Les principaux domaines d’activité du Modelisation Group sont :
Études mathématiques de modèles issus de la physique et de la mécanique tels que les fluides magnétiques, l’interaction de particules avec une paroi et la magnéto-hydrodynamique.
Cet axe concerne l’étude mathématique et numérique de la dynamique de l’aimantation dans les matériaux ferromagnétiques et de la polarisation dans les matériaux ferroélectriques.
De sa production à son utilisation via la distribution. Optimiser l’adéquation entre la production et la consommation au travers des technologies de production, de stockage et du réseau intelligent de distribution.
Il s’agit d’optimiser les structures couplées ou non avec un fluide comme par exemple l’optimisation de la perte par transmission acoustique en utilisant les dimensions de la structure et les propriétés des matériaux.
L’équipe d’enseignants-chercheurs Modelisation Group issus de l’ESILV.
L’ensemble des travaux des enseignants-chercheurs Modelisation Group.
2015 |
Articles de journaux |
Antonio Gaudiello; Kamel Hamdache A reduced model for the polarization in a ferroelectric thin wire Article de journal Dans: Nonlinear Differential Equations and Applications NoDEA, 22 (6,22), p. 1883-1896, 2015. @article{Gaudiello2015, title = {A reduced model for the polarization in a ferroelectric thin wire}, author = {Antonio Gaudiello and Kamel Hamdache}, year = {2015}, date = {2015-01-01}, journal = {Nonlinear Differential Equations and Applications NoDEA}, volume = {22}, number = {6,22}, pages = {1883-1896}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Conférences |
Bassem Benlazreg; Achraf Kallel; Alexis Massol Optimized design for 3D printing 5500 - 5599 Conférence The 8th European Altair Technology Conference, ATC2015, October1, Paris, France, 2015. @conference{ATC2015, title = {Optimized design for 3D printing}, author = {Bassem Benlazreg and Achraf Kallel and Alexis Massol}, year = {2015}, date = {2015-10-01}, booktitle = {The 8th European Altair Technology Conference, ATC2015, October1, Paris, France}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
inproceedings |
Jérémy Oignet; Anthony Delahaye; Thomas Dufour; Hong-Minh Hoang; Pascal Clain; Laurence Fournaison Energy study of CO2 hydrate slurries formation in a tank reactor Inproceedings Dans: 24rd IIR International Congress of Refrigeration (ICR 2015), Aug 16-22 Yokohama, Japan, 2015. @inproceedings{Oignet2015, title = {Energy study of CO2 hydrate slurries formation in a tank reactor}, author = {Jérémy Oignet and Anthony Delahaye and Thomas Dufour and Hong-Minh Hoang and Pascal Clain and Laurence Fournaison}, year = {2015}, date = {2015-08-16}, booktitle = {24rd IIR International Congress of Refrigeration (ICR 2015)}, address = {Yokohama, Japan}, organization = {Aug 16-22}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Pascal Clain; Véronique Osswald; Olivier Spiga; Anthony Delahaye; Laurence Fournaison A new formation kinetics study method of TBPB and CO2 hydrates based on DTA Inproceedings Dans: 24rd IIR International Congress of Refrigeration (ICR 2015), Aug 16-22 Yokohama, Japan, 2015. @inproceedings{Clain2015, title = {A new formation kinetics study method of TBPB and CO2 hydrates based on DTA}, author = {Pascal Clain and Véronique Osswald and Olivier Spiga and Anthony Delahaye and Laurence Fournaison}, year = {2015}, date = {2015-08-16}, booktitle = {24rd IIR International Congress of Refrigeration (ICR 2015)}, address = {Yokohama, Japan}, organization = {Aug 16-22}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Trung Hieu Hoang; Mohamed Guerich; Julien Yvonnet Effective size of RVE for finite element analysis of structures made of nonlinear random composites Inproceedings Dans: 18th International Conference on Composite Structures (ICCS18), Lisbonne, Portugal, 2015. @inproceedings{hoang:hal-01166513, title = {Effective size of RVE for finite element analysis of structures made of nonlinear random composites}, author = { Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet}, url = {https://hal-upec-upem.archives-ouvertes.fr/hal-01166513}, year = {2015}, date = {2015-06-01}, booktitle = {18th International Conference on Composite Structures (ICCS18)}, address = {Lisbonne, Portugal}, abstract = {In the present work, we propose to determine the size of a representative volume element (RVE) in the case of nonlinear random composites with either elastoplastic or elasto viscoplastic phases. In such a case, the general form of the effective constitutive behavior is not known in advance and the response must be evaluated either by direct numerical computations on the RVE, either by an appropriate approximation scheme. Previous methodologies [1,2] for determining the size of RVE usually rely on analyzing the convergence of the RVE response computed numerically with respect to its size. In the present work, we analyze the convergence of parameters related to an incremental homogenization scheme, with respect to (i) the size of the RVE and (ii) to statistical convergence related to microstructure realizations. For that purpose, we combine an incremental homogenization method [3] with a statistical convergence analysis of parameters related to the matrix phase only. The advantage is that the range of parameters to be identified is much narrower than for a general empirical constitutive law. Once identified and the convergence analysis performed with respect to both size of RVE and statistical realizations, the macroscopic constitutive law can be readily used for structure calculations. We illustrate the methodology by analyzing two-dimensional microstructures with randomly distributed cylindrical elastic rigid fibers, embedded in a elastoplastic or elasto-viscoplastic matrix. For these materials, the existence of an RVE is demonstrated for sizes of RVE corresponding to 17 − 18 and 14 − 15 times the diameter of the inclusions, respectively. Effective size of RVE for finite element analysis of structures made of nonlinear random composites - ResearchGate. Available from: http://www.researchgate.net/publication/279488878_Effective_size_of_RVE_for_finite_element_analysis_of_structures_made_of_nonlinear_random_composites [accessed Jul 24, 2015].}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } In the present work, we propose to determine the size of a representative volume element (RVE) in the case of nonlinear random composites with either elastoplastic or elasto viscoplastic phases. In such a case, the general form of the effective constitutive behavior is not known in advance and the response must be evaluated either by direct numerical computations on the RVE, either by an appropriate approximation scheme. Previous methodologies [1,2] for determining the size of RVE usually rely on analyzing the convergence of the RVE response computed numerically with respect to its size. In the present work, we analyze the convergence of parameters related to an incremental homogenization scheme, with respect to (i) the size of the RVE and (ii) to statistical convergence related to microstructure realizations. For that purpose, we combine an incremental homogenization method [3] with a statistical convergence analysis of parameters related to the matrix phase only. The advantage is that the range of parameters to be identified is much narrower than for a general empirical constitutive law. Once identified and the convergence analysis performed with respect to both size of RVE and statistical realizations, the macroscopic constitutive law can be readily used for structure calculations. We illustrate the methodology by analyzing two-dimensional microstructures with randomly distributed cylindrical elastic rigid fibers, embedded in a elastoplastic or elasto-viscoplastic matrix. For these materials, the existence of an RVE is demonstrated for sizes of RVE corresponding to 17 − 18 and 14 − 15 times the diameter of the inclusions, respectively. Effective size of RVE for finite element analysis of structures made of nonlinear random composites - ResearchGate. Available from: http://www.researchgate.net/publication/279488878_Effective_size_of_RVE_for_finite_element_analysis_of_structures_made_of_nonlinear_random_composites [accessed Jul 24, 2015]. |
Trung Hieu Hoang; Mohamed Guerich; Julien Yvonnet An incremental multilevel computational homogenization method for elastoplastic composites Inproceedings Dans: 18th International Conference on Composite Structures (ICCS18), Lisbonne, Portugal, 2015. @inproceedings{hoang:hal-01166485, title = {An incremental multilevel computational homogenization method for elastoplastic composites}, author = {Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet}, url = {https://hal-upec-upem.archives-ouvertes.fr/hal-01166485}, year = {2015}, date = {2015-06-01}, booktitle = {18th International Conference on Composite Structures (ICCS18)}, address = {Lisbonne, Portugal}, abstract = {In the present work, a multilevel computational homogenization method is proposed for solving structure problems made of elastoplastic phases. To reduce computations costs of classical multi- level finite element methods [2], we use an incremental framework, initiated in Hill citehill1965 and developed for semi-analytical method e.g. in [1]. In semi-analytical approaches, the approx- imation of the Mori-Tanaka scheme induces limitations in accuracy for some configurations like strongly anisotropic microstructures and does not allow capturing effective smooth hardening in- duced by the different elastoplastic phases. In the proposed method, we use the incremental ap- proach by computing directly the effective macroscopic tensor related to the linearized problem numerically by Finite Elements on an RVE. The method is validated through an example of ho- mogenization of a composite microstructure with elastic rigid fibers, embedded in an elastoplastic matrix. The results showed that the method is more accurate than semi-anlytical methods and is less computationally demanding than FE2. An incremental multilevel computational homogenization method for elastoplastic composites - }, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } In the present work, a multilevel computational homogenization method is proposed for solving structure problems made of elastoplastic phases. To reduce computations costs of classical multi- level finite element methods [2], we use an incremental framework, initiated in Hill citehill1965 and developed for semi-analytical method e.g. in [1]. In semi-analytical approaches, the approx- imation of the Mori-Tanaka scheme induces limitations in accuracy for some configurations like strongly anisotropic microstructures and does not allow capturing effective smooth hardening in- duced by the different elastoplastic phases. In the proposed method, we use the incremental ap- proach by computing directly the effective macroscopic tensor related to the linearized problem numerically by Finite Elements on an RVE. The method is validated through an example of ho- mogenization of a composite microstructure with elastic rigid fibers, embedded in an elastoplastic matrix. The results showed that the method is more accurate than semi-anlytical methods and is less computationally demanding than FE2. An incremental multilevel computational homogenization method for elastoplastic composites - |
