Tesi sul tema "Transfert de chaleur couplé"
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Bougeard, Daniel. "Etude expérimentale du transfert thermique couplé au sein de géométries complexes : application aux échangeurs de chaleur". Valenciennes, 1997. https://ged.uphf.fr/nuxeo/site/esupversions/32ad393b-fdf6-43c3-803f-5411e53c570f.
Oulaid, Othmane. "TRANSFERT COUPLÉ DE CHALEUR ET DE MASSE PAR CONVECTION MIXTE AVEC CHANGEMENT DE PHASE DANS UN CANAL". Phd thesis, Université de Sherbrooke, 2010. http://tel.archives-ouvertes.fr/tel-00669024.
Lazard, Myriam. "Modélisation macroscopique du transfert de chaleur transitoire couplé conduction rayonnement dans un milieu semi-transparent : estimation de paramètres". Vandoeuvre-les-Nancy, INPL, 2000. http://www.theses.fr/2000INPL030N.
Wu, Jing. "Modélisation dynamique d’un système couplé pompe à chaleur – stockage thermique par matériaux à changement de phase : approche systémique et validation expérimentale". Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10167/document.
In the area of buildings refrigeration, the use of thermal energy storage coupled with heat pump is a significant way for reducing the operating costs and optimizing the design of equipment. A prototype of refrigeration-PCM (Phase Change Material) energy storage system is built and implemented within the framework of the project ACLIRSYS (Advanced Control for Low Inertia Refrigeration Systems), funded by the French National Research Agency. The objective of my PhD thesis is to propose a dynamical physical model for the complete system. Within the evaporator and condenser of the heat pump, the refrigerant can be liquid, vapor or mixture of both, while the storage media can be solid, liquid or a mixture of both. Therefore, it is necessary to consider the discrete events associated to phase changes in order to solve the energy and mass balances in different configurations. In this work, static models are used for the compressor and the expansion valve of the heat pump. The heat exchangers of the heat pump and the storage models are based on a representation of the fluid flows by a cascade of Continuous Stirred Tank Reactors (CSTRs). In order to assure the continuity of system evolution, the switching mechanism between different configurations is established. This switching is performed by matrix operations, which permit to achieve a global and very compact representation of the system. The thermodynamic properties of the refrigerant and their partial derivatives are analytically determined by using an equation of state. Two versions of the model for the storage are proposed. A simplified version where the supercooling is assumed to take place at a constant temperature and a more detailed version based on the population balance equations. Experimental data from the prototype has been used to validate the developed model. Experiments in transient states were performed by varying the operating conditions. These date relate to the functioning of the heat pump alone, the storage alone and the coupled system. A very good agreement between the numerical results and experimental data was obtained
Draoui, Abdeslam. "Etudes numériques des transferts de chaleur couples rayonnement-conduction et rayonnement-convection dans un milieu semi-transparent bidimensionnel". Lyon, INSA, 1989. http://www.theses.fr/1989ISAL0012.
The works we present here are a numerical approach of heat transfer coupling radiation-conduction and radiation-convection within semi-transparent two-dimensional medium ; The first part deals with a view of equation of radiative transfer and introduces three numerical methods (P1, P2, Hottel's zone) which enable one to solve this problem in a two dimensional environment. After comparing the three methods in the case where radiation is the only mode of transfer, we introduce in the second chapter a study of the coupling of radiation with conduction. So, a fourth method is used to solve the problem. These comparisons lead us to various methods which enable us to show the interest of the spherical harmonics approximations. In the third part, the P1 approximations is kept because it is simple to use, moreover it enables us to introduce both the coupling of radiative transfers with laminar convective equations in a thermally driven two-dimensional cavity. The results show a significant influence of the radiative participation of the fluid on heat and dynamic transfer we met in this type of problem
Flores, Carolina. "Etude des transferts de masse et de chaleur au sein d'un absorbeur eau/bromure de lithium". Phd thesis, Université de Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-01062936.
Ramousse, Julien. "Transferts couplés masse-charge-chaleur dans une cellule de pile à combustible à membrane polymère". Vandoeuvre-les-Nancy, INPL, 2005. http://www.theses.fr/2005INPL098N.
Understanding and modelling of coupled mass, charges and heat transfers phenomena are fundamental to analyse the electrical behaviour of the system. The aim of the present model is to describe electrical performances of a PEFMC according to the fluidic and thermal operating conditions. The water content of the membrane and the water distribution in the single cell are estimated according to the coupled simulations of mass transport in the thickness of the single cell and in the feeding channels of the bipolar plates. A microscopic model of a Gas Diffusion Electrode is built up to describe charges transfer phenomena occurring at the electrodes. Completed by a study of heat transfer in the Membrane Electrode Assembly, conditions and preferential sites of water vapour condensation can be highlighted. A set of measurements of the effective thermal conductivity of carbon felts used in fuel cells as porous backing layers have also been performed. Although the value of this parameter is essential for the study of heat transfer, it is still under investigation because of the strong thermal anisotropy of the medium
Chehbouni, Abdelghani. "Présentation d'un modèle de transfert couplé de masse et de chaleur dans le système sol-végétation-atmosphère pour les zones arides et semi-arides". Toulouse 3, 1992. http://www.theses.fr/1992TOU30083.
