Dissertations / Theses on the topic 'Fluides caloporteurs – Propriétés thermiques'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 29 dissertations / theses for your research on the topic 'Fluides caloporteurs – Propriétés thermiques.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Nessakh, Fatima Zohra. "Étude de nouveaux fluides de travail constitués de solvants à eutectique profond pour les pompes à chaleur." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0262.
A significant amount of waste heat is generated and rejected by industrial processes. This waste heat at low temperature can be upgraded using absorption heat transformers. Absorption heat thermo-transformers use conventional working fluids such as {water + lithium bromide} or {ammonia + water} systems. Nevertheless, the use of these working pairs in the processes has certain drawbacks such as corrosivity, toxicity or even crystallization. Other working fluids consisting of ionic liquid have also been considered. However, these solvents show significant toxicity and high costs. This study aims to evaluate the performance of working fluids consisting of a deep eutectic solvent (DES) and water in absorption heat thermo-transformers. The liquid-vapor equilibria of five {H2O + DES} systems as well as their thermophysical properties such as density, molar heat capacity and excess molar enthalpy were measured. This experimental work made it possible to develop empirical correlations and to adjust the parameters of the NRTL model in order to characterize the working fluids studied at any point of the absorption heat thermo-transformer. Simulations indicate that the working fluids {H2O + DES} have a performance close to {H2O + LiBr} mixture and they could be an alternative to traditional working fluids
Lataoui, Zied Petit Daniel Bertin Yves Jemni Abdelmajid. "Contribution à l'étude des transferts thermiques au sein des caloducs rainurés identification de la position du front d'assèchement /." Poitiers : I-Médias, 2008. http://08.edel.univ-poitiers.fr/theses/index.php?id=2490.
Lataoui, Zied. "Contribution à l'étude des transferts thermiques au sein des caloducs rainurés : identification de la position du front d'assèchement." Poitiers, 2008. http://theses.edel.univ-poitiers.fr/theses/2008/Lataoui-Zied/2008-Lataoui-Zied-These.pdf.
Heat pipes are thermally efficient devices used in many applications (electronics, telecommunication, aerospace,…) for heat management and regulation. In particular, heat pipes are considered as practical solutions for thermal distribution and heat dissipation problems in satellite panel surface. Heat pipe performance test is typically performed using some few wall temperature measurements. However, in such approach, the heat pipe operation phenomena cannot be conveniently investigated. For this aim, an axially grooved heat pipe is experimentally characterized using a test bench, to establish stationary wall temperature distributions for various operating conditions. The obtained temperature profiles show that the evaporator region includes the most important temperature gradients as a consequence to the input heat load increase. A sudden and significant temperature increase is therefore observed since the burnout limit is attained. In the evaporator section, an expected progression of the dry out can be then used to interpret experimental results. Nevertheless, ground test (1g) results cannot efficiently be discussed due to the existence of liquid puddle in the heat pipe bottom section. An inverse analysis is then proposed to localise dry out front positions in every axial groove of the evaporator region, using wall temperature measurements. The obtained results show that the dry out zone expands within the evaporator section as the heat load is increased. The significant temperature increase obtained in the evaporator wall can be therefore explained by the incapacity of the grooves to liquid feed the heated section (capillary limit). When an adverse tilt is introduced, the dry out is also involved in the adiabatic section. The important role of the capillary pumping capacity is also emphasized as a key parameter of the investigated heat pipe operation
Peuvrel, Christophe. "Etude des transferts thermiques lors de la circulation dans un échangeur d'un fluide frigoporteur à changement de phase solide-liquide." Pau, 2003. http://www.theses.fr/2003PAUU3018.