Julien Yvonnet; A. Tognevi; Guy Bonnet; M. Guerich A filter-based computational homogenization method for handling non-separated scales problems Inproceedings Dans: 12e Colloque National en Calcul des Structures, Presqu’^ile de Giens, France, 2015. @inproceedings{yvonnet:hal-01166483b, title = {A filter-based computational homogenization method for handling non-separated scales problems}, author = { Julien Yvonnet and A. Tognevi and Guy Bonnet and M. Guerich}, url = {https://hal-upec-upem.archives-ouvertes.fr/hal-01166483}, year = {2015}, date = {2015-01-01}, booktitle = {12e Colloque National en Calcul des Structures}, address = {Presqu’^ile de Giens, France}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Julien Yvonnet; Guy Bonnet; A. Tognevi; M. Guerich Filter-based computational homogenization Inproceedings Dans: 1st Pan-American congress on computational mechanics, Buenos Aires, Argentina, 2015, (Conf'erence invit'ee). @inproceedings{yvonnet:hal-01147886, title = {Filter-based computational homogenization}, author = { Julien Yvonnet and Guy Bonnet and A. Tognevi and M. Guerich}, url = {https://hal-upec-upem.archives-ouvertes.fr/hal-01147886}, year = {2015}, date = {2015-01-01}, booktitle = {1st Pan-American congress on computational mechanics}, address = {Buenos Aires, Argentina}, note = {Conf'erence invit'ee}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Julien Yvonnet; A. Tognevi; Guy Bonnet; M. Guerich A filter-based computational homogenization method for handling non-separated scales problems Inproceedings Dans: 12e Colloque National en Calcul des Structures, Presqu’^ile de Giens, France, 2015. @inproceedings{yvonnet:hal-01166483, title = {A filter-based computational homogenization method for handling non-separated scales problems}, author = { Julien Yvonnet and A. Tognevi and Guy Bonnet and M. Guerich}, url = {https://hal-upec-upem.archives-ouvertes.fr/hal-01166483}, year = {2015}, date = {2015-01-01}, booktitle = {12e Colloque National en Calcul des Structures}, address = {Presqu’^ile de Giens, France}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
2014 |
Articles de journaux |
Cédric Adam; Salim Bouabdallah; Malek Zarroug; Habibou Maitournam Improved Numerical Integration for Locking Treatment in Isogeometric Structural Elements. Part I: Beams Article de journal Dans: Computer Methods in Applied Mechanics & Engineering, 279 , p. 1-28, 2014. @article{Bouabdallah2014c, title = {Improved Numerical Integration for Locking Treatment in Isogeometric Structural Elements. Part I: Beams}, author = { Cédric Adam and Salim Bouabdallah and Malek Zarroug and Habibou Maitournam}, year = {2014}, date = {2014-09-01}, journal = {Computer Methods in Applied Mechanics & Engineering}, volume = {279}, pages = {1-28}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Wei Lin; Pascal Clain; Didier Dalmazzone; Walter Fürst; Anthony Delahaye; Laurence Fournaison Thermodynamic properties of semiclathrate hydrates formed from the TBAB+TBPB+water and CO2+TBAB+TBPB+water systems Article de journal Dans: Fluid Phase Equilibria, 372 , p. 63–68, 2014. @article{LCDFDF14, title = {Thermodynamic properties of semiclathrate hydrates formed from the TBAB+TBPB+water and CO2+TBAB+TBPB+water systems}, author = { Wei Lin and Pascal Clain and Didier Dalmazzone and Walter Fürst and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2014/LCDFDF14}, year = {2014}, date = {2014-01-01}, journal = {Fluid Phase Equilibria}, volume = {372}, pages = {63--68}, abstract = {Semiclathrate hydrates formed from binary systems of tetra-n-butylammonium bromide (TBAB) + water and tetra-n-butylphosphonium bromide (TBPB) + water have been investigated for their promising application in the refrigeration system. In the present work, semiclathrate hydrates in the ternary system of TBAB + TBPB + water were studied for the first time, in the presence and absence of CO2 pressure. Using DSC technique, the dissociation temperatures of semiclathrate hydrates were determined at the mass fraction of salt mixture ranges from 0.05 to 0.60 with variable composition from pure TBAB to pure TBPB. At any salt concentration tested, the dissociation temperature of semiclathrate hydrates increased regularly with TBAB composition increase. Applying CO2 pressure in the TBAB + TBPB + water system resulted in further increase of dissociation temperature due to the gas enclathration in the mixed hydrate structure. The phase transition enthalpy of semiclathrate hydrates were investigated at wsalts = 0.40 and variable TBPB compositions, without CO2 and with p CO 2 = 1.0 ? MPa . It was found that the dissociation enthalpies of CO2-free and CO2-containing semiclathrate hydrates are almost independent of the TBPB salt composition. From our current results, TBAB + TBPB + CO2 hydrates appear as valuable phase change materials to be used as hydrate slurries for cold storage and transportation in applications requiring variable working temperatures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Semiclathrate hydrates formed from binary systems of tetra-n-butylammonium bromide (TBAB) + water and tetra-n-butylphosphonium bromide (TBPB) + water have been investigated for their promising application in the refrigeration system. In the present work, semiclathrate hydrates in the ternary system of TBAB + TBPB + water were studied for the first time, in the presence and absence of CO2 pressure. Using DSC technique, the dissociation temperatures of semiclathrate hydrates were determined at the mass fraction of salt mixture ranges from 0.05 to 0.60 with variable composition from pure TBAB to pure TBPB. At any salt concentration tested, the dissociation temperature of semiclathrate hydrates increased regularly with TBAB composition increase. Applying CO2 pressure in the TBAB + TBPB + water system resulted in further increase of dissociation temperature due to the gas enclathration in the mixed hydrate structure. The phase transition enthalpy of semiclathrate hydrates were investigated at wsalts = 0.40 and variable TBPB compositions, without CO2 and with p CO 2 = 1.0 ? MPa . It was found that the dissociation enthalpies of CO2-free and CO2-containing semiclathrate hydrates are almost independent of the TBPB salt composition. From our current results, TBAB + TBPB + CO2 hydrates appear as valuable phase change materials to be used as hydrate slurries for cold storage and transportation in applications requiring variable working temperatures. |
Frédérick Mballa-Mballa; Olivier Hubert; Song He; Sophie Depeyre; Philip Meilland Micromagnetic Modeling of Magneto-Mechanical Behavior Article de journal Dans: IEEE Transactions on Magnetics, 50 (4), p. 1–4, 2014, ISSN: 0018-9464. @article{Mballa_IEEE, title = {Micromagnetic Modeling of Magneto-Mechanical Behavior}, author = {Frédérick Mballa-Mballa and Olivier Hubert and Song He and Sophie Depeyre and Philip Meilland}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6798024}, doi = {10.1109/TMAG.2013.2288911}, issn = {0018-9464}, year = {2014}, date = {2014-01-01}, journal = {IEEE Transactions on Magnetics}, volume = {50}, number = {4}, pages = {1--4}, publisher = {IEEE}, abstract = {A magneto-mechanical static modeling of ferromagnetic particle based on minimization of an energy function is presented. This modeling is made of a conjugate gradient method coupled with finite-element method for the mechanical problem resolution. Two-dimensional computational results highlighting the influence of magneto-mechanical coupling on the magnetic microstructure and behavior are reported.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A magneto-mechanical static modeling of ferromagnetic particle based on minimization of an energy function is presented. This modeling is made of a conjugate gradient method coupled with finite-element method for the mechanical problem resolution. Two-dimensional computational results highlighting the influence of magneto-mechanical coupling on the magnetic microstructure and behavior are reported. |
Xingjun Wang; Olivier Hubert; Song HE; Frédérick MBALLA-MBALLA; Ying HUANG Reversible magnetomechanical modeling of heterogeneous media Article de journal Dans: Journal Superconduc Novel Magnetism, 27 (9), p. 2049–2058, 2014, ISSN: 1557-1939. @article{Wang_Superconduc, title = {Reversible magnetomechanical modeling of heterogeneous media}, author = {Xingjun Wang and Olivier Hubert and Song HE and Frédérick MBALLA-MBALLA and Ying HUANG}, doi = {10.1007/s10948-014-2536-x}, issn = {1557-1939}, year = {2014}, date = {2014-01-01}, journal = {Journal Superconduc Novel Magnetism}, volume = {27}, number = {9}, pages = {2049--2058}, publisher = {Springer US}, abstract = {Localization and homogenization of the magnetomechanical fields in heterogeneous media are discussed. The magnetoelastic modeling for magnetic polycrystals is extended from the description of the singlecrystal modeling. This model is then applied to the prediction of the behavior of dual-phase steels. Each phase can be considered as a sphere embedded in a homogeneous equivalent medium. The magnetic model used for each phase is an explicit single-crystalline model representative of the behavior of the corresponding phase. Homogenization rules allow the simulation of the average medium. Experiments are carried out and compared to the numerical results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Localization and homogenization of the magnetomechanical fields in heterogeneous media are discussed. The magnetoelastic modeling for magnetic polycrystals is extended from the description of the singlecrystal modeling. This model is then applied to the prediction of the behavior of dual-phase steels. Each phase can be considered as a sphere embedded in a homogeneous equivalent medium. The magnetic model used for each phase is an explicit single-crystalline model representative of the behavior of the corresponding phase. Homogenization rules allow the simulation of the average medium. Experiments are carried out and compared to the numerical results. |
Conférences |
Morad Lakhssassi; Salim Bouabdallah Typology analysis for the optimization of a stamping process 5500 - 5599 Conférence 11th World Congress on Computational Mechanics (WCCM XI), Barcelona, 2014. @conference{Bouabdallah2014, title = {Typology analysis for the optimization of a stamping process}, author = { Morad Lakhssassi and Salim Bouabdallah}, year = {2014}, date = {2014-07-20}, publisher = {11th World Congress on Computational Mechanics (WCCM XI), Barcelona}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Cédric Adam; Salim Bouabdallah; Malek Zarroug; Habibou Maitournam Numerical integration for locking treatment in isogeometric structural elements 5500 - 5599 Conférence Isogeometric Analysis Applications (IGAAA 2014), Annweiler Am Trifels, Germany, 2014. @conference{Bouabdallah2014b, title = {Numerical integration for locking treatment in isogeometric structural elements}, author = { Cédric Adam and Salim Bouabdallah and Malek Zarroug and Habibou Maitournam}, year = {2014}, date = {2014-04-07}, publisher = {Isogeometric Analysis Applications (IGAAA 2014), Annweiler Am Trifels, Germany}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Thèses |
