RETRACTED : Elastic-plastic analysis of reinforced composite materials

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see : http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 25 June 202

Modeling dynamic systems : contribution to the unsteady behavior of a condenser based on the pseudo-bond graph approach

This article is devoted to the dynamic study of the brazed plate condenser (BPC). The proposed model is based on the bond graph theory. The proposed model is based on the bond graph theory because of its energetic approach and multi-physics character of the studied system. The model is discretized into five control volumes. The resolution of mass and energy equations is done by Runge-Kutta method embedded in 20sim software. Analyses of simulation results show that the model has a good ability to transcribe the time evolution of the temperature and pressure in both regimes, transitional and permanent. Also, the model is experimentally validated without any fitting of the set of thermal exchange coefficients.FUI Thermodluid-R

Experimental development and bond graph dynamic modelling of a brazed plate heat exchanger

This article is devoted to the dynamic study of a brazed plate heat exchanger (BPHE). First, an introduction to the industrial context of the current FUI THERMOFLUIDE project is proposed. A succinct presentation of the heat exchanger technology is proposed. Afterward, a state of the art discussion of BPHE modelling, heat transfer and pressure drop correlations is given. Then a detailed mathematical description of an original dynamic model is presented. The last section deals with a description of the experimental test rig and performed validation tests.FUI Thermodfluid-R

Development of a Model Based on Physical Mechanisms for the Explanation of Drug Release: Application to Diclofenac Release from Polyurethane Films

In this study, we present a method for prediction of the drug-release profile based on the physical mechanisms that can intervene in drug release from a drug-carrier. The application presented here incorporates the effects of drug concentration and Reynolds number defining the circulating flow in the testing vein. The experimental data used relate to the release of diclofenac from samples of non-degradable polyurethane subjected to static and continuous flow. This case includes simultaneously three mechanisms: burst-release, diffusion and osmotic pressure, identified beforehand here as being able to contribute to the drug liberation. For this purpose, authors coded the Sequential Quadratic Programming Algorithm to solve the problem of non-linear optimization. The experimental data used to develop the mathematical model obtained from release studies carried out in water solution at 37 °C, for three concentrations of diclofenac and two water flow rates. We discuss the contribution of mechanisms and kinetics by considering two aforementioned parameters and, following that, we obtain the specific-model and compare the calculated results with the experimental results for the reserved cases. The results showed that drug percentage mostly affect the burst release, however flow rate has affected the osmotic release. In addition, release kinetics of all the mechanisms have increased by increasing the values of two considered parameters

Finite Element and Neural Network Based Predictive Model to Determine Natural Frequency of Laminated Composite Plates with Eccentric Cutouts under Free Vibration

This research proposes a predictive model to identify changes in the mechanical and geometrical properties of composite plates with eccentric cutouts based on natural frequency. Finite elements (FE) and neural networks are used to develop the model based on machine learning. First, the numerical analysis of free vibration is performed by the FE model on the laminated composite plates with a stacking sequence [0/90]2s under a clamped-free (CFFF) boundary condition. The outputs of the FE model (520 configurations) are then utilized to train the artificial neural network (ANN) model through the Levenberg-Marquardt method, and the developed ANN model is then used to evaluate the influence of various parameters on the natural frequency. The results show that the changes in the mechanical and geometrical properties of composite plates have impacts on the natural frequency. Furthermore, the findings of the ANN model are substantially identical to those of the numerical model, with a small margin of error

Bond graph based modeling and experimental validation of a two-phase fluid loop mechanically pumped

Cette thèse s’inscrit dans le cadre du projet FUI THERMOFLUIDE-RT impliquant des Grands Groupes (Zodiac DS, Safran Hispano, MBDA), des PME (Atmostat, ADR, ControlSys) et cinq laboratoires (CRIStAL, LML Arts et Métiers Paris Tech, LEGI Grenoble, LMT ENS Cachan, CEA-Liten Grenoble). Le but est d’étudier un nouveau système de refroidissement de l’électronique. La technologie retenue est celle d’une boucle fluide diphasique à pompage mécanique (BFDPM). La thèse traite la modélisation dynamique et la validation expérimentale des composants de la boucle. Ceci permet de prévoir l’efficacité du système à partir de ses paramètres d’entrée, d’analyser les problèmes de régimes transitoires, et de proposer un outil de dimensionnement. La méthodologie bond graph est retenue à cause du caractère multi-physique des composants. D’abord, la problématique de base et le contexte sont présentés. Ceci permet d’introduire la solution retenue, celle des BFDPM. Les objectifs de la thèse sont décrits. Ensuite, une description du banc expérimental développé au cours de cette thèse est proposée. Les trois chapitres suivant sont consacrés à l’étude théorique et expérimentale des équipements de la boucle. Chacun de ces chapitres commence par l’état de l’art sur les travaux de modélisation et les corrélations des coefficients d’échange et des pertes de charge. Une seconde partie décrit les phénomènes et les équations. Une troisième partie est réservée à la validation des modèles. Un dernier chapitre récapitule les travaux de couplage des modèles dynamiques validés séparément. En conclusion, un récapitulatif des contributions est effectué. Des perspectives à court et moyen terme sont proposéesThis thesis is part of the collaborative project FUI THERMOFLUIDE-RT involving major groups (Zodiac DS, Safran Hispano, and MBDA), SMEs (Atmostat Alcen, ADR, AER, ControlSys) and five laboratories (CRIStAL Ecole Centrale de Lille, LML Arts et Métiers Paris Tech, LEGI Grenoble, LMT ENS Cachan, CEA-Liten Grenoble). The main purpose is to study a new electronic cooling system. The technology chosen consists of a two-phase fluid loop mechanically pumped (TPLMP). The thesis deals with the dynamic modeling and experimental validation of the cooling components. The developed dynamic model allows to predict the efficiency of the cooling loop, to conduct the study of transitional regimes, and provides an original tool dedicated to design the loop components. The bond graph methodology is adopted because of the multi physics character of the studied components. First, the basic issues and the industrial context are presented. This allows to introduce the chosen solution (TPLMP). The objectives of the thesis are described. Then, a description of the rig test is proposed. The following three chapters are devoted to a theoretical and experimental study of the loop equipment. Each chapter begins with a state of the art on modeling and correlations of the heat exchange coefficients and losses. A second part of the chapter describes phenomena and equations. A third part is dedicated to the experimental validation. A final chapter presents the coupling works of dynamic models validated separately. Finally, a summary of all contributions is made. Prospects for future developments in short and medium term are proposed