The use of an intermediate secondary refrigerant circuit in indirect cooling process can represent a solution to reduce natural refrigerant volumes and so to contribute to protect environment. In this context, a new generation of secondary fluid has been developed : a phase changing secondary refrigerant, named " Ice slurry ", which is represented by a pumpable mixture of a water solution and fine ice crystals. These thermal fluids offer attractive oportunities for thermal energy transportation and the heat transfer nhancement of heat exchangers notably thanks to latent heat of fusion. The heat transfer and friction characteristics of a 10% (wt/wt) ethanol/water ice slurry has been studied in different double pipe heat exchangers. Measurements were obtained for ice mass fractions ranging from 0% to 25% and velocities between 0,3 and 1,85 m. S-1. For some velocities, the results show that an increase in ice fractions causes a change in the slurry flow structure, influencing the evolution of the pressure drops and the heat transfer coefficients. In the last part of this work, we present an exergetic study of the two-phase mixture, which enables to determine a thermodynamic parameter to choose secondary refrigerant and the couple temperatureconcentration to use for a specific cooling process
Rios-Rojas, Carlos. "Etude des propriétés de transferts thermiques des coulis de glace stabilisée." Lyon, INSA, 2005. http://theses.insa-lyon.fr/publication/2005ISAL0021/these.pdf.
The purpose of this work is the experimental study of the heat transfer properties of a two-phase cooling fluid : stabilized ice-slurry. This ice-slurry is made of millimetric organic gel particles of 90 % porosity filled with water, in suspension in silicon oil. A specific installation was built up, essentially made of two identical smooth plate heat-exchangers ; one cooled by an alcohol flow, the other one heated with electric elements. This device allows to determine the steady-state local heat transfer coefficients during the freezing and the melting processes of the ice-slurry. These coefficients are derived from thermocouple temperature measurements : the temperature of the fluid and the temperature of each side of the heat-exchanger wall which are thus used as fluxmeters. The influence of the ice-slurry flow rate and of its particle concentration is also studied. A strong evolution of the local heat transfer coefficients is observed along one quarter of the heat-exchanger plate. During the melting process, with laminar flow conditions, the average heat transfer coefficient of the cooling fluid is 100 % greater with 20 % particle concentration than without particles. The increase of the heat transfer coefficient rises up to 200 % with 30 % particle concentration. During the melting process, with turbulent flow conditions, the increase of the heat transfer coefficient varies from 200 to 300 % depending on the particle concentration
Liu, Qiusheng. "Couplage entre forces interfaçiales dans un système multicouche de fluides immiscibles, avec ou sans effet des forces thermogravitionnelles." Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX22065.
Belkadi, Abdelkrim. "Modélisation de la matière avec l'équation SAFT pour la prédiction des propriétés thermodynamiques des fluides complexes à travers simulis thermodynamics." Phd thesis, Toulouse, INPT, 2008. http://oatao.univ-toulouse.fr/7781/1/belkadi.pdf.
Houriez, Nicolas. "Etude du transport thremique dans des fluides complexes par calorimètrie photopyroélectrique." Littoral, 2008. http://www.theses.fr/2008DUNK0268.
In this work, a new methodology for the simultaneous determination of thermal parameters (thermal diffusivity, thermal effusivity, thermal conductivity and heat capacity) and pyroelectric coefficient of a pyroelectric material has been developed. This methodology is based on the study of pyroelectric signal generated by the pyroelectric sample when irradiated by a light source intensity modulated. Initially, a theoretical model was developed from the general theory of technique photopyroelectric corresponding to a configuration of the cell as simple as possible. A normalization procedure pyroelectric signal was proposed to eliminate experimental parameters whose value is difficult to estimate. Different procedures for determining the thermal parameters of pyroelectric sample have been proposed : they may be reduced from the development phase or the amplitude of the normalized frequancy modulation. For each of the proposed procedures, a detailed study has assessed the error in determining thermal parameters based on experimental parameters. For measurements based on temperature, two different procedures have been proposed : the first is based on the combination of phase and amplitude of the signal at a given frequency modulation, the latter uses the value of the normalized phase two different frequencies. In addition, it has been shown that the temperature dependence of pyroelectric coefficient could also be measured from the amplitude of the pyroelectric signal. Another application of the method is the measurement of thermal effusivity liquid when the pyroelectric material is well characterized, then playing the role of sensor. It is not necessary to know the thickness of liquid film in thermal contact with the pyroelectric material, which makes measuring simple and applicable to highly viscous fluids. Finally, the first measurements of thermal parameters performed on a ferroelectric liquid crystal were presented. The pyroelectric signal obtained as a funtion of frequency and temperature is similar to that obtained with a pyroelectric material “classic”. The method allows the characterization of ferroelectric liquid crytals also produced in film form. The results obtained for a single crystal, a ceramic, a polymer and a ferroelectric liquid crystal have shown that the method could be applied for the characterization of pyroelectric materials of any kind
Rahli, Ouamar. "Etude des milieux poreux constitués de fibres rigides : empilements, écoulements et transferts de chaleur." Aix-Marseille 1, 1997. http://www.theses.fr/1997AIX11064.