Pascal Clain Couplage entre le stockage et la distribution de froid par coulis d hydrates Thèse de doctorat Université Pierre et Marie Curie, 2014. @phdthesis{Cla14, title = {Couplage entre le stockage et la distribution de froid par coulis d hydrates}, author = { Pascal Clain}, url = {http://labs.esilv.fr/publications/public/2014/Cla14}, year = {2014}, date = {2014-01-01}, school = {Université Pierre et Marie Curie}, abstract = {The use of hydrate slurries as two-phase secondary refrigerants (FFD) reduces the environmental impact of refrigeration systems because these fluids have a high energy density. They can be used for cold storage will be a solution at an industrial problem of cold distribution at various temperature levels (air-conditioning, cooling process or preservation temperature). In this work, we study the coupling between a storage device and a cold distribution system by hydrate slurries. For achieve this objective, a two-stage reactor has been built for simulate the process. Equilibrium conditions studies for single and mixed hydrate showed an equilibrium temperature shift in porous media without deterioration of latent heat fusion. Hydrates formation/dissociation kinetics have been studied according to crystallization classical theories and an empirical model was obtained. Rheological studies of hydrate slurries emphasized a shear-thinning behavior for both, but a high propensity for agglomeration for mixed hydrate slurry. Particle size analysis showed the slurry has bimodal crystals distribution. Experimental set-up characterization showed process parameters effect in induction time. A 2D numerical tool integrating various empirical relations was developed for modelling temperature profile in the reactor and was validated in a first approach}, keywords = {}, pubstate = {published}, tppubtype = {phdthesis} } The use of hydrate slurries as two-phase secondary refrigerants (FFD) reduces the environmental impact of refrigeration systems because these fluids have a high energy density. They can be used for cold storage will be a solution at an industrial problem of cold distribution at various temperature levels (air-conditioning, cooling process or preservation temperature). In this work, we study the coupling between a storage device and a cold distribution system by hydrate slurries. For achieve this objective, a two-stage reactor has been built for simulate the process. Equilibrium conditions studies for single and mixed hydrate showed an equilibrium temperature shift in porous media without deterioration of latent heat fusion. Hydrates formation/dissociation kinetics have been studied according to crystallization classical theories and an empirical model was obtained. Rheological studies of hydrate slurries emphasized a shear-thinning behavior for both, but a high propensity for agglomeration for mixed hydrate slurry. Particle size analysis showed the slurry has bimodal crystals distribution. Experimental set-up characterization showed process parameters effect in induction time. A 2D numerical tool integrating various empirical relations was developed for modelling temperature profile in the reactor and was validated in a first approach |
la proc |
Trung Hieu Hoang; Mohamed Guerich; Julien Yvonnet 11th. World Congress on Computational Mechanics (WCCM XI), Barcelona, SPAIN, 2014. @proceedings{HOANG2014b, title = {A decoupled approach for computing the response of structures made of heterogeneous, random elastoplactic composites with hardening}, author = { Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet}, url = {https://www.esilv.fr/ecole-ingenieur/wp-content/uploads/2014/07/a1303.pdf}, year = {2014}, date = {2014-07-25}, publisher = {11th. World Congress on Computational Mechanics (WCCM XI)}, address = {Barcelona, SPAIN}, abstract = {A decoupled approach for computing the response of structures made of heterogeneous, random elastoplactic composites with hardening}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } A decoupled approach for computing the response of structures made of heterogeneous, random elastoplactic composites with hardening |
Amen Tognevi; Mohamed Guerich; Julien Yvonnet 11th. World Congress on Computational Mechanics (WCCM XI), Barcelona, SPAIN, 2014. @proceedings{atognevi2014b, title = {Computational modelling of heterogeneous structures without scale separation: an approach based on nonlocal filter-based homogenization}, author = { Amen Tognevi and Mohamed Guerich and Julien Yvonnet}, url = {https://www.esilv.fr/ecole-ingenieur/wp-content/uploads/2014/07/a3013.pdf}, year = {2014}, date = {2014-07-20}, publisher = {11th. World Congress on Computational Mechanics (WCCM XI)}, address = {Barcelona, SPAIN}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } |
Trung Hieu Hoang; Mohamed Guerich; Julien Yvonnet A procedure to determine the size of RVE nonlinear random heterogeneous material based on an incremental homogenization method procédure Stony Brook University Mechanics of Composites 2014 (MECHCOMP2014), June 8 - 12, 2014, USA, 2014. @proceedings{HOANG2014, title = {A procedure to determine the size of RVE nonlinear random heterogeneous material based on an incremental homogenization method}, author = { Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet}, year = {2014}, date = {2014-06-08}, publisher = {Mechanics of Composites 2014 (MECHCOMP2014), June 8 - 12, 2014}, address = {USA}, organization = {Stony Brook University}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } |
Dépubli |
Radoin Belaouar; Arash Fahim; Nizar Touzi Optimal Production Policy in Carbon Emission Marke (preprint) Dépubli 2014. @unpublished{carbon, title = {Optimal Production Policy in Carbon Emission Marke (preprint)}, author = { Radoin Belaouar and Arash Fahim and Nizar Touzi}, year = {2014}, date = {2014-01-01}, abstract = {The aim of this paper is to address the effect of the carbon emission allowance market on the production policy of a polluter production firm. We investigate this effect in three cases; when the firm is not a large polluter, when it has a large contribution in emission of carbon but can not affect the risk premium of the allowance market, and when it is a large contributor in the emission of carbon and can change the risk premium by its production. In our simple model, we ignore any possible investment of the firm in pollution reducing technologies. We formulate the problem of optimal production by a stochastic optimization problem. Then, we show that, as expected, the market reduces the optimal production policy in the first two cases. However, when the large producer activities can change the market risk premium, the cut on the production and consequently pollution cannot be guaranteed. In fact, our numerical test shows that for some models in our framework, the increase in production, and thus pollution, can increase the profit of the firm.}, keywords = {}, pubstate = {published}, tppubtype = {unpublished} } The aim of this paper is to address the effect of the carbon emission allowance market on the production policy of a polluter production firm. We investigate this effect in three cases; when the firm is not a large polluter, when it has a large contribution in emission of carbon but can not affect the risk premium of the allowance market, and when it is a large contributor in the emission of carbon and can change the risk premium by its production. In our simple model, we ignore any possible investment of the firm in pollution reducing technologies. We formulate the problem of optimal production by a stochastic optimization problem. Then, we show that, as expected, the market reduces the optimal production policy in the first two cases. However, when the large producer activities can change the market risk premium, the cut on the production and consequently pollution cannot be guaranteed. In fact, our numerical test shows that for some models in our framework, the increase in production, and thus pollution, can increase the profit of the firm. |
2013 |
Articles de journaux |
Shiva Kumar Malapaka; Bruno Després; Rémy Sart Unconditionally stable numerical simulations of a new generalized reduced resistive magnetohydrodynamics model Article de journal Dans: International Journal for Numerical Methods in Fluids, 74 (4), p. 231-249, 2013. @article{Malapaka2013, title = {Unconditionally stable numerical simulations of a new generalized reduced resistive magnetohydrodynamics model}, author = { Shiva Kumar Malapaka and Bruno Després and Rémy Sart}, url = {http://onlinelibrary.wiley.com/doi/10.1002/fld.3847/abstract}, year = {2013}, date = {2013-10-10}, journal = {International Journal for Numerical Methods in Fluids}, volume = {74}, number = {4}, pages = {231-249}, abstract = {Reduced-resistive magnetohydrodynamics (MHD) models are used in understanding different phenomenon in various domains, for example, astrophysics to model magnetotail or for solar arcades [Finn Bozkaya JM, Guzdar PN. Loss of equilibrium and reconnection in tearing of two dimensional equilibrias. Physics of Fluids B 1993; 5:2870–2876], modeling plasma confinements in reverse field pinch [Strauss HR. The dynamo effect in fusion plasmas. Physics of Fluids 1985; 28:2786–2792] and tokamaks [Strauss HR. Reduced MHD in nearly potential magnetic fields. Journal of Plasma Physics 1997; 57(1):83–87; Freidberg J. Plasma Physics and Fusion Energy. Cambridge University Press: Cambridge, 2008]. In this context, recently, a new generalized reduced-resistive MHD model, which can make use of an arbitrary density profile was proposed [Després B, Sart R. Reduced resistive MHD in Tokamaks with general density. ESAIM: Mathematical Modelling and Numerical Analysis 2012; 46(5):1081–1106. EDP Sciences, SMAI, 2012 online 2011]. We in this work show that this proposed theoretical model can be realized numerically as well, and that it is very robust if the equation set is written in a very particular form using the properties of FEM. To illustrate these points, we pick the current hole configuration [Fujita T, Oikawa T, Suzuki?T, Ide S, Sakamoto Y, Koide Y, Hatae T, Naito O, Isayama A, Hayashi N, Shirai H. Plasma equilibrium and confinement in a tokamak with nearly zero central current density in JT-60U. Physical Review Letters 2001; 87(11):245001; Hawkes NC, Stratton BC, Tala T, Challis CD, Conway G, DeAngelis R, Giroud C, Hobirk J, Joffrin E, Lomas P, Lotte P, Mailloux J, Mazon D, Rachlew E, Reyes-Cortes S, Solano E, Zastrow K-D. Observation of zero current density in the core of JET discharges with lower hybrid heating and current drive. Physical Review Letters 2001; 87(11):115001], which was modeled using reduced-resistive MHD and remodel it using different combinations of current sources and density profiles. Our model can be implemented with reasonable computational resources at the price of solving a well-posed global linear system and it is unconditionally stable. These features are also demonstrated as a part of our numerical experiments. Copyright © 2013 John Wiley & Sons, Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Reduced-resistive magnetohydrodynamics (MHD) models are used in understanding different phenomenon in various domains, for example, astrophysics to model magnetotail or for solar arcades [Finn Bozkaya JM, Guzdar PN. Loss of equilibrium and reconnection in tearing of two dimensional equilibrias. Physics of Fluids B 1993; 5:2870–2876], modeling plasma confinements in reverse field pinch [Strauss HR. The dynamo effect in fusion plasmas. Physics of Fluids 1985; 28:2786–2792] and tokamaks [Strauss HR. Reduced MHD in nearly potential magnetic fields. Journal of Plasma Physics 1997; 57(1):83–87; Freidberg J. Plasma Physics and Fusion Energy. Cambridge University Press: Cambridge, 2008]. In this context, recently, a new generalized reduced-resistive MHD model, which can make use of an arbitrary density profile was proposed [Després B, Sart R. Reduced resistive MHD in Tokamaks with general density. ESAIM: Mathematical Modelling and Numerical Analysis 2012; 46(5):1081–1106. EDP Sciences, SMAI, 2012 online 2011]. We in this work show that this proposed theoretical model can be realized numerically as well, and that it is very robust if the equation set is written in a very particular form using the properties of FEM. To illustrate these points, we pick the current hole configuration [Fujita T, Oikawa T, Suzuki?T, Ide S, Sakamoto Y, Koide Y, Hatae T, Naito O, Isayama A, Hayashi N, Shirai H. Plasma equilibrium and confinement in a tokamak with nearly zero central current density in JT-60U. Physical Review Letters 2001; 87(11):245001; Hawkes NC, Stratton BC, Tala T, Challis CD, Conway G, DeAngelis R, Giroud C, Hobirk J, Joffrin E, Lomas P, Lotte P, Mailloux J, Mazon D, Rachlew E, Reyes-Cortes S, Solano E, Zastrow K-D. Observation of zero current density in the core of JET discharges with lower hybrid heating and current drive. Physical Review Letters 2001; 87(11):115001], which was modeled using reduced-resistive MHD and remodel it using different combinations of current sources and density profiles. Our model can be implemented with reasonable computational resources at the price of solving a well-posed global linear system and it is unconditionally stable. These features are also demonstrated as a part of our numerical experiments. Copyright © 2013 John Wiley & Sons, Ltd. |
