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Reungoat, David. "Analyse de la température à l'interface d'une garniture mécanique par mesure par thermographie infrarouge". Poitiers, 1994. http://www.theses.fr/1994POIT2355.
Pełny tekst źródłaLegrand, Anne-Claire. "Thermographie multispectrale haute et basse température : application au contrôle non destructif". Dijon, 2002. http://www.theses.fr/2002DIJOS014.
Pełny tekst źródłaHenry, Robert. "Étude du fonctionnement d'un dégivreur électrique : modélisation et mesure en soufflerie givrante de température pariétale par thermographie infrarouge". Clermont-Ferrand 2, 1989. http://www.theses.fr/1989CLF21190.
Pełny tekst źródłaGilblas, Remi. "Mesure de champs de températures vraies par thermo-réflectométrie proche infrarouge". Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0012/document.
Pełny tekst źródłaTrue temperature field measurement is a key parameter for the optimization and the control of industrial processes. Current systems present limitations, especially on heterogeneous surfaces and/or in dynamical conditions involving the surface's variation. These restrictions are due to the ignorance of the surface's emissivity, which is a complex function of many physical quantities (temperature, wavelength, roughness, direction of detection). This thesis presents the complete development of a new method of true temperature field measurement, called Thermoreflectometry, applicable on any kind of opaque material, in the range [300-1000]°C. It allows the on-line measurement of emissivity by mixing a step of classical THERMOGRAPHY with a step of laser REFLECTOMETRY. The approach of this work is, first, the critical analysis of the method and its influence quantities, and then the optimal dimensionment of the components by simulation studies. Thirdly, a prototype is built and its defaults are characterized, following a CAMERA-based point of view, and the possible corrections are implemented. Finally, the