Guérin, Romuald. "Estimation des hétérogénéités de traitement lors de la cuisson de fluides alimentaires polyphasiques en cuves mécaniquement agitées." Nancy 1, 2003. http://www.theses.fr/2003NAN10166.
In this work, a system that allows obtaining dynamic images of temperature fields from a set of 19 electrical property measurements of the agitated fluid via a number of electrodes which are mounted non-intrusively on the vessel boundary has been developped. Using this system, it was shown the existence of thermal gradients within the vessel. In the same time, the developed tool permits to appreciate structural heterogeneity of texturing foods during cooking from a detection algorithm based on the log-likelihood ratio and applied on the first derivative of the delivered electrical signal. Experimental studies were performed with model fluids, simulating the behavior of real food fluids. That was necessary in order to be freed from the seasonal variations of real foods and to be able to discuss the physical phenomena observed during cooking of such fluids
Marmoret, Laurent. "Utilisation d'un matériau poreux dans une paroi thermorégulatrice : modélisation et étude expérimentale des transferts de masse et de chaleur en modes chauffage et rafraichissement." Lyon, INSA, 1998. http://www.theses.fr/1998ISAL0007.
A method was proposed in order to increase the value of clayey fillers which are generally considered as quarry waste. This work described the heat and mass transfers through a clayey-cement concrete lightened with Aluminum powder. Mechanical and thermal characteristics were studied and their variations with water content and temperature were analyzed. The results were inserted into an estimated global model describing thermal and humidity transfers. The variables were temperature and the apparent densities of water vapor and liquid water. The stability of the numerical model was successfully tested. A test wall was built in order to compare the experimental and numerical approaches during heating and cooling. Two types of energy fluxes were studies: firstly, fluxes due to energy radiated by water flowing through a pipe located at the centre of the wall, secondly, fluxes through the external surfaces of the wall and due to variations in the room temperature and humidity. The estimated model was used to study the interest of lightened clayey-cement concrete compared to mortar. It was proved that such a porous clayey material presented considerable advantages compared to other materials often used in surface heating and cooling systems
Pourtier, Emilie. "Les lanthanides dans les fluides géologiques : étude expérimentale des propriétés thermodynamiques standard et des solubilités." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00133813.
De nouvelles PTS (volumes et capacités calorifiques molaires apparentes) des Ln3+ ont été déterminées jusqu'à 300°C et 300 bars à l'aide d'un densimètre à tube vibrant et d'un calorimètre différentiel à écoulement, en utilisant des solutions de triflates de (La3+, Nd3+, Gd3+, Yb3+). L'anion triflate (CF3SO3), stable à haute température, ne complexe pas avec Ln3+. Les PTS de HCF3SO3 et de NaCF3SO3 sont mesurées pour obtenir les PTS de CF3SO3.
D'autre part la solubilité du pôle pur de la monazite (NdPO4) étudiée entre 300°C et 800°C, à 2 kbars, dans H20 et H20+NaCl, par perte de masse et par dilution isotopique, est prograde pour des pH neutres. L'étude de la spéciation de Nd3+ à 650°C et à 300°C, à 2 kbars, montre que seules les espèces hydroxylées sont présentes.
Ces données permettent la révision des paramètres de Ln3+ dans le modèle HKF.
Le, Goff Clément. "Transfert de chaleur dans les solutions nanocolloïdales bidimensionnelles et dans les films de fluides simples ultraminces soumis à un cisaillement." Nantes, 2011. http://www.theses.fr/2009NANT2144.
Bou, Lawz Ksayer Elias. "Étude et conception de systèmes à efficacité énergétique améliorée fonctionnant au CO2 comme fluide frigorigène." Phd thesis, École Nationale Supérieure des Mines de Paris, 2007. http://pastel.archives-ouvertes.fr/pastel-00625025.