Delarochelambert, Thierry. "Etude expérimentale et théorique des transferts thermiques couples en convection naturelle à travers une double paroi verticale à haute densité de flux de chaleur". Mulhouse, 1997. http://www.theses.fr/1997MULH0506.
Aklouche, Leila. "Modélisation des transferts couplés masse-chaleur dans un matériau amylacé lors des hydrotraitements par haute pression : caractérisations physicochimiques et thermophysiques". Thesis, La Rochelle, 2019. http://www.theses.fr/2019LAROS025.
This thesis aims on the one hand to understand the physical changes generated in the internal structure of a biopolymer material submitted to high-pressure hydrotreatments and on the other hand to the modelling of coupled heat and mass transfers. In this work, standard maize starch was chosen as a model material and four processes were investigated; DV-HMT (Direct Vapor-Heat Moisture Treatment), RP-HMT (Reduced Pressurized-HMT), IV-HMT (Intensive Vacuum-HMT) et FV-HMT (Final Vacuum-HMT). As the progression of biochemical reactions is strongly affected by the temperature and water content that alter the physical and thermophysical properties of the reactive material, their prediction is very important. The analysis of phase transitions and structure, related to the involved phenomena (cristallites fusion, formation of amylose-lipids complexes, retrogradation) was performed by calorimetry, X-ray diffraction and by FTIR spectroscopy. The transfers modelling has been advanced by an experimental and theoretical approaches. In the experimental approach, the physical (apparent density, bulk density and porosity) and thermophysical properties (specific heat, conductivity ant thermal diffusivity) were measured by considering the variation of W, T and the crystallites fusion phenomenon. Empirical models expressing these properties have been determined and the values implemented in the transfer equations. In the theoretical approach, the coupled equations of the transfer model were discretised by the finite element method and resolved by COMSOL Multiphysics®. The numerical resolution allowed the prediction of the spatial repartition of variable parameters (T, W, ξ, λ, Cp,...) according to treatment time. The curves of ξ numerically simulated by COMSOL® go through all experimental values, thus validating the theoretical models
Kavazovic, Zanin. "Modélisation mathématique du pressage à chaud des panneaux MDF. Couplage du modèle mécanique avec le modèle couplé de transfert de chaleur et de masse". Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27946/27946.pdf.
Kavazović, Zanin. "Modélisation mathématique du pressage à chaud des panneaux MDF : couplage du modèle mécanique avec le modèle couplé de transfert de chaleur et de masse". Doctoral thesis, Université Laval, 2011. http://hdl.handle.net/20.500.11794/22585.
Challansonnex, Arnaud. "Transferts couplés chaleur/masse dans les matériaux de construction biosourcés : investigation expérimentale et théorique du non-équilibre local". Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLC022/document.
The growing interest in biosourced materials in the construction sector is confronted with difficulties in simulating their hygrothermal behavior. Insulating materials such as fiberboard concentrate all the difficulties because they are not very thermally conductive, very hygroscopic and very diffusive to water vapor. Consequently, in transient state, heat and mass coupling is exacerbated, and the phases of water are not in equilibrium locally.In order to highlight this second phenomenon, a new experimental device has been developed. It allows to subject a sample a few centimeters thick to a disturbance of relative humidity on its front face and then to simultaneously measure the evolution of relative humidity on its back face and its mass. In a situation of non-equilibrium, there is a phase shift between these two quantities that the classic coupled transfer formulation cannot predict. In order to obtain a correct prediction, a new formulation was used. It is based on the use of memory functions characterizing microscopic diffusion. In order to demonstrate the predictive capacity of the new formulation, these functions have been determined with gravimetric tests performed on very small samples using a magnetic suspension balance. In parallel, a rigorous analysis of the heat and mass coupling in these materials made it possible to highlight the impact of different macroscopic parameters on their characterization.The use of the new formulation fed by the identified memory functions and the various macroscopic parameters allows an excellent prediction of relative humidity and mass. This new formulation, experimentally validated, can now be used in energy simulation of the building
Amraqui, Samir. "Modélisation des transferts thermiques couplés dans un capteur solaire thermique avec cellules anti-pertes". Aix-Marseille 1, 2009. http://www.theses.fr/2009AIX11033.