Mohamed Guerich; Samir Assaf Optimization of Noise Transmission through Damped Sandwich Structures Article de journal Dans: Journal of Vibration and Acoustics, 135 (5), p. 1-13, 2013. @article{GUERICH2013, title = {Optimization of Noise Transmission through Damped Sandwich Structures}, author = { Mohamed Guerich and Samir Assaf}, url = {http://www.researchgate.net/publication/262456008_Optimization_of_Noise_Transmission_through_Damped_Sandwich_Structures}, year = {2013}, date = {2013-10-01}, journal = {Journal of Vibration and Acoustics}, volume = {135}, number = {5}, pages = {1-13}, abstract = {An optimization methodology to increase the noise transmission loss (TL) of damped sandwich structures is presented. The prediction of the TL uses a numerical tool based on a finite element formulation for the sandwich plate coupled to a boundary element method for the acoustic medium. This tool can be used for arbitrarily shaped three-layer sandwich plates with various boundary conditions and it is well adapted to parametric and optimization studies. First, a parametric study was conducted to choose the objective function, the constraints, and the pertinent design variables to use in the optimization problem which consist in reducing the sound power transmitted by a viscoelastically damped sandwich plate. Next, by constraining the acoustical behavior of the sandwich panel, the surface mass of the sandwich structure was minimized. It is shown that a significant reduction in the transmitted sound power can be achieved by selecting the appropriate geometric configuration and damping layer material.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An optimization methodology to increase the noise transmission loss (TL) of damped sandwich structures is presented. The prediction of the TL uses a numerical tool based on a finite element formulation for the sandwich plate coupled to a boundary element method for the acoustic medium. This tool can be used for arbitrarily shaped three-layer sandwich plates with various boundary conditions and it is well adapted to parametric and optimization studies. First, a parametric study was conducted to choose the objective function, the constraints, and the pertinent design variables to use in the optimization problem which consist in reducing the sound power transmitted by a viscoelastically damped sandwich plate. Next, by constraining the acoustical behavior of the sandwich panel, the surface mass of the sandwich structure was minimized. It is shown that a significant reduction in the transmitted sound power can be achieved by selecting the appropriate geometric configuration and damping layer material. |
Wei Lin; Pascal Clain; Didier Dalmazzone; Walter Fürst; Anthony Delahaye; Laurence Fournaison Accurate DSC measurement of the phase transition temperature in the TBPB–water system Article de journal Dans: The Journal of Chemical Thermodynamics, 61 , p. 132–137, 2013. @article{LCDFDF13a, title = {Accurate DSC measurement of the phase transition temperature in the TBPB–water system}, author = { Wei Lin and Pascal Clain and Didier Dalmazzone and Walter Fürst and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2013/LCDFDF13a}, year = {2013}, date = {2013-01-01}, journal = {The Journal of Chemical Thermodynamics}, volume = {61}, pages = {132--137}, abstract = {There is some disagreement in the literature on the phase transition temperatures of salt semi-clathrates, which melt incongruently due to the change of salt concentration in the liquid phase. By using differential scanning calorimetry (DSC), the phase transition temperatures of tetrabutylphosphonium bromide (TBPB) hydrates were investigated at 0.10 < wTBPB < 0.37 and atmospheric pressure. The freezing point of ice with the presence of NaCl was also studied as a reference. In this work, two DSC procedures were employed: dynamic and stepwise schemes, characterized by the maximum peak temperature Tpeak and inflection point temperature Tend, and final step temperature Tstep, respectively. The stepwise DSC scheme was validated by the measurement of the ice freezing point at wNaCl = 0.10, 0.15 and 0.18. For the dynamic scheme, we developed and tested a method to estimate the melting temperature of TBPB hydrates. This method, though having a higher uncertainty, was more efficient than the stepwise scheme. The phase transition temperatures of TBPB hydrates are presented with the accuracy of 0.1 K and compared with literature data.}, keywords = {}, pubstate = {published}, tppubtype = {article} } There is some disagreement in the literature on the phase transition temperatures of salt semi-clathrates, which melt incongruently due to the change of salt concentration in the liquid phase. By using differential scanning calorimetry (DSC), the phase transition temperatures of tetrabutylphosphonium bromide (TBPB) hydrates were investigated at 0.10 < wTBPB < 0.37 and atmospheric pressure. The freezing point of ice with the presence of NaCl was also studied as a reference. In this work, two DSC procedures were employed: dynamic and stepwise schemes, characterized by the maximum peak temperature Tpeak and inflection point temperature Tend, and final step temperature Tstep, respectively. The stepwise DSC scheme was validated by the measurement of the ice freezing point at wNaCl = 0.10, 0.15 and 0.18. For the dynamic scheme, we developed and tested a method to estimate the melting temperature of TBPB hydrates. This method, though having a higher uncertainty, was more efficient than the stepwise scheme. The phase transition temperatures of TBPB hydrates are presented with the accuracy of 0.1 K and compared with literature data. |
Pascal Clain; Fatou-Toutie Ndoye; Anthony Delahaye; Laurence Fournaison Dans: Frio Calor Aire Acondicionado, 41 (460), p. 3–10, 2013. @article{CNDF13, title = {Comportamiento de flujo y equilibrio de fases de las suspensiones de hidratos de TBPB (bromuro de tetra-n-butilfosfonio) en medios porosos para aplicaciones de refrigeracion}, author = { Pascal Clain and Fatou-Toutie Ndoye and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2013/CNDF13}, year = {2013}, date = {2013-01-01}, journal = {Frio Calor Aire Acondicionado}, volume = {41}, number = {460}, pages = {3--10}, abstract = {The present work investigates the use of hydrates, as appropriate media for cold storage and distribution in refrigeration applications. Previous studies showed that these hydrates are able to trap molecules of carbon dioxide resulting in mixed hydrates. Hydrate can be used as phase change material (PCM) for thermal energy storage and hydrate slurries could be a good solution for industrial issues of cold distribution at various temperature levels. In fact, hydrates formed from tetra-n-butylphosphonium bromide (TBPB) + water mixtures have equilibrium conditions required for air-conditioning applications, with melting temperature at 281 K at atmospheric pressure. Calorimetry devices were used for determining dissociation enthalpies of salt hydrates under vari-ous stability conditions and salt concentrations in bulk and porous media. The results reveal that TBPB hydrates formed in porous media at lower temperature than in bulk conditions for a constant pressure due to capillary forces. In order to characterize the flow behavior of hydrate slurries for cold distribution, a rheological study was carried out in a dynamic loop by the Ostwald method. Finally, FBRM probe was used for a particle size analysis of TBPB hydrate and showed a bimodal distribution which could be confirmed in further work in order to define a potential relation between hydrate particle size and rheological behavior of hydrate slurry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present work investigates the use of hydrates, as appropriate media for cold storage and distribution in refrigeration applications. Previous studies showed that these hydrates are able to trap molecules of carbon dioxide resulting in mixed hydrates. Hydrate can be used as phase change material (PCM) for thermal energy storage and hydrate slurries could be a good solution for industrial issues of cold distribution at various temperature levels. In fact, hydrates formed from tetra-n-butylphosphonium bromide (TBPB) + water mixtures have equilibrium conditions required for air-conditioning applications, with melting temperature at 281 K at atmospheric pressure. Calorimetry devices were used for determining dissociation enthalpies of salt hydrates under vari-ous stability conditions and salt concentrations in bulk and porous media. The results reveal that TBPB hydrates formed in porous media at lower temperature than in bulk conditions for a constant pressure due to capillary forces. In order to characterize the flow behavior of hydrate slurries for cold distribution, a rheological study was carried out in a dynamic loop by the Ostwald method. Finally, FBRM probe was used for a particle size analysis of TBPB hydrate and showed a bimodal distribution which could be confirmed in further work in order to define a potential relation between hydrate particle size and rheological behavior of hydrate slurry. |