Bouhouch, Ahmed. "Modélisation des écoulements monophasiques et des transferts de chaleur en milieux poreux : situations transitoires à masse volumique variable et à haute température." Toulouse, INPT, 1996. http://www.theses.fr/1996INPT045H.
Hilic, Sacha. "Mise au point d'une technique couplée, détecteur à fil vibrant et méthode pVT, pour la mesure simultanée du gonflement d'un polymère lors de l'absorption d'un fluide supercritique et de la solubilité du fluide dans le polymère." Clermont-Ferrand 2, 2000. http://www.theses.fr/2000CLF2A001.
Pan, Jing. "Effet de la température et de l'agitation sur les propriétés rhéologiques des bétons fluides à rhéologie adaptée." Thèse, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/7567.
Abstract : The local climate, the transport of agitated concrete after manufacturing but before being cast strongly influence the properties of the fresh and hard concrete. It’s important to keep the stability and workability of the self-consolidating concrete (SCC) because of its special characteristics. Compare to the normal concrete, the properties of SCC are generally more sensitive to the temperature and the transport. Therefore it’s necessary to understand the effects of the temperature and the agitation on the performance of the SCC in order to predict the consequences of climate change (temperature) and transport (time and speed of agitation), and then to give the better precautions with a good performance-cost report. In this study, the concrete mortar equivalent (CEM) method is used to quickly analyze the influences of the temperature and the agitation on the rheological, calorimetric and mechanical properties of the SCCs. Five temperatures (8, 15, 22, 29 and 36°C) and two agitation speed (6 and 18 tr/min) are varied in CEMs. And then, some compositions (type of adjuvant and supplementary cementing material) are chosen to be valued with the temperature (8-36°C) and the agitation (2 and 6 tr/min) in SCCs for the building without air-entraining admixture (AEA) and semi-flowable SCC for infrastructure with AEA. The initial slump flow of CEM and SCC is fixed, but the demand superplasticizer, the temperature and the agitation were varied. The results show that there are the effects of temperature and agitation on the effectiveness of admixture, the slump flow, the air content, the rheological, calorimetric and mechanical properties of CEM and SCC. A mathematical equation is proposed to predict the performance of SCC at different temperatures for the SP and AEA requirement, the maximum of heat flow and the compressive strength at one day by these same properties of SCC at 22°C and by the temperature. Finally, a good linear correlation is found between CEM and SCC for these properties.
Bénézech, Thierry. "Étude de la distribution des temps de séjour, des performances thermiques et de la consommation de puissance d'échangeurs de chaleur à surface raclée traitant des produits non-newtoniens." Nancy 1, 1988. http://www.theses.fr/1988NAN10432.
Romestant, Cyril. "Etudes théoriques et expérimentales de caloducs et de thermosiphons soumis à de fortes accélérations." Phd thesis, Université de Poitiers, 2000. http://tel.archives-ouvertes.fr/tel-00130174.
Les différentes limites de fonctionnement sont abordées en détails à partir d'une étude bibliographique importante. Des hypothèses nouvelles sont avancées pour le calcul de la limite sonique.
Au travers d'une vaste étude bibliographique, nous abordons les notions de conductances thermiques dans la zone évaporateur et condenseur du caloduc, que ce soit pour les caloducs ayant une structure capillaire ou pour les thermosiphons à tube lisse. Cette observation minutieuse de la physique interne nous a conduit à examiner, à l'évaporateur, les échanges thermiques à travers des films liquides minces en introduisant la notion de pression de disjonction et de résistance d'évaporation.
D'autre part, un montage expérimental complexe et unique au monde à notre connaissance nous a permis de tester trois caloducs cuivre-méthanol sur une plage de température de [0, 100°C] pour des puissances jusqu'à 1400 W et soumis à des champs d'accélération de 1 à 9 g.
Si une partie des résultats expérimentaux obtenus est conforme à nos attentes, de nombreux comportements restent inexpliqués mais permettent d'orienter les recherches futures pour augmenter la prédictibilité des modèles ou des corrélations sur de vastes gammes d'évolution des paramètres (température, puissance, accélération, fluide, matériau, dimensions, structure capillaire, ...)
Sharma, Deewakar. "Modélisation numérique des fluides fortement compressibles proches du point critique." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0003/document.