Following the report of the important climate changes worldwide, many actions are carried out for renewable energies development and in particular of solar energy. Various technological solutions have thus been introduced such as the solar collector equipped with cells decreasing losses whose principle is to allow the improvement of the ratio « production of heat / investment » by recuperation of the thermal energy that they dissipate using coolant. It is in this context that this thesis is carried out. This framework is based on the numerical simulation of the natural convection combined to the radiation heat transfer in a solar collector equipped with partitions attached to its glazing. Three different solar collector configurations were considered: case (A) the solar collector is placed in a gravity acceleration whose direction is perpendicular to the temperature gradient, (b) the solar collector is placed perpendicular to the gravity acceleration and (c) the solar collector is tilted of 45° from horizontal. The considered coolant is the dry air (Pr = 0. 71) and its physical properties are supposed constant at the average temperature T0, except its density. Moreover, it is assumed to be incompressible, laminar, two dimensional and radiative surfaces are supposed to be gray and isotropic in emission / reflection. The numerical methodology used for the resolution of the differential equations controlling the heat transfer and the flow in the studied systems is using the finite volume method. The coupling pressure - velocity problem is treated by the SIMPLER algorithm and the algebraic systems obtained are solved by a conjugate gradient method. In this thesis, the convective flow is governed by various control parameters, namely the Rayleigh number Ra, partition length LP, partition thickness tP, partitions number NP, aspect ratio A and the inclination angle compared to horizontal j. Concerning the computer code validation, the agreement obtained between our results and those available in the literature proved to be excellent. The effect of the physical and geometrical parameters is examined. The results are presented in terms of isotherms, streamlines, average Nusselt number and dimensionless convective and radiative heat flow
Brige, Xavier. "Transferts de chaleur couplés par conduction et rayonnement dans les milieux semi-transparents anisotropes et non gris : Etude et comparaison des modèles en 1D". Nancy 1, 2005. http://www.theses.fr/2005NAN10195.
Bennani, Nassira. "Performances des cycles à absorption fonctionnant avec le couple eau-glycérol". Toulouse, INPT, 1986. http://www.theses.fr/1986INPT003G.
Bouyssier, Julien. "Transports couplés en géométries complexes". Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1929/.
This work interest is about stationary transfer and non-stationary transport by convection-diffusion onto complex geometries. For transport issues, complex refers to convection into flattened cavity of arbitrary transverse shape, slowly varying along the longitudinal direction. In the context of transfer, complex refers to non-axisymmetric domains of arbitrary transverse shape along which one or several parallel tubes convect heat or mass. For the transfer problem, this work extends the principle, validates the use, and illustrates the efficiency of Graetz modes decompositions for exchanges prediction in realistic exchangers configurations. This decomposition permits to formulate the initial 3D problem as a generalysed 2D eigenvalue problem, the numerical evaluation of which is drastically reduced. We generalyze Graetz modes solutions for arbitrary applied lateral boundary conditions. In the particular case of balanced exchangers, we bring to the fore a new neutral mode whose longitudinal variations are linear as opposed to classical Graetz modes displaying exponential decay. The numerical computation of those modes for semi-infinite configurations with lateral periodic boundary conditions shows that a few number of those provides a very good approximation for exchanges. In the case of finite exchangers coupled with inlet/oulet tubes, we show how to evaluate the amplitudes of Graetz modes in the various domains (inlet, exchanger, outlet) from functional minimization associated with input/output boundary conditions. The evaluation of these amplitudes permit a systematic parametric study of temperature fields, heat fluxes between fluid and solid, and hot/cold performance of a couple-tube exchanger. Our results indicate that the typical exchange length is governed by the first Graetz mode at large P\'eclet number. We also show that a symmetric exchanger has a symmetric spectrum and a upward/backward symmetric evolution. In the case transport we elaborate theoretically the conservative form of 3D Taylor dispersion equations into variable cavities which generalyzes the framework already known in 2D. We numerically implement these averaged dispersion equations with finite element, and validate in 2D the obtained results. We show that 3D longitudinal variations of a cavity has a strong impact on the longitudinal dispersion
Cherkaoui, Moha. "Modélisation et étude de sensibilité des échanges radiatifs et conductifs couplés dans une cavité remplie d'air ambiant". Paris 12, 1993. http://www.theses.fr/1993PA120037.
Guillot, Émilien. "Étude expérimentale des transferts de chaleur à une interface pièce-outil de coupe". Nantes, 2009. http://www.theses.fr/2009NANT2005.