Pierre Courbin; Irina Lupu; Joël Goossens Scheduling of hard real-time multi-phase multi-thread (MPMT) periodic tasks Article de journal Dans: Real-Time Systems, 49 (2), p. 239-266, 2013. @article{CLG13, title = {Scheduling of hard real-time multi-phase multi-thread (MPMT) periodic tasks}, author = { Pierre Courbin and Irina Lupu and Joël Goossens}, url = {http://labs.esilv.fr/publications/public/2013/CLG13}, year = {2013}, date = {2013-01-01}, journal = {Real-Time Systems}, volume = {49}, number = {2}, pages = {239-266}, abstract = {In this paper we study the scheduling of parallel and real-time recurrent tasks on multiprocessor platforms. Firstly, we propose a new parallel task model which allows recurrent tasks to be composed of several phases, each one composed of several threads. Each thread requires a single processor for execution and can be scheduled simultaneously. We then propose an algorithm to transpose popular Fork-Join task model to our MPMT task model. Secondly, we define several kinds of real-time schedulers that can be applied to our parallel task model. We distinguish between two scheduling classes: Hierarchical schedulers and Global Thread schedulers. We present and prove correct an exact schedulability test for each class. Lastly, we also evaluate the performance of our scheduling paradigm in comparison with Gang scheduling by means of simulations. In this work we extend the work of Lupu and Goossens in Scheduling of hard real-time multi-thread periodic tasks (Real-Time and Network Systems, 2011) which considers mono-phase multi-thread task model. We extend their previous results to a Multi-Phase Multi-Thread task model.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper we study the scheduling of parallel and real-time recurrent tasks on multiprocessor platforms. Firstly, we propose a new parallel task model which allows recurrent tasks to be composed of several phases, each one composed of several threads. Each thread requires a single processor for execution and can be scheduled simultaneously. We then propose an algorithm to transpose popular Fork-Join task model to our MPMT task model. Secondly, we define several kinds of real-time schedulers that can be applied to our parallel task model. We distinguish between two scheduling classes: Hierarchical schedulers and Global Thread schedulers. We present and prove correct an exact schedulability test for each class. Lastly, we also evaluate the performance of our scheduling paradigm in comparison with Gang scheduling by means of simulations. In this work we extend the work of Lupu and Goossens in Scheduling of hard real-time multi-thread periodic tasks (Real-Time and Network Systems, 2011) which considers mono-phase multi-thread task model. We extend their previous results to a Multi-Phase Multi-Thread task model. |
Wei Lin; Pascal Clain; Didier Dalmazzone; Walter Fürst; Anthony Delahaye; Laurence Fournaison Thermodynamic Studies of CO2 + TBAB + Water System: Experimental Measurements and Correlations Article de journal Dans: Journal of Chemical & Engineering Data, 58 (8), p. 2233–2239, 2013. @article{LCDFDF13, title = {Thermodynamic Studies of CO2 + TBAB + Water System: Experimental Measurements and Correlations}, author = { Wei Lin and Pascal Clain and Didier Dalmazzone and Walter Fürst and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2013/LCDFDF13}, year = {2013}, date = {2013-01-01}, journal = {Journal of Chemical & Engineering Data}, volume = {58}, number = {8}, pages = {2233--2239}, abstract = {Thermodynamic properties of TBAB + CO2 + water system are important for using TBAB + CO2 semiclathrate hydrates in some promising hydrate-based techniques. This work is an experimental and modeling study of two fundamental properties in vapor?liquid phase equilibrium of TBAB + CO2 + water, that is, CO2 solubility in TBAB solution and density of CO2-saturated TBAB solution. With the use of a PVT system, CO2 solubility was measured; thus, Henry?s constant was obtained at temperatures from 288.1 K to 303.1 K and TBAB mass fraction from 0.10 to 0.40. Our results showed that CO2 is either salted-in or salted-out by the presence of TBAB, depending upon the temperature and TBAB concentration. For the density, we present experimental data for TBAB + water system at T = 283.15 K to 303.15 K with pressures up to 5 MPa. The density of CO2-saturated TBAB aqueous solution was calculated with the help of Duan?s model, which takes into account the effect of pressure and temperature to calculate the apparent molar volume of dissolved CO2 in pure water.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Thermodynamic properties of TBAB + CO2 + water system are important for using TBAB + CO2 semiclathrate hydrates in some promising hydrate-based techniques. This work is an experimental and modeling study of two fundamental properties in vapor?liquid phase equilibrium of TBAB + CO2 + water, that is, CO2 solubility in TBAB solution and density of CO2-saturated TBAB solution. With the use of a PVT system, CO2 solubility was measured; thus, Henry?s constant was obtained at temperatures from 288.1 K to 303.1 K and TBAB mass fraction from 0.10 to 0.40. Our results showed that CO2 is either salted-in or salted-out by the presence of TBAB, depending upon the temperature and TBAB concentration. For the density, we present experimental data for TBAB + water system at T = 283.15 K to 303.15 K with pressures up to 5 MPa. The density of CO2-saturated TBAB aqueous solution was calculated with the help of Duan?s model, which takes into account the effect of pressure and temperature to calculate the apparent molar volume of dissolved CO2 in pure water. |
Conférences |
Achraf Kallel; Salim Bouabdallah; Jean-Marc Roelandt A review of different formulations for mortar contact constraint enforcement 5500 - 5599 Conférence 4° Congrès Algérien de Mécanique, Mascara, 2013. @conference{Bouabdallah2013, title = {A review of different formulations for mortar contact constraint enforcement}, author = { Achraf Kallel and Salim Bouabdallah and Jean-Marc Roelandt}, year = {2013}, date = {2013-11-25}, publisher = {4° Congrès Algérien de Mécanique, Mascara}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Cédric Adam; Salim Bouabdallah; Malek Zarroug; Habibou Maitournam Formulation of an Isogeometric shell element for crash simulation 5500 - 5599 Conférence XII International Conference on Computational Plasticity, Barcelona, 3-5 September 2013., 2013. @conference{Bouabdallah2013b, title = {Formulation of an Isogeometric shell element for crash simulation}, author = { Cédric Adam and Salim Bouabdallah and Malek Zarroug and Habibou Maitournam}, year = {2013}, date = {2013-09-03}, publisher = {XII International Conference on Computational Plasticity, Barcelona, 3-5 September 2013.}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Achraf Kallel; Salim Bouabdallah; Jean-Marc Roelandt A mortar algorithm for finite deformation contact problem 5500 - 5599 Conférence 21° Congrès Français de Mécanique, Bordeaux, 26 – 30 Août 2013, 2013. @conference{Bouabdallah2013bb, title = {A mortar algorithm for finite deformation contact problem}, author = { Achraf Kallel and Salim Bouabdallah and Jean-Marc Roelandt}, year = {2013}, date = {2013-08-26}, publisher = {21° Congrès Français de Mécanique, Bordeaux, 26 – 30 Août 2013}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Achraf Kallel; Salim Bouabdallah; Jean-Marc Roelandt A simple scheme for two dimensional mortar frictional contact problems 5500 - 5599 Conférence 3rd International Conference on Computational Contact Mechanics, Lecce, 10-12 July 2013, 2013. @conference{Bouabdallah2013bb, title = {A simple scheme for two dimensional mortar frictional contact problems}, author = { Achraf Kallel and Salim Bouabdallah and Jean-Marc Roelandt}, year = {2013}, date = {2013-07-10}, publisher = {3rd International Conference on Computational Contact Mechanics, Lecce, 10-12 July 2013}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
Cédric Adam; Salim Bouabdallah; Malek Zarroug; Habibou Maitournam Formulation d'un élément coque en analyse isogéométrique pour la simulation du choc 5500 - 5599 Conférence , 11e Colloque National en Calcul des Structures, Giens, 13-17 Mai 2013, 2013. @conference{Bouabdallah2013bb, title = {Formulation d'un élément coque en analyse isogéométrique pour la simulation du choc}, author = { Cédric Adam and Salim Bouabdallah and Malek Zarroug and Habibou Maitournam}, year = {2013}, date = {2013-05-13}, publisher = {, 11e Colloque National en Calcul des Structures, Giens, 13-17 Mai 2013}, keywords = {}, pubstate = {published}, tppubtype = {conference} } |
inproceedings |
Pascal Clain; Jeremy Oignet; Anthony Delahaye; Laurence Fournaison Experimental and thermodynamic of a cold storage hydrate slurries process Inproceedings Dans: Société Française des Génies des Procédés, Lyon, France, 2013. @inproceedings{CODF13, title = {Experimental and thermodynamic of a cold storage hydrate slurries process}, author = { Pascal Clain and Jeremy Oignet and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2013/CODF13}, year = {2013}, date = {2013-01-01}, booktitle = {Société Française des Génies des Procédés}, address = {Lyon, France}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Jeremy Oignet; Pascal Clain; Salem Jerbi; Anthony Delahaye; Laurence Fournaison Study of a secondary refrigeration loop hydrate slurries Inproceedings Dans: Société Française des Génies des Procédés, Lyon, France, 2013. @inproceedings{OCJDF13, title = {Study of a secondary refrigeration loop hydrate slurries}, author = { Jeremy Oignet and Pascal Clain and Salem Jerbi and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2013/OCJDF13}, year = {2013}, date = {2013-01-01}, booktitle = {Société Française des Génies des Procédés}, address = {Lyon, France}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
la proc |
Mohamed Guerich; Samir Assaf Design vibro-acoustic Optimization of Sandwich panels procédure INTERNOISE’2013, Innsbruck, AUSTRIA, 2013. @proceedings{GUERICH2013b, title = {Design vibro-acoustic Optimization of Sandwich panels}, author = { Mohamed Guerich and Samir Assaf}, year = {2013}, date = {2013-09-18}, publisher = {INTERNOISE’2013}, address = {Innsbruck, AUSTRIA}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } |
Trung Hieu Hoang; Mohamed Guerich; Julien Yvonnet Determination of the size of an RVE for nonlinear random composites procédure 3rd ICMM Int. Conference on Material Modelling incorporating, Warsaw, POLAND, 2013. @proceedings{HOANG2013, title = {Determination of the size of an RVE for nonlinear random composites}, author = { Trung Hieu Hoang and Mohamed Guerich and Julien Yvonnet}, year = {2013}, date = {2013-09-11}, publisher = {3rd ICMM Int. Conference on Material Modelling incorporating}, address = {Warsaw, POLAND}, keywords = {}, pubstate = {published}, tppubtype = {proceedings} } |
2012 |
Articles de journaux |
Bruno Després; Rémy Sart Reduced resistive MHD in Tokamaks with general density Article de journal Dans: ESAIM: Mathematical Modelling and Numerical Analysis, 46 (5), p. 1081-1106, 2012. @article{Després2012, title = {Reduced resistive MHD in Tokamaks with general density}, author = { Bruno Després and Rémy Sart}, url = {http://labs.esilv.fr/cs/sart/doc/MHD_reduite.pdf}, year = {2012}, date = {2012-02-13}, journal = {ESAIM: Mathematical Modelling and Numerical Analysis}, volume = {46}, number = {5}, pages = {1081-1106}, abstract = {The aim of this paper is to derive a general model for reduced viscous and resistive Magnetohydrodynamics (MHD) and to study its mathematical structure. The model is established for arbitrary density profiles in the poloidal section of the toroidal geometry of Tokamaks. The existence of global weak solutions, on the one hand, and the stability of the fundamental mode around initial data, on the other hand, are investigated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The aim of this paper is to derive a general model for reduced viscous and resistive Magnetohydrodynamics (MHD) and to study its mathematical structure. The model is established for arbitrary density profiles in the poloidal section of the toroidal geometry of Tokamaks. The existence of global weak solutions, on the one hand, and the stability of the fundamental mode around initial data, on the other hand, are investigated. |