A fluid, in addition to its liquid and gas phase, is known to exist in another phase, wherein the fluid inherits some properties of both the phases. Such a fluid is called a supercritical fluid and the conditions (pressure and temperature) beyond which the fluid exists in this state is called the critical point. One of the peculiar feature of the fluids near the critical point is that the various thermo-physical properties show a singular behavior, such as diverging compressibility, vanishing thermal diffusivity etc. The flow behavior near the critical point leads to intriguing flow features ascribed to the strong thermo-mechanical coupling whose in-depth investigation can be limited by experimental constraints especially during a continuous transition from supercritical to subcritical regime. The current work focuses on analyzing the flow behavior in near-critical fluids with prime focus on supercritical fluids. This is achieved by developing a mathematical and numerical model which is followed by the validation study and error analysis of the numerical scheme wherein unusual behavior of the Courant number is observed. Subsequently, the flow behavior of supercritical fluid is studied when simultaneously subjected to thermal quench and vibration, mainly Rayleigh-vibrational and parametric instabilities, their physical mechanism and various parameters affecting them. In addition, two captivating phenomena, firstly where the temperature of the fluid region drops below the imposed boundary condition and secondly, the see-saw motion of the thermal boundary layer are observed and physical explanations are provided. In order to investigate the flow dynamics in subcritical regime, phase-field modelling approach is explored for isothermal conditions. The model is examined for elementary test cases illustrating the feasibility to extend the model for a continuous transition from supercritical to subcritical regime
Mao, Visot. "Nouveaux matériaux à conduction mixte protonique-électronique : Développement de membranes sélectives destinées à la séparation de l'hydrogène." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT189/document.
The formulation of high-performance mixed protonic-electronic conductors (MPEC) presents a major advancement for the development of hydrogen-linked application. In particular, this class of materials constitute a promising alternative to the metallic or porous membranes for devices devoted for separation of hydrogen. Thus, objective of this thesis work is to develop, characterize materials presenting sufficient conductivities for the targeted applications, to fabricate the membrane and to evaluate their performances.The first approach consisted of developing single-phase materials by substitution of proton-conducting oxides by a multivalent element, Ba(Ce0.5Zr0.5)0.9-xPrxY0.1O3-δ. In parallel, our works focused on the ceramic-ceramic composites which were consisted of a proton-conducting phase and an electron-conducting phase in reducing conditions, xBaCe0.9Y0.1O3-δ-(1-x)Ce0.9Y0.1O2-δ et xBaZr0.9Y0.1O3-δ-(1-x)CeY0.1O2-δ.The most promising results in terms of conductivity (> 100 mS.cm-1 @ 600°C) was obtained with the composite of composition 20BaZr0.9Y0.1O3-δ-80CeY0.1O2-δ which presented hydrogen permeability in the same order of magnitude as the best values reported in the literature
Liu, Yang. "Développement de méthodes d'identification des propriétés thermo-physiques de matériaux semi-transparents Résolution de problèmes conducto-radiatifs instationnaires en 2d axisymétrique pour l'identification de propriétés thermophysiques de matériaux semi-transparents." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2019. http://www.theses.fr/2019ESMA0019.
This thesis aims to develop the methods for characterizing the thermophysical properties of semi-transparent materials. First of all, an unsteady axisymmetric 2D conductive-radiative direct model aiming at modeling a "flash method" experiment in which excitation is localized in space and time is developed. The radiative heat transfer within the material characterized by the mean absorption coefficient is simplified by using the P1 method. The simplified radiative heat transfer equation, as well as the energy equation, are solved by the finite volume method. Afterwards, an identification model coupling the direct simulation, the experimental data and the particle swarm algorithm (PSO) is developed to simultaneously identify the thermal conductivity and the mean absorption coefficient of the semi-transparent material. In the next part, an identification model based on a multilayer artificial neural network is proposed and tested. The training and test phases of the neural network are performed using a database generated by the direct model. Synthetic data with different noise levels and experimental data are used to respectively demonstrate the robustness and feasibility of this approach to solve practical problems. Finally, in order to reduce the calculation time and increase the identification efficiency, a low-order reduced model of the direct model is built using the modal identification method and tested under different boundary conditions. The coupling of this reduced model with experimental data is not implemented, which are considered as one of the perspectives of this thesis
Pottier, Basile. "Les fluctuations de surface pour mesurer les propriétés de systèmes complexes en l'absence de sollicitation." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00936208.