The study relates to the characterization of the interface of contact sliding piece-tool under great deformations representative of the secondary shear zone of a HSM process. The literature shows that the authors consider a perfect thermal contact condition and suppose that the heat flux generated by friction is divided in the ratio of the thermal effusivities of materials in contact. However the distribution of the strain at this interface is huge and the thermal contact must become poor before the release of the chip. The goal of the thesis is to propose an experimental methodology (founded to the measure of the temperature field by thermocouples and its analysis by inverse technique) in order to determine the contact parameters describing a sliding contact seat of a heat dissipation : α , Rtc et φg The measurement principle presents an original approach which treats in a sequential way and by subdomain the zones on both sides of the interface. The thermal conditions which prevail on the contact surfaces are estimated singly. Then, generated heat flux (φg ) and in a simultaneous way α and Rtc et φg are estimated. We have studied the instrumentation by thermocouples in order to control the compromise sensitivity/precision and to well understand the intrusive character of thermocouples set up. Experiments were carried out on friction device that reproduces the mechanics and thermals contact conditions of a HSM process at the tip tool. The experimental plan allows to study the influence the sliding speed and the nature of the tribological couple on the thermal parameters of contact
Dardour, Béchir. "Étude des transferts thermiques couples dans une plaque de cuisson vitrocéramique infrarouge". ENSMP, 1999. http://www.theses.fr/1999ENMP0892.
Moyne, Christian. "Transferts couples chaleur-masse lors du séchage : prise en compte du mouvement de la phase gazeuse". Vandoeuvre-les-Nancy, INPL, 1987. http://www.theses.fr/1987NAN10348.
Guillemant, Philippe. "Modélisation numérique et analytique des transferts couplés rayonnement-conduction dans les milieux semi-transparents : identification expérimentale par la méthode de l'hémisphère". Aix-Marseille 1, 1992. http://www.theses.fr/1992AIX11038.
Mabsate, El-Mostafa. "Etude numérique 2D des transferts couplés de chaleur et de masse dans les milieux poreux non saturés : thermomigration avec effet de la gravité et infiltration non isotherme dans une cavité fermée". Paris 6, 1987. http://www.theses.fr/1987PA066743.
Bouallou, Chakib. "Modélisation bidimensionnelle des transferts couples rayonnement - convection naturelle dans les milieux semi-transparents". Lyon, INSA, 1989. http://www.theses.fr/1989ISAL0061.
This work includes four parts. In the first part, we explain the formulation of relative transfer in a semitransparent media. A comparative study for several calculation methods for the radiative equation is proposed. The P1 approximation in a two-dimensional form is them retained for modelling heat transfer coupled by radiation and convection. In the second one, we analyse the interaction between thermal radiation and natural convection within a two-dimensional porous medium. The radiative model is associated with a finite difference scheme which allows to solve convective equations described by Darcy's law and Boussinesq approximation. The study of dimensionless parameters which govern this interaction provides a better understanding of roles played by each mechanism of transfer. In the third part, the interaction between natural convection and thermal radiation in two-dimensional semi-transparent fluid has been investigated. Before analysing the case of non-grey medium we expose a parametric study for a grey fluid isotropic scattering. The last part deals with a much more difficult coupled problem. We consider the interaction between natural convection and thermal radiation within a cavity partially filled with a porous medium. For the interface, which is permeable and non-opaque, a radiative boundary condition is proposed. The convective equation are treated with combined Navier-Stokes and Brinkman equations. The effect of main parameters has been studied. It is shown that the permeable and non-opaque interface induces a deep modification in both thermal and dynamic fields
Khourchafi, Abdelhak. "Etude de l'approximation P1 pour les transferts radiatifs spectralement corrélés dans des gaz : application à l'étude des transferts couplés convection-rayonnement dans des échangeurs de chaleur à haute température". Châtenay-Malabry, Ecole centrale de Paris, 1994. http://www.theses.fr/1994ECAP0346.
Chassagne, Pierre. "Contribution à la prédiction des conséquences mécaniques des phénomènes thermo-hydriques couplés". Lyon, INSA, 2006. http://theses.insa-lyon.fr/publication/2006ISAL0069/these.pdf.
The effects of variable climatic conditions, combined to a mechanical loading, lead in some materials to delayed accumulations of stresses and strains. Recent advances in mechanics aims at bringing a better comprehension of the material behaviour, and to develop mathematical laws capable of integrating coupled multiphysics mechanisms. The main aim of this work consists in developing a numerical tool capable of bringing a contribution for the prediction of the mechanical behaviour for a complex material such as wood, in order to optimize the use, the service and forming, manufacturing or assembly processes. The first part is a state of the art of the knowledge on wood physics and mechanical behaviour. A reminder of the main notions on its hygroscopic characteristics is essential for a good understanding of the various phenomena developing in the material. Many macroscopic numerical models developed these last two decades allow us to bring important features for the comprehension of the mechanical behaviour of wood and the associated heat and mass transfer phenomena. These tools have mainly been developed for the study of mechanosorptive phenomena occurring in the longitudinal direction or in the transverse directions. The second part deals with the development of a 3D thermo-hydro-viscoelastic orthotropic numerical tool taking into account the different parameters controlling the material response (hygroscopic variation rate, history of these variations, equivalent stress level according to a 3D criterion). The model is based on two modules partially coupled. Finally, in the third part, the numerical tools developed in this work are evaluated. The evaluation of the mechanosorptive parameters of the model is based on various applications
Le, Courtois Véronique. "Evaporation d'une coupe méthacrylique en film mince mécaniquement agité". Vandoeuvre-les-Nancy, INPL, 1989. http://www.theses.fr/1989NAN10023.