Laurent Chupin; Rémy Sart Existence result for stationary compressible fluids and asymptotic behavior in thin films Article de journal Dans: Asymptotic Analysis, 76 (3-4), p. 193-231, 2012. @article{Chupin2012, title = {Existence result for stationary compressible fluids and asymptotic behavior in thin films}, author = { Laurent Chupin and Rémy Sart}, url = {http://labs.esilv.fr/cs/sart/doc/NS_Reynolds.pdf}, year = {2012}, date = {2012-01-01}, journal = {Asymptotic Analysis}, volume = {76}, number = {3-4}, pages = {193-231}, abstract = {In this paper, we are first interested in the compressible Navier–Stokes equations with density dependent viscosities in bounded domains with non-homogeneous Dirichlet conditions. We study the well posedness of such models with density dependent viscosity coefficients in the non-stationary and in the stationary cases. We apply the last result in thin domains context, justifying the compressible Reynolds equations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we are first interested in the compressible Navier–Stokes equations with density dependent viscosities in bounded domains with non-homogeneous Dirichlet conditions. We study the well posedness of such models with density dependent viscosity coefficients in the non-stationary and in the stationary cases. We apply the last result in thin domains context, justifying the compressible Reynolds equations. |
Pascal Clain; Anthony Delahaye; Laurence Fournaison; Nadia Mayoufi; Didier Dalmazzone; Walter Fürst Rheological properties of tetra-n-butylphosphonium bromide hydrate slurry flow Article de journal Dans: Chemical Engineering Journal, 193-194 , p. 112-122, 2012. @article{CDFMDF12, title = {Rheological properties of tetra-n-butylphosphonium bromide hydrate slurry flow}, author = { Pascal Clain and Anthony Delahaye and Laurence Fournaison and Nadia Mayoufi and Didier Dalmazzone and Walter Fürst}, url = {http://labs.esilv.fr/publications/public/2012/CDFMDF12}, year = {2012}, date = {2012-01-01}, journal = {Chemical Engineering Journal}, volume = {193-194}, pages = {112-122}, abstract = {Clathrate hydrate slurries can be considered as two-phase refrigerants due to their high energy densities. The heat of formation of many clathrate hydrates is higher than that observed for other phase change materials used in this field. The present work investigates the use of semiclathrate hydrates, formed from tetra-n-butylphosphonium bromide (TBPB) + water mixtures, as appropriate media for cold storage and distribution in refrigeration applications. Indeed, TBPB hydrates crystallize under atmospheric pressure and at temperatures around 281 K, which are suitable conditions for air-conditioning or refrigeration applications. In the present study, we focus on the rheological behaviour of TBPB hydrate slurry studied thanks to a dynamic loop and the application of Ostwald method. Volumetric flow rates and pressure drops are measured for hydrate fractions between 0 and 28.2 vol.%. The rheological properties deduced from these measurements were modelled using a semi-empirical Ostwald-de Waele law taking into account hydrate slurry fraction. Finally, the apparent viscosity of TBPB hydrate slurry was estimated from the model and a good agreement was found between our data and literature.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Clathrate hydrate slurries can be considered as two-phase refrigerants due to their high energy densities. The heat of formation of many clathrate hydrates is higher than that observed for other phase change materials used in this field. The present work investigates the use of semiclathrate hydrates, formed from tetra-n-butylphosphonium bromide (TBPB) + water mixtures, as appropriate media for cold storage and distribution in refrigeration applications. Indeed, TBPB hydrates crystallize under atmospheric pressure and at temperatures around 281 K, which are suitable conditions for air-conditioning or refrigeration applications. In the present study, we focus on the rheological behaviour of TBPB hydrate slurry studied thanks to a dynamic loop and the application of Ostwald method. Volumetric flow rates and pressure drops are measured for hydrate fractions between 0 and 28.2 vol.%. The rheological properties deduced from these measurements were modelled using a semi-empirical Ostwald-de Waele law taking into account hydrate slurry fraction. Finally, the apparent viscosity of TBPB hydrate slurry was estimated from the model and a good agreement was found between our data and literature. |
inproceedings |
Benjamin Bado; Laurent George; Pierre Courbin; Joël Goossens A semi-partitioned approach for parallel real-time scheduling Inproceedings Dans: International Conference on Real-Time and Network Systems, p. 151-160, ACM, 2012. @inproceedings{BGCG12, title = {A semi-partitioned approach for parallel real-time scheduling}, author = { Benjamin Bado and Laurent George and Pierre Courbin and Joël Goossens}, url = {http://labs.esilv.fr/publications/public/2012/BGCG12}, year = {2012}, date = {2012-01-01}, booktitle = {International Conference on Real-Time and Network Systems}, pages = {151-160}, publisher = {ACM}, abstract = {In this paper, we consider the problem of scheduling periodic Multi-Phase Multi-Thread tasks on a set of m identical processors with Earliest Deadline First (EDF) scheduling. Each periodic task is defined by a sequence of phases with offsets that can be possibly parallelized. We use a portioned semi-partitioned approach with migrations at local deadlines assigned to each phase. We extend this approach to take into account phase parallelism. The phase parallelism we consider is an extension of the popular job parallelism. A phase, if parallelizable, can be decomposed into parallel threads run on a configurable number of processors. We only require simultaneous execution of threads inside a window equal to the local deadline of their associated phase. To decide on the schedulability of a Multi-Phase Multi-Thread task, we extend the popular uniprocessor EDF feasibility condition for periodic asynchronous tasks. We propose two new schedulability tests for EDF that significantly improve the well known Leung and Merill feasibility test based on the feasibility interval [Omin, Omax + 2P], where Omin and Omax are respectively the minimum and maximum phase offsets and P the least common multiple of the task periods. The first schedulability test is used when an EDF simulation is needed and gives, by simulation, a 44% gain in simulation speed. The second method provides a sufficient schedulability test with a time interval of length P based on the demand bound function. Finally, we study three local deadline assignment heuristics assigned to parallelizable phases. We compare and analyze the performances obtained by simulation for those three local deadline assignment heuristics.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } In this paper, we consider the problem of scheduling periodic Multi-Phase Multi-Thread tasks on a set of m identical processors with Earliest Deadline First (EDF) scheduling. Each periodic task is defined by a sequence of phases with offsets that can be possibly parallelized. We use a portioned semi-partitioned approach with migrations at local deadlines assigned to each phase. We extend this approach to take into account phase parallelism. The phase parallelism we consider is an extension of the popular job parallelism. A phase, if parallelizable, can be decomposed into parallel threads run on a configurable number of processors. We only require simultaneous execution of threads inside a window equal to the local deadline of their associated phase. To decide on the schedulability of a Multi-Phase Multi-Thread task, we extend the popular uniprocessor EDF feasibility condition for periodic asynchronous tasks. We propose two new schedulability tests for EDF that significantly improve the well known Leung and Merill feasibility test based on the feasibility interval [Omin, Omax + 2P], where Omin and Omax are respectively the minimum and maximum phase offsets and P the least common multiple of the task periods. The first schedulability test is used when an EDF simulation is needed and gives, by simulation, a 44% gain in simulation speed. The second method provides a sufficient schedulability test with a time interval of length P based on the demand bound function. Finally, we study three local deadline assignment heuristics assigned to parallelizable phases. We compare and analyze the performances obtained by simulation for those three local deadline assignment heuristics. |
Vincent Sciandra; Pierre Courbin; Laurent George Application of Mixed-Criticality Scheduling Model to Intelligent Transportation Systems Architectures. Inproceedings Dans: IEEE Work-in-Progress Real-Time Systems Symposium, p. 22, ACM, 2012. @inproceedings{SCG12, title = {Application of Mixed-Criticality Scheduling Model to Intelligent Transportation Systems Architectures.}, author = { Vincent Sciandra and Pierre Courbin and Laurent George}, url = {http://labs.esilv.fr/publications/public/2012/SCG12}, year = {2012}, date = {2012-01-01}, booktitle = {IEEE Work-in-Progress Real-Time Systems Symposium}, volume = {10}, pages = {22}, publisher = {ACM}, series = {Work-in-Progress (WiP) Session}, abstract = {Intelligent Transportation Systems (ITS) usage has transformed public transports' vision on operation management. However, the lack of common communication interfaces has brought redundancy within on-board applications. In this context, the European Bus System of the Future (EBSF) project has specified a common architecture based on IP standards [1]. It provides a Service Oriented Architecture (SOA) that permits the ITS applications to publish services and subscribe to others. The EBSF architecture enables Vehicle To Infrastructure communications (V2I) through a unique communication gateway, with managing needs of the different data flows depending on their priority in the network and the available communication resources (bandwidth).}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Intelligent Transportation Systems (ITS) usage has transformed public transports' vision on operation management. However, the lack of common communication interfaces has brought redundancy within on-board applications. In this context, the European Bus System of the Future (EBSF) project has specified a common architecture based on IP standards [1]. It provides a Service Oriented Architecture (SOA) that permits the ITS applications to publish services and subscribe to others. The EBSF architecture enables Vehicle To Infrastructure communications (V2I) through a unique communication gateway, with managing needs of the different data flows depending on their priority in the network and the available communication resources (bandwidth). |