Ghoubali, Redouane. "Développement d’un prototype préindustriel de thermofrigopompe de petite à moyenne puissance." Thesis, Rennes, INSA, 2013. http://www.theses.fr/2013ISAR0029.
In the current context of hardening of thermal regulations to improve the energy efficiency of buildings, it is necessary to reconsider the heating, cooling and domestic hot water installations. A multifunctional heat pump system for simultaneous heating and cooling (HPS), which simultaneously produces cooling and heating energy, seems to be an interesting solution. The use of a refrigerant with low global warming potential (GWP expressed in equivalent emissions of CO2) in the refrigeration machinery can respond effectively to the problem of reducing greenhouse gas emissions. This work presents a pre-industrial prototype of HPS using propane as refrigerant. Propane (R290) is interesting firstly for its low environmental impact (zero ODP and GWP100 = 3) and for the energy performance. The prototype is the result of the collaboration between the Technical Centre for refrigeration and HVAC, Pôle Cristal and LGCGM laboratory. A new architecture of the refrigerant circuit of the HPS is proposed with a significant reduction in the number of valves. This architecture allows for efficient recovery of the refrigerant charge when switching between modes. The needs for heating, cooling and domestic hot water for three types of buildings in different climates are obtained by simulation using TRNSYS. The nature of the building and climate strongly influence the simultaneous nature of the needs. A ratio of simultaneous needs (RSN) is proposed to identify the most suitable building for the simultaneous production of heating and cooling energy. Climate chamber tests were used to validate the operation of the prototype and characterize its performance. These experimental results were used to calibrate the models of components and refrigerating machines for each operation developed with EES software. A collective residential building and an office building were selected in the comparative study, in order to evaluate the influence of the nature of the requirements on the performance of the HPS. Annual performance simulated by the co-solving method (EES-TRNSYS) of HPS is compared to a reference solution that combines a reversible air / water heat pump for heating, cooling and thermodynamic water heater for domestic hot water. The simulation results of the seasonal performance showed that the office building is interesting in the case of areas requiring a strong need for refreshment throughout the year
Arvengas, Arnaud. "Cavitation acoustique dans l'eau et quelques liquides organiques : densité et limite de rupture." Phd thesis, Université Paris-Diderot - Paris VII, 2011. http://tel.archives-ouvertes.fr/tel-00710980.
Daviau, Noëlie. "Études fines des échanges énergétiques entre les bâtiments et l'atmosphère urbaine." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1005/document.
This thesis work is about the effect of buildings on the urban atmosphere and more precisely the energetic exchanges that take place between these two systems. In order to model more finely the thermal effects of buildings on the atmospheric flows in simulations run under the CFD software Code_Saturne, we proceed to couple this tool with the building model BuildSysPro. This library is run under Dymola and can generate matrices describing the building thermal properties that can be used outside this software. In order to carry out the coupling, we use these matrices in a code that allows the building thermal calculations and the CFD to exchange their results. After a review about the physical phenomena and the existing models, we explain the interactions between the atmosphere and the urban elements, especially buildings. The latter can impact the air flows dynamically, as they act as obstacles, and thermally, through their surface temperatures. At first, we analyse the data obtained from the measurement campaign EM2PAU that we use in order to validate the coupled model. EM2PAU was carried out in Nantes in 2011 and represents a canyon street with two rows of four containers. Its distinctive feature lies in the simultaneous measurements of the air and wall temperatures as well as the wind speeds with anemometers located on a 10 m-high mast for the reference wind and on six locations in the canyon. This aims for studying the thermal influence of buildings on the air flows. Then the numerical simulations of the air flows in EM2PAU is carried out with different methods that allow us to calculate or impose the surface temperature we use, for each of the container walls. The first method consists in imposing their temperatures from the measurements. For each wall, we set the temperature to the surface temperature that was measured during the EM2PAU campaign. The second method involves imposing the outdoor air temperature that was measured at a given time to all the surfaces, reducing every heat exchange to almost zero. The third method at last is the coupled simulation of Code_Saturne and BuildSysPro where BuildSysPro calculates the wall temperature from the Code_Saturne data. . The results of these different ways of modelling the wall temperatures are then compared in order to show the thermal effects of building wall heating on the air flows. We notice that the dynamic effects are dominant and can generate vertical wind speed that can pass several meters per second. On the other hand, differences of surface temperatures higher than 15°C can influence the vertical wind speed for less than 0.5 meters per second. These thermal effects are not easily highlighted with measured data because of the other phenomena that can impact the air flows. However they can be quantified with numerical studies
Chaban, Levgeniia. "Investigation of thermal and mechanical behavior of ultra-thin liquids at GHz frequencies." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1039/document.