Aghahadi, Mohammad. "Etude expérimentale et modélisation physique des transferts couplés chaleur-humidité dans un isolant bio-sourcé". Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCA007/document.
The conventional heat transfer models are not sufficiently suitable for thermal characterization of bio-sourced thermal insulating materials due to their strongly hydrophilic nature. The proposed work in this PhD thesis aims to answer this problem with experimental and theoretical approaches of coupled heat-moisture transfers. In the experimental approach, a thermal insulating material based on Flax Fiber Felt (FFF) is developed and then characterized at different hygrometric conditions with an asymmetric hot plate device. The humidity diffusion characterization of the samples is done using the GAB, GDW and Park theoretical moisture adsorption isotherm models. In the theoretical approach, a physical model of heat and mass transfer is proposed. It is solved numerically, in transient 3D configuration, by the finite element method under COMSOL Multiphysics and, in transient 1D configuration, by the finite difference method under MATLAB. The Levenberg-Marquardt method coupled with the 1D transient direct model and the measured temperatures made it possible to estimate the apparent thermal conductivity of the studied sample with a relative error of less than 6% compared to the experimental measurements, thus validating the theoretical models
Da, Silva Zaqueu Ernesto. "Transferts couples conduction / Rayonnement : Application de la méthode flash aux milieux semi-transparents". Lyon, INSA, 1997. http://www.theses.fr/1997ISAL0061.
The purpose of this work is to study the combined conduction-radiation heat transfer and to estimate, eventually the thermal properties of a semi-transparent medium using the flash method. A model based on the discrete ordinate method has been developed to solve the radiative transfer equation (RTE) under an integral form. Geometries under study are cylindrical (2D) and rectangular (ID). There is a good agreement between predicted incident radiation and radiative and results from published in literature. Test results indicate that the method is capable of taking into account absorption, emission scattering mechanisms and is applicable to combined energy modes. This method aimed to solve the RTE is then used to calculate the radiative parameters which are present in the energy equation. The semitransparent sample is submitted to a brief thermal impulsion on its top bounding surface, and the bottom bounding surface temperature evolution is determined through the model. Several numerical simulations for a cylindrical (2D) enclosure are performed. Results indicate that the bottom bounding temperature is not sensitive to radial heat transfers provided that the aspect ratio (r/e) is greater than about 4. A sensibility study to parameters which involved in the temperature evolution was realized. The analysis of the sensibility coefficient provides information about the feasibility of the estimation of the radiative and thermal properties but also indicates which parameters may be identified in that conditions. The artificial data used as input far the numerical simulation is computed temperature profile based on theoretical radiative and thermal properties plus noise. The LEVEMBERG-MARQUARDT method is used to perform nonlinear least-squares fits. The thermal diffusivity of a silica glass and of a ZnS glass have been identified using the proposed method
Maalouf, Mirti Naim. "Transferts thermiques couples dans un milieu fibreux soumis à une réaction de combustion catalytique". Lyon, INSA, 1991. http://www.theses.fr/1991ISALA066.
The catalytic combustion in a fibrous media increase the heat transfer by the way of the radiative transfer. The emissivity of a semi-trans parent media is higher then that of gas flame. Also, we have less pollutants emissions than. A classical combustion. Three modes of heat transfer in this material are considered : the conduction, the convection, the radiation transfer. Two concepts are use the equivalent media and the two phases media. The first concept consider that we have the temperature for the fluid and the solid. The second concept considers that we different temperatures for the fluid and the solid. The radiative transfer in a media considered as semi-transparent, grey, absorbent and diffusive described by a numerical method (Pl). The thermal energy is represented by a kinetic equation depending on components diffusion. Many boundaries conditions are considered which can simulate a grid at the entry of the catalytic media. To compare the different models results, many measurements are done. The temperature measured for different working conditions and for two types of burners. The testing stand allow also to follow in continuous the evaluation of the tenor of the combustion gas
Roustan, Hervé. "Modélisation des transferts couples de charge et de chaleur dans un électrolyseur industriel de production de fluor". Grenoble INPG, 1998. http://www.theses.fr/1998INPG0079.
Woloszyn, Monika. "Modélisation hygro-thermo-aéraulique des bâtiments multizones : proposition d'une stratégie de résolution du système couple". Lyon, INSA, 1999. http://www.theses.fr/1999ISAL0089.