Pascal Clain; Anthony Delahaye; Laurence Fournaison DTA and DSC characterization of TBPB and TBPB+CO2 hydrates in porous media Inproceedings Dans: Calorimetry and thermal effects in catalysis, Lyon, France, 2012. @inproceedings{CDF12, title = {DTA and DSC characterization of TBPB and TBPB+CO2 hydrates in porous media}, author = { Pascal Clain and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2012/CDF12}, year = {2012}, date = {2012-01-01}, booktitle = {Calorimetry and thermal effects in catalysis}, address = {Lyon, France}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
Pascal Clain; Fatou-Toutie Ndoye; Anthony Delahaye; Laurence Fournaison Flow behavior and phase equilibrium of TBPB hydrate slurry in porous media for refrigeration application Inproceedings Dans: IIR conference on Phase-change materials and slurries for refrigeration and air-conditioning, IIR, Kobe, Japan, 2012. @inproceedings{CNDF12, title = {Flow behavior and phase equilibrium of TBPB hydrate slurry in porous media for refrigeration application}, author = { Pascal Clain and Fatou-Toutie Ndoye and Anthony Delahaye and Laurence Fournaison}, url = {http://labs.esilv.fr/publications/public/2012/CNDF12}, year = {2012}, date = {2012-01-01}, booktitle = {IIR conference on Phase-change materials and slurries for refrigeration and air-conditioning}, publisher = {IIR}, address = {Kobe, Japan}, abstract = {The present work investigates TBPB(tetra-n-butylphosphonium bromide) hydrate slurries based on focused beam reflectance measurement (FBRM) method. Hydrates can be used as phase change materials (PCM) for thermal energy storage due to their high latent heat of melting. In this study, hydrates were formed from TBPB-water mixtures, suitable for air-conditioning applications. Moreover, hydrate slurries, composed of hydrate-particles dispersed in liquid, are appropriate solutions for cold distribution. Nevertheless, flow properties of hydrate slurries, depending on hydrate crystallization kinetics, must be controlled. In this work, FBRM was used for analysing TBPB-hydrate-particle size distribution. This work showed that FBRM can detect system phase changes (nucleation, growth, agglomeration). In addition, a bimodal distribution of particles was observed. This work could be useful to understand rheological behaviour of hydrate slurry, not only for secondary refrigeration applications, but also for natural gas hydrate transportation, pipeline plugging prevention, and gas capture.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } The present work investigates TBPB(tetra-n-butylphosphonium bromide) hydrate slurries based on focused beam reflectance measurement (FBRM) method. Hydrates can be used as phase change materials (PCM) for thermal energy storage due to their high latent heat of melting. In this study, hydrates were formed from TBPB-water mixtures, suitable for air-conditioning applications. Moreover, hydrate slurries, composed of hydrate-particles dispersed in liquid, are appropriate solutions for cold distribution. Nevertheless, flow properties of hydrate slurries, depending on hydrate crystallization kinetics, must be controlled. In this work, FBRM was used for analysing TBPB-hydrate-particle size distribution. This work showed that FBRM can detect system phase changes (nucleation, growth, agglomeration). In addition, a bimodal distribution of particles was observed. This work could be useful to understand rheological behaviour of hydrate slurry, not only for secondary refrigeration applications, but also for natural gas hydrate transportation, pipeline plugging prevention, and gas capture. |
Technical Reports |
Song He; Sophie Depeyre; Yasmine Gabi; Olivier Geoffroy; Olivier Hubert; Afef Lebouc; Frédérick Mballa Mballa; Philip Meilland; Gérard Meunier Dual Phase Steels Magnetism Modeling Technical Report 2012. @techreport{He_Rapport_ANR, title = {Dual Phase Steels Magnetism Modeling}, author = {Song He and Sophie Depeyre and Yasmine Gabi and Olivier Geoffroy and Olivier Hubert and Afef Lebouc and Frédérick Mballa Mballa and Philip Meilland and Gérard Meunier}, year = {2012}, date = {2012-01-01}, pages = {45}, keywords = {}, pubstate = {published}, tppubtype = {techreport} } |
2011 |
Articles de journaux |
Erwan Deriaz; Bruno Després; Gloria Faccanoni; Kirill Gostaf; Lise-Marie Imbert-Gérard; Georges Sadaka; Rémy Sart Magnetic equations with Freefem++ : the Grad-Shafranov equation and the current hole Article de journal Dans: ESAIM: PROCEEDINGS, 32 , p. 76-94, 2011. @article{Deriaz2011, title = {Magnetic equations with Freefem++ : the Grad-Shafranov equation and the current hole}, author = { Erwan Deriaz and Bruno Després and Gloria Faccanoni and Kirill Gostaf and Lise-Marie Imbert-Gérard and Georges Sadaka and Rémy Sart}, url = {http://labs.esilv.fr/cs/sart/doc/emaff.pdf}, year = {2011}, date = {2011-11-03}, journal = {ESAIM: PROCEEDINGS}, volume = {32}, pages = {76-94}, abstract = {FreeFem++ [11] is a software for the numerical solution of partial differential equations. It is based on finite element method. The FreeFem++ platform aims at facilitating teaching and basic research through prototyping. For the moment this platform is restricted to the numerical simulations of problems which admit a variational formulation. Our goal in this work is to evaluate the FreeFem++ tool on basic magnetic equations arising in Fusion Plasma in the context of the ITER project. First we consider the Grad-Shafranov equation, which is derived from the static ideal MHD equations assuming axisymetry. Some of the properties of the equation and its analytical solutions are discussed. Second we discretize a reduced resistive MHD model which admits solutions of the Grad-Shafranov equation as stationary solutions. Then the physical stability of these stationary solutions is investigated through numerical experiments and the numerical stability of the algorithm is discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } FreeFem++ [11] is a software for the numerical solution of partial differential equations. It is based on finite element method. The FreeFem++ platform aims at facilitating teaching and basic research through prototyping. For the moment this platform is restricted to the numerical simulations of problems which admit a variational formulation. Our goal in this work is to evaluate the FreeFem++ tool on basic magnetic equations arising in Fusion Plasma in the context of the ITER project. First we consider the Grad-Shafranov equation, which is derived from the static ideal MHD equations assuming axisymetry. Some of the properties of the equation and its analytical solutions are discussed. Second we discretize a reduced resistive MHD model which admits solutions of the Grad-Shafranov equation as stationary solutions. Then the physical stability of these stationary solutions is investigated through numerical experiments and the numerical stability of the algorithm is discussed. |
Samir Assaf; Mohamed Guerich; Philippe Cuvelier Vibration and Damping Analysis of Plates with Partially Covered damping Layers Article de journal Dans: Acta Acustica United with Acustica, 97 , p. 553-568, 2011. @article{ASSAF2011, title = {Vibration and Damping Analysis of Plates with Partially Covered damping Layers}, author = { Samir Assaf and Mohamed Guerich and Philippe Cuvelier}, editor = {S. Hirzel Verlag}, url = {http://dx.doi.org/10.3813/AAA.918436}, year = {2011}, date = {2011-07-01}, journal = {Acta Acustica United with Acustica}, volume = {97}, pages = {553-568}, abstract = {The constrained-layer damping treatment is widely used to control the resonant response of vibrating structures, particularly in the automotive and aerospace industries. This technique requires design tools in order to select the best location, type and thickness of the damping and constraining-layer materials for optimum damping while minimizing the total weight of the damping treatments. In this study, a numerical tool is presented to analyze the vibration response of plates partially or fully covered with a constrained viscoelastic damping material. This tool is based on a finite element approach. The undamped plate structure is modeled using a discrete Kirchhoff theory (DKT) element. However, a sandwich plate element is specially derived to model the damped plate structure. This element is formulated in such a way that it is compatible with the DKT element. The natural frequencies and modal loss factors are derived from the modal strain energy method. The proposed approach is validated by comparing predictions with the results of various examples published in the literature. Hence, this approach is shown to predict accurately the damping characteristics of arbitrarily shaped sandwich plates, with different material properties and boundary conditions, fully or partially covered with constrained viscoelastic layers. The influence of the damping patch locations and the viscoelastic material's shear modulus on the vibration and damping characteristics is investigated. To damp the plate effectively using partial coverage, the damping patches must be distributed appropriately. To select the best damping patch locations, an indicator based on the energy dissipated through the viscoelastic layer is proposed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The constrained-layer damping treatment is widely used to control the resonant response of vibrating structures, particularly in the automotive and aerospace industries. This technique requires design tools in order to select the best location, type and thickness of the damping and constraining-layer materials for optimum damping while minimizing the total weight of the damping treatments. In this study, a numerical tool is presented to analyze the vibration response of plates partially or fully covered with a constrained viscoelastic damping material. This tool is based on a finite element approach. The undamped plate structure is modeled using a discrete Kirchhoff theory (DKT) element. However, a sandwich plate element is specially derived to model the damped plate structure. This element is formulated in such a way that it is compatible with the DKT element. The natural frequencies and modal loss factors are derived from the modal strain energy method. The proposed approach is validated by comparing predictions with the results of various examples published in the literature. Hence, this approach is shown to predict accurately the damping characteristics of arbitrarily shaped sandwich plates, with different material properties and boundary conditions, fully or partially covered with constrained viscoelastic layers. The influence of the damping patch locations and the viscoelastic material's shear modulus on the vibration and damping characteristics is investigated. To damp the plate effectively using partial coverage, the damping patches must be distributed appropriately. To select the best damping patch locations, an indicator based on the energy dissipated through the viscoelastic layer is proposed. |