Modélisation dynamique basée sur l'approche bond graph d'une boucle fluide diphasique à pompage mécanique avec validation expérimentale

This thesis is part of the collaborative project FUI THERMOFLUIDE-RT involving major groups (Zodiac DS, Safran Hispano, and MBDA), SMEs (Atmostat Alcen, ADR, AER, ControlSys) and five laboratories (CRIStAL Ecole Centrale de Lille, LML Arts et Métiers Paris Tech, LEGI Grenoble, LMT ENS Cachan, CEA-Liten Grenoble). The main purpose is to study a new electronic cooling system. The technology chosen consists of a two-phase fluid loop mechanically pumped (TPLMP). The thesis deals with the dynamic modeling and experimental validation of the cooling components. The developed dynamic model allows to predict the efficiency of the cooling loop, to conduct the study of transitional regimes, and provides an original tool dedicated to design the loop components. The bond graph methodology is adopted because of the multi physics character of the studied components. First, the basic issues and the industrial context are presented. This allows to introduce the chosen solution (TPLMP). The objectives of the thesis are described. Then, a description of the rig test is proposed. The following three chapters are devoted to a theoretical and experimental study of the loop equipment. Each chapter begins with a state of the art on modeling and correlations of the heat exchange coefficients and losses. A second part of the chapter describes phenomena and equations. A third part is dedicated to the experimental validation. A final chapter presents the coupling works of dynamic models validated separately. Finally, a summary of all contributions is made. Prospects for future developments in short and medium term are proposed.Cette thèse s’inscrit dans le cadre du projet FUI THERMOFLUIDE-RT impliquant des Grands Groupes (Zodiac DS, Safran Hispano, MBDA), des PME (Atmostat, ADR, ControlSys) et cinq laboratoires (CRIStAL, LML Arts et Métiers Paris Tech, LEGI Grenoble, LMT ENS Cachan, CEA-Liten Grenoble). Le but est d’étudier un nouveau système de refroidissement de l’électronique. La technologie retenue est celle d’une boucle fluide diphasique à pompage mécanique (BFDPM). La thèse traite la modélisation dynamique et la validation expérimentale des composants de la boucle. Ceci permet de prévoir l’efficacité du système à partir de ses paramètres d’entrée, d’analyser les problèmes de régimes transitoires, et de proposer un outil de dimensionnement. La méthodologie bond graph est retenue à cause du caractère multi-physique des composants. D’abord, la problématique de base et le contexte sont présentés. Ceci permet d’introduire la solution retenue, celle des BFDPM. Les objectifs de la thèse sont décrits. Ensuite, une description du banc expérimental développé au cours de cette thèse est proposée. Les trois chapitres suivant sont consacrés à l’étude théorique et expérimentale des équipements de la boucle. Chacun de ces chapitres commence par l’état de l’art sur les travaux de modélisation et les corrélations des coefficients d’échange et des pertes de charge. Une seconde partie décrit les phénomènes et les équations. Une troisième partie est réservée à la validation des modèles. Un dernier chapitre récapitule les travaux de couplage des modèles dynamiques validés séparément. En conclusion, un récapitulatif des contributions est effectué. Des perspectives à court et moyen terme sont proposée

Modeling dynamic systems : contribution to the unsteady behavior of a condenser based on the pseudo-bond graph approach

International audienceThis article is devoted to the dynamic study of the brazed plate condenser (BPC). The proposed model is based on the bondgraph theory. The proposed model is based on the bond graph theory because of its energetic approach and multi-physicscharacter of the studied system. The model is discretized into five control volumes. The resolution of mass and energy equationsis done by Runge-Kutta method embedded in 20sim software. Analyses of simulation results show that the model has a goodability to transcribe the time evolution of the temperature and pressure in both regimes, transitional and permanent. Also, themodel is experimentally validated without any fitting of the set of thermal exchange coefficients