In the analysis of the two criteria necessary for the thermal design of buildings - user's comfort and energy efficiency - air moisture content is an important factor. However, in most existing computer software, the evolution of moisture content is either neglected or represented in a very simplified way. This is partly due to convergence difficulties met during numerical resolution of coupled systems. Therefore, in this work, we contribute to the development of comprehensive and reliable modular simulation tools. The aim is to represent moisture-energy-airflow dynamic behaviour of a multizone building. Four substantial aspects are covered (l) airborne moisture transport, (2) vapour condensation, (3) vapour absorption by hygroscopic materials (4) vapour production. We propose an integrated model, representing moisture interaction with energy and airflow. A comparison with experimental results confirms that the proposed representation includes all elements necessary for a correct modeling of moisture propagation in a partitioned space. In Order to en sure a reliable numerical resolution of the proposed mode!, we examine the performances of different methods for solving systems of algebraic non-linear equations. As classical algorithms fail on our problem, we develop an iterative strategy based on black decomposition. Identified blacks correspond to principal physical systems: (1) airflow black: inter-zonal air movements, (2) energy black: temperatures in each zone, (3) moisture black: air moisture content in each zone. During the iterations, the values of variables are updated according to physical interaction among systems. During its validation on a set of benchmark tests designed by software users, the proposed strategy demonstrates its numerical reliability and adaptation to moisture-energy-airflow problems
Labat, Matthieu. "Chaleur - Humidité - Air dans les maisons à ossature bois : Expérimentation et modélisation". Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00790809.
Wang, Chengan. "Contribution à la simulation numérique des problèmes de transferts thermiques couplés par rayonnement et convection dans un milieu semi-transparent confiné dans une enceinte de géométrie complexe par une méthode de type meshless". Poitiers, 2011. http://www.theses.fr/2011POIT2317.
In this work, a meshless method is developed to solve radiative transfer problems and coupled transfer problems (radiation-conduction and radiation-convection) occuring in a semitransparent medium enclosed in a cavity of complex shape. The method is first used to solve the radiative transfer equation (RTE) by using the discrete ordinates framework. Three different formulations of the RTE are considered (first order formulation with the intensity as depend variable and two second order formulations with secondary variables). Several examples are treated in two dimensional and three dimensional geometries in order to assess the accuracy of the method. Next we have extended the application of the method to radiation-conduction coupled problems in steady state (the medium being homogeneous or heterogeneous by allowing the refractive index to vary spatially) and in unsteady state. In the second part of the thesis, we have shown how to solve three dimensional natural convection problems by using the vorticity and vector potential formulation. Finally, the application of this method to solve coupled radiation-convection problems is presented
Dubernard, Alexis. "Instrumentation pour la séparation des transferts thermiques couplés à la surface d'un paroi : application à la gestion d'ambiances". Artois, 2000. http://www.theses.fr/2000ARTO0202.
This work is within the framework of the experimental context of the separation and the measurement of the thermal transfers by radiation and convection. More particularly, we are interested in the energy interactions between a building wall, whether it is interior or an external one, and its micro-climatic environment. The solution planned to deal with this problem, rests on the use of an original instrumentation allowing the measurement of heat fluxes. A new sensor sensitive to the thermal radiations was characterized. That imposes the design of a calibration bank, the search of the best adapted definition fot its sensitivity, and the study of the effect of possible disturbances on its answer. The needs as well as possible for ensuring the comfort of the occupants in a room, while optimizing the energy management, impose the use of reliable devices and easily brought into operation. Our work then proposes the use of fluxmetric sensors, and in particular of the radiative one, for the optimal control of environments. Experimental results in managements of thermal environments of comfort, based on the concept of resultant temperature, are presented, and compared with a traditional regulation by air temperature. They show the advantages of the concept of flow applied to the regulation. Lastly, the problem of the separation of surface heat exchange between an external wall and its micro-climatic environment was approched within the framework of a first approach primarily experimental. We show that, by, the use of fluxmetric measurements, the determination of the exchanges coefficients and the decomposition of the solar contributions are made possible on the surface of a building wall
Konduru, Raj Narayan. "Coupled Conduction-Convection-Radiation heat transfer using Mesh-less methods : Application to porous heat exchanger". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0190.