Laurence Fournaison; Anthony Delahaye; Salem Jerbi; Pascal Clain Etudes des cinétiques de formation des coulis d hydrates de CO2 et de leurs écoulements en présence d additifs Article de journal Dans: Revue Générale du Froid et du Conditionnement d air, (112), p. 50–56, 2011. @article{FDJC11, title = {Etudes des cinétiques de formation des coulis d hydrates de CO2 et de leurs écoulements en présence d additifs}, author = { Laurence Fournaison and Anthony Delahaye and Salem Jerbi and Pascal Clain}, url = {http://labs.esilv.fr/publications/public/2011/FDJC11}, year = {2011}, date = {2011-01-01}, journal = {Revue Générale du Froid et du Conditionnement d air}, number = {112}, pages = {50--56}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Nadia Mayoufi; Didier Dalmazzone; Anthony Delahaye; Pascal Clain; Laurence Fournaison; Walter Fürst Experimental Data on Phase Behavior of Simple Tetrabutylphosphonium Bromide (TBPB) and Mixed CO2 + TBPB Semiclathrate Hydrates Article de journal Dans: Journal of Chemical & Engineering Data, 56 (6), p. 2987–2993, 2011. @article{MDDCFF11, title = {Experimental Data on Phase Behavior of Simple Tetrabutylphosphonium Bromide (TBPB) and Mixed CO2 + TBPB Semiclathrate Hydrates}, author = { Nadia Mayoufi and Didier Dalmazzone and Anthony Delahaye and Pascal Clain and Laurence Fournaison and Walter Fürst}, url = {http://labs.esilv.fr/publications/public/2011/MDDCFF11}, year = {2011}, date = {2011-01-01}, journal = {Journal of Chemical & Engineering Data}, volume = {56}, number = {6}, pages = {2987--2993}, abstract = {The phase behavior of simple and mixed semiclathrate hydrates formed from CO2 + tetrabutylphosphonium bromide (TBPB) + water mixtures was investigated by pressure-controlled differential scanning calorimetry (DSC) at TBPB concentrations in the range of 0 to 0.073 mole fraction and at CO2 pressure in the range of (0 to 2.0) MPa. In a previous article we demonstrated that TBPB + CO2 mixed hydrates present high dissociation enthalpies and could be used as phase change material, covering the range of temperature from (284.6 to 289.0) K, for secondary refrigeration applications. The present work investigates a broader domain of compositions, resulting in x?T phase diagrams at atmospheric conditions and at various CO2 pressures. These data are required to model the potential latent heat of hydrate slurries as a function of gas pressure and aqueous phase composition over the whole range of interest for refrigeration purposes. The results presented show that adding TBPB to the water at low concentration (0.0058 mole fraction) decreases the pressure of formation of CO2 hydrates to 0.5 MPa at 281.6 K, instead of 3.5 MPa at the same temperature in the absence of a promoter. Crystallization of CO2 + TBPB hydrate could therefore offer an attractive means of capture for CO2.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The phase behavior of simple and mixed semiclathrate hydrates formed from CO2 + tetrabutylphosphonium bromide (TBPB) + water mixtures was investigated by pressure-controlled differential scanning calorimetry (DSC) at TBPB concentrations in the range of 0 to 0.073 mole fraction and at CO2 pressure in the range of (0 to 2.0) MPa. In a previous article we demonstrated that TBPB + CO2 mixed hydrates present high dissociation enthalpies and could be used as phase change material, covering the range of temperature from (284.6 to 289.0) K, for secondary refrigeration applications. The present work investigates a broader domain of compositions, resulting in x?T phase diagrams at atmospheric conditions and at various CO2 pressures. These data are required to model the potential latent heat of hydrate slurries as a function of gas pressure and aqueous phase composition over the whole range of interest for refrigeration purposes. The results presented show that adding TBPB to the water at low concentration (0.0058 mole fraction) decreases the pressure of formation of CO2 hydrates to 0.5 MPa at 281.6 K, instead of 3.5 MPa at the same temperature in the absence of a promoter. Crystallization of CO2 + TBPB hydrate could therefore offer an attractive means of capture for CO2. |
Laurent George; Pierre Courbin; Yves Sorel Job vs. portioned partitioning for the earliest deadline first semi-partitioned scheduling Article de journal Dans: Journal of Systems Architecture, 57 (5), p. 518-535, 2011. @article{GCS11, title = {Job vs. portioned partitioning for the earliest deadline first semi-partitioned scheduling}, author = { Laurent George and Pierre Courbin and Yves Sorel}, url = {http://labs.esilv.fr/publications/public/2011/GCS11}, year = {2011}, date = {2011-01-01}, journal = {Journal of Systems Architecture}, volume = {57}, number = {5}, pages = {518-535}, abstract = {In this paper, we focus on the semi-partitioned scheduling of sporadic tasks with constrained deadlines and identical processors. We study two cases of semi-partitioning: (i) the case where the worst case execution time (WCET) of a job can be portioned, each portion being executed on a dedicated processor, according to a static pattern of migration; (ii) the case where the jobs of a task are released on a processor, 1 time out of p, where p is an integer at most equal to the number of processors, according to a round-robin migration pattern. The first approach has been investigated in the state-of-the-art by migrating a job at its local deadline, computed from the deadline of the task it belongs to. We study several local deadline assignment heuristics (fair, based on processor utilization and based on the minimum acceptable local deadline for a job on a processor). In both cases, we propose feasibility conditions for the schedulability of sporadic tasks scheduled using earliest deadline first (EDF) semi-partitioned scheduling. We show that the load function used for global scheduling to establish the feasibility of sporadic task sets exhibits interesting properties in the semi-partitioning context. We carry out simulations to study the performance of the two approaches in terms of success rate and number of migrations, for platforms composed of four and eight processors. We compare the performance of these semi-partitioned heuristics with the performance of classical partitioned scheduling algorithms and with a global scheduling heuristic which is currently considered to have good performances.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this paper, we focus on the semi-partitioned scheduling of sporadic tasks with constrained deadlines and identical processors. We study two cases of semi-partitioning: (i) the case where the worst case execution time (WCET) of a job can be portioned, each portion being executed on a dedicated processor, according to a static pattern of migration; (ii) the case where the jobs of a task are released on a processor, 1 time out of p, where p is an integer at most equal to the number of processors, according to a round-robin migration pattern. The first approach has been investigated in the state-of-the-art by migrating a job at its local deadline, computed from the deadline of the task it belongs to. We study several local deadline assignment heuristics (fair, based on processor utilization and based on the minimum acceptable local deadline for a job on a processor). In both cases, we propose feasibility conditions for the schedulability of sporadic tasks scheduled using earliest deadline first (EDF) semi-partitioned scheduling. We show that the load function used for global scheduling to establish the feasibility of sporadic task sets exhibits interesting properties in the semi-partitioning context. We carry out simulations to study the performance of the two approaches in terms of success rate and number of migrations, for platforms composed of four and eight processors. We compare the performance of these semi-partitioned heuristics with the performance of classical partitioned scheduling algorithms and with a global scheduling heuristic which is currently considered to have good performances. |
Book Chapters |
Laurent George; Pierre Courbin Reconfiguration of Uniprocessor Sporadic Real-Time Systems: The Sensitivity Approach Book Chapter Dans: p. 167-189, IGI Global, 2011. @inbook{GC11, title = {Reconfiguration of Uniprocessor Sporadic Real-Time Systems: The Sensitivity Approach}, author = { Laurent George and Pierre Courbin}, url = {http://labs.esilv.fr/publications/public/2011/GC11}, year = {2011}, date = {2011-01-01}, pages = {167-189}, publisher = {IGI Global}, abstract = {In this chapter the authors focus on the problem of reconfiguring embedded real-time systems. Such reconfiguration can be decided either off-line to determine if a given application can be run on a different platform, while preserving the timeliness constraints imposed by the application, or on-line, where a reconfiguration should be done to adapt the system to the context of execution or to handle hardware or software faults. The task model considered in this chapter is the classical sporadic task model defined by a Worst Case Execution Time (WCET), a minimum inter-arrival time (also denoted the minimum Period) and a late termination deadline. The authors consider two preemptive scheduling strategies: Fixed Priority highest priority first (FP) and Earliest Deadline First (EDF). They propose a sensitivity analysis to handle reconfiguration issues. Sensitivity analysis aims at determining acceptable deviations from the specifications of a problem due to evolutions in system characteristics (reconfiguration or performance tuning). They present a state of the art for sensitivity analysis in the case of WCETs, Periods and Deadlines reconfigurations and study to what extent sensitivity analysis can be used to decide on the possibility of reconfiguring a system.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } In this chapter the authors focus on the problem of reconfiguring embedded real-time systems. Such reconfiguration can be decided either off-line to determine if a given application can be run on a different platform, while preserving the timeliness constraints imposed by the application, or on-line, where a reconfiguration should be done to adapt the system to the context of execution or to handle hardware or software faults. The task model considered in this chapter is the classical sporadic task model defined by a Worst Case Execution Time (WCET), a minimum inter-arrival time (also denoted the minimum Period) and a late termination deadline. The authors consider two preemptive scheduling strategies: Fixed Priority highest priority first (FP) and Earliest Deadline First (EDF). They propose a sensitivity analysis to handle reconfiguration issues. Sensitivity analysis aims at determining acceptable deviations from the specifications of a problem due to evolutions in system characteristics (reconfiguration or performance tuning). They present a state of the art for sensitivity analysis in the case of WCETs, Periods and Deadlines reconfigurations and study to what extent sensitivity analysis can be used to decide on the possibility of reconfiguring a system. |
inproceedings |
Pascal Clain; Anthony Delahaye; Laurence Fournaison; Salem Jerbi; Nadia Mayoufi; Didier Dalmazzone; Walter Fürst Characterization of mixed CO2 + TBPB hydrates for refrigeration applications Inproceedings Dans: International conference on gas hydrates, Edinburgh, Scotland, 2011. @inproceedings{CDFJMDF11, title = {Characterization of mixed CO2 + TBPB hydrates for refrigeration applications}, author = { Pascal Clain and Anthony Delahaye and Laurence Fournaison and Salem Jerbi and Nadia Mayoufi and Didier Dalmazzone and Walter Fürst}, url = {http://labs.esilv.fr/publications/public/2011/CDFJMDF11}, year = {2011}, date = {2011-01-01}, booktitle = {International conference on gas hydrates}, address = {Edinburgh, Scotland}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } |
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