an active magnetic regenerator has been developed. The magnetocaloric properties are calculated using the Mean field theory and the model is used to study the transient and steady state response of a parallel plate regenerator. A parametric study is performed and highlights the influence of the Number of Transfer Units, the Utilization, and the solid axial conductivity. Finally the magnetic field inhomogeneity and the fluid axial conductivity are found to have no significant influence on the regenerator performance. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001861 [article] Numerical analysis of an active magnetic regenerator = Analyse numérique d'un un régénérateur actif magnétique [texte imprimé] / J. Roudaut, Auteur ; A. Kedous-Lebouc, Auteur ; J.-P. Yonnet, Auteur . - 2012 . - pp. 1797–1804. Génie mécanique Langues : Anglais (eng) in International journal of refrigeration > Vol. 34 N° 8 (Décembre 2011) . - pp. 1797–1804 Mots-clés : Magnetic  refrigerator  Gadolinium  Plate  exchanger  Modelling  Performance Résumé : A one-dimensional transient model of an active magnetic regenerator has been developed. The magnetocaloric properties are calculated using the Mean field theory and the model is used to study the transient and steady state response of a parallel plate regenerator. A parametric study is performed and highlights the influence of the Number of Transfer Units, the Utilization, and the solid axial conductivity. Finally the magnetic field inhomogeneity and the fluid axial conductivity are found to have no significant influence on the regenerator performance. ISSN : 0140-7007 En ligne : http://www.sciencedirect.com/science/article/pii/S0140700711001861