This research concentrates on heat recovery in industries operating at high temperatures, such as metallurgy, iron and steel, cement, and glass production, with the goal of mitigating greenhouse gas emissions. An effective approach involves incorporating a porous structure within the heat exchanger to enhance heat transfer rates while minimizing pressure drops. Initially, experiments were conducted using porous heat exchangers with Kelvin cell foam structures. The experimental setup involved placing the foam inside a tube and subjecting it to high temperatures of up to SI{800}{degreeCelsius} radially, while air was flown axially. This arrangement encompassed the physical phenomena of coupled conduction, convection, and radiation. The results of these experiments were subsequently employed to validate a numerical model utilizing a deterministic approach, forming the foundational step of the project. However, these methods encountered challenges in conducting comprehensive analyses, considering various foam types, distinct geometric properties, and thermophysical material attributes that influence heat exchanger performance due to the intricate structure. Moreover, the interplay of conduction, convection, and radiation along with complex foam structures demanded substantial computational resources. Consequently, an alternative to the deterministic method (DM) was sought, leading to the exploration of mesh-free methods. The validated DM numerical model serves as a reference for the alternative models, with two models being adopted/developed. The first model, known as Semi Meshless Method (SMM) or DM-MCM, merges the deterministic approach with the statistical Monte Carlo Method. In this model, the deterministic approach efficiently calculates velocity fields, while the Monte Carlo method determines local temperature distributions. This combination proves effective and robust for complex geometries. Nevertheless, the first model retains a limitation in calculating flow fields using the deterministic approach, prompting the design of a second innovative model. The second model, referred to as SPH-MCM, utilizes smoothed particle hydrodynamics (SPH) to overcome the limitations of grid-based approximations when computing flow fields. SPH eliminates the need for a complicated mesh, facilitating more efficient velocity field calculations. These fields are then employed to compute temperature distributions using the Monte Carlo method. The primary advantage of this model lies in its reliance on a surface mesh and points, instead of solid geometries and a volume mesh. However, the SPH method requires a longer computation time compared to the deterministic approach. Both alternative models exhibit a high level of agreement with the deterministic model, highlighting their potential to advance heat exchanger design. The first model is employed for a comprehensive parametric analysis aimed at studying the power extracted and pressure drop for different porous structure's in the heat exchanger configuration
Dauvois, Yann. "Modélisation du transfert thermique couplé conductif et radiatif au sein de milieux fibreux portés à haute température". Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLC097/document.
In the present work, the effective heat transfer properties of fibrous medium are determined by taking into account a coupling of heat conduction and radiation. A virtual, statistically homogeneous, two-phase fibrous sample has been built by stacking finite absorbing cylinders in vaccum. These cylinders are dispersed according to prescribed distribution functions defining the cylinder positions and orientations. Cylinder overlappings are allowed. Extinction, absorption and scattering are characterised by radiative statistical functions which allow the Beerian behaviour of a medium to be assessed (or not). They are accurately determined with a Monte Carlo method. Whereas the gaseous phase exhibits a Beerian behaviour, the fibre phase is strongly non Beerian. The radiative power field deposited within the fibrous material is calculated by resolving a model which couples a Generalized Radiative Transfer Equation (GRTE) and a classic Radiative Transfer Equation (RTE). The model of conduction transfer is based on a random walk method without meshing. The simulation of Brownian motion of walkers in fibres allows the energy equation to be solved. The idea of the method is to characterize the temperature in an elementary volume by the density of walkers, which roam the medium. The problem is governed by boundary conditions ; A constant concentration of walkers (or a constant flux) is associated with a fixed temperature (or flux)
Menigault, Thierry. "Etude des transferts de chaleur couples dans un lit poreux bicouche sélectif chaud : application à la conversion de l'énergie solaire concentrée". Perpignan, 1992. http://www.theses.fr/1995PERP0198.
Villière, Maxime. "Analyse des transferts de chaleur couplés à la saturation pendant l’imprégnation d’un renfort fibreux : application aux procédés LCM". Nantes, 2013. http://archive.bu.univ-nantes.fr/pollux/show.action?id=30bc4fa5-7b2e-407e-a4eb-83977ffd0527.
Transportation industries, especially aeronautics and automotive industries, are facing more than ever energy-saving issues, which imply weight reduction of structures. Within this context, composite materials appear to be appropriate candidates, due to their outstanding “strength to weight” ratio. Liquid Composite Molding (LCM) and particularly Resin Transfer Molding (RTM) are becoming increasingly important for a wide range of industrial applications involving complex structural parts. The quality of LCM products strongly depends on the impregnation of the fiber preform during the mold-filling stage. During this step, a partially saturated zone emerges in the flow, and induces consequently the formation of porosities, which drastically affect mechanical performances. This study presents an original approach in which heat transfers are used to quantify the saturation profile. In a first step, the effective thermal conductivity of a model composite material have been measured by several methods. A homogenization methodology based on asymptotic expansion has been performed at dual-scale in order to predict the thermal properties of the composite as a function of saturation. Several heat flux sensors and thermocouples were integrated in an experimental bench, which allows the injection of a model fluid into a textile preform. Finally, an alternative numerical approach is proposed by modeling a multi-phase flow, proving the feasibility of identifying the relative permeabilities of each phase through thermal analysis
Lock, Nancy. "Modélisation numérique par éléments finis des transferts couplés sur une frontière mobile". Aix-Marseille 1, 1997. http://www.theses.fr/1997AIX11015.
M'Hamdi, Mohammed. "Modélisation de la solidification en coulée continue de l'acier". Vandoeuvre-les-Nancy, INPL, 1999. http://www.theses.fr/1999INPL102N.
Amri, Boudjemaa. "Contribution à l’étude du comportement des matériaux modernes pour les outils coupants". Lyon, INSA, 1988. http://www.theses.fr/1987ISAL0069.