The phenomenon of liquid structuring near interfaces is related to the liquid/interface interaction forces at distances of some molecular dimensions. Despite the fact that this universal structuring effect plays a key role in various fields such as heat transport, particle transport through biological membranes, nanofluidics, microbiology and nanorheology, the experimental investigation of liquid structuring remainschallenging.The aim of this PhD thesis is the experimental study of the structuring/ordering of liquids at nanoscale distances from their interfaces with solids. In this context, we have adapted the experimental technique of picosecond laser ultrasonics to investigate high-frequency longitudinal acoustic properties of ultrathin liquids confined between solid surfaces of different types. At first, we will present results of time-domain Brillouin scattering (TDBS) used to determine the temperature distribution profile in the investigated liquid volume which can be extrapolated to nanometer dimensions. Results for the evolution of the extracted Brillouin scattering frequencies and attenuation rates recorded at different laser powers give insight to the intrinsic relationship between thermal and mechanical properties of liquids. Second, we will describe our results for the measurements of mechanical properties of ultrathin liquids with a nanometric resolution. Fourier analysis of the recorded TDBS signals for different liquid thicknesses yield the value of the longitudinal speed of sound and attenuation at GHz frequencies. This novel TDBS experimental scheme is a first step towards the understanding of confined liquids measured by GHz ultrasonic probing
Malakhova-Ziablova, Irina. "Asymptotic and numerical methods for fluid-structure interaction problems and applications to the materials science and engineering." Thesis, Saint-Etienne, 2015. http://www.theses.fr/2015STET4003/document.
The goal of this multi-disciplinary thesis is to study the fluid-structure interaction problem from mathematical and physical viewpoints. Viscous fluid-structure interaction problems describe, for example, interactions between the Earth mantle and the Earth crust, the blood and the vascular wall in a blood vessels, etc. In engineering viscous fluid-structure interaction appears during colloidal solution formation when a laser pierce through the fluid influencing the substrate (laser ablation in a liquid). Selective laser melting (SLM) is used to study the behavior of residual stresses depending on the thermoelastic and mechanical properties of the material and on various forms of reloaded beads. From mathematical point of view the coupled system “viscous fluid flow-thin elastic plate” in 3D when the thickness of the plate, E, tends to zero, while the density and the Young’s modulus of the plate material are of order 1 and E-3, respectively, is considered. The plate lies on the fluid which occupies a thick domain. The multi-scale modeling is performed for the elastic part. The complete asymptotic expansion is constructed when E tends to zero. The existence, the regularity and the uniqueness of the solution for the original problem are studied by means of variational techniques. The method of asymptotic partial domain decomposition is applied for the coupled system. The error of the method is evaluated
Bykalyuk, Anna. "Contribution à l'étude des échanges convectifs à l'interface fluide paroi en présence de matériaux à changement de phase : Application au bâtiment." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0132/document.
Recent experimental studies have shown that the usual values of the convective heat transfer coefficient h are no longer valid in the presence of phase change materials. Three separate models were developed. Initially a model 1 which treats the fluid-wall (constant temperature) interaction in steady laminar flow has been developed and validated. Then, the wall with heat capacity (model 2) subjected to an air temperature ramp were studied. Finally, a third model (3) has been developed which treats the interaction fluid-wall which contains a phase change material. The results show local peaks of heat flow over time. This fact reflects the phase change inside the wall. Moreover, the curves of the convective heat transfer coefficient indicate the dependence of the coefficient h to the wall’s energy storage capacity. Therefore, the presence of the phase change materials within a wall effect and changes the shape of the thermal boundary layer