Andrade, Molenda Carlos Henrique de. "Influence des effets d'hysteresis sur les phénomènes de transferts couplés de chaleur et masse en milieux poreux". Toulouse, INPT, 1991. http://www.theses.fr/1991INPT066H.
Semnani, Rahbar Mojtaba. "Nouvelles frigo-pompes et thermo-frigo-pompes à absorption pour production simultanée du chaud et du froid : nouveaux couples : solutions idéales d'hydrocarbures. Nouvelles structures à film ruisselant sur tubes à ailettes spiralées". Vandoeuvre-les-Nancy, INPL, 1994. http://www.theses.fr/1994INPL089N.
Ferrani, Farid. "Calculs couplés de transferts thermiques et de réactions physico-chimiques : application à l'encrassement des échangeurs". Paris 6, 1986. http://www.theses.fr/1986PA066110.
Leroy, Vincent. "Modélisation des couplages entre des transferts conductifs, convectifs et radiatifs en milieux poreux". Phd thesis, Ecole Centrale Paris, 2013. http://tel.archives-ouvertes.fr/tel-00825130.
El, Ammouri Fouad. "Etude théorique des transferts couplés conductif, convectif et radiatif dans des écoulements gazeux hétérogènes et turbulents : mesure du flux conductif par déviation de faisceau laser". Châtenay-Malabry, Ecole centrale de Paris, 1993. http://www.theses.fr/1993ECAP0310.
Muller, Jean-Damien. "Etude des changements de phase de polymère dans le procédé de rotomoulage : coalescence et cristallisation couplées à la thermique du procédé". Lyon, INSA, 2008. http://theses.insa-lyon.fr/publication/2008ISAL0069/these.pdf.
Rotomolding is a process of plastic forming which can produce hollow and high volume parts without weld line. Phase changements during the process determine the final quality of the part. The lack of modelling of the process limits its development. This thesis is divided in 2 parts: the first deals with understanding and modelling of the coalescence of polymer materials; the second part will present work on understanding the powder flow during the rotomolding and modelling thermal process. During the heat phase the coalescence is a perponderant phenomenon whose kinetics depend on the material used. A study with model materials, liquid at room temperature, made it possible to determine the parameters governing manily the sintering kinetics. The influence of these parameters was also tested with industrial materials. The powder flow of a polymer during the rotomolding has been studied with a mold with a transparent face. In addition it was possible to observe the different phases taking place in particular during the heating phase (the accession of powder and progressive fusion). To understand and be able to model the thermal exchanges during the rotomolding, a study was conducted in collaboration with the Laboratoire de Thermocinétique of Nantes. The measure temperatures at different points in the mould and the heat flow were carried out in situ during a cycle. The predicted temperature profile during the cooling phase has been described by coupling the heat and a model of crystallization kinetic
Zarea, Mures Florin. "Déstratification d'un stockage par court-circuit thermique". Châtenay-Malabry, Ecole centrale de Paris, 1991. http://www.theses.fr/1991ECAP0217.
Abahri, Kamilia. "Modélisation des transferts couplés de chaleur, d'air et d'humidité dans les matériaux poreux de construction". Thesis, La Rochelle, 2012. http://www.theses.fr/2012LAROS384.
The purpose of this thesis is to study coupled heat air and moisture transfer in porous building materials. Concerning the modeling part, the interest is to predict the hygrothermal behavior, with a macroscopic model, that incorporates simultaneously the effect of thermodiffusion phenomenon and that of total pressure on the building walls. The input parameters are evaluated experimentally using continuous driving potentials, where the ability to deal with problems of transfer in multilayer materials. In some configurations, it presents the advantage to undertake analytical solution that can be confronted with numerical solutions. Furthermore, a formal justification of balance equations of the developed model was addressed through the use of ascaling approach. Then, the modeling of macroscopic moisture transfer behavior, by implementing information from the microstructure can be refined. The transition of the microscopic to macroscopic scale was performed using the mean field homogenization. One of the difficulties with the use of this model lies in the identification of many parameters characterizing the hygrothermal properties of materials. Therefore, a part of the present work was devoted to the evaluation of the main properties of materials through the development of various experimental prototypes in the laboratory. More over, an experimental approach dedicated to the evaluation of the thermodiffusion process in porous materials has been undertaken. In this way, an experimentation concerning the determination of the temperature gradient and dynamics of water exchange process inside walls has been established. Furthermore, the use of the experimental platform MegaCup at theTechnical University of Denmark has collected data on the sensitivity of the thermodiffusion effect. Subsequently, a comparison of the experimental and the numerical results was performed. Few differences were observed. Otherwise, an experimental investigation on the contribution of the mass infiltration of water transfers in building materials was performed. A characterization of the moisture infiltration coefficient was performed through the development of the experimental test. This coefficient was used as an input parameter in the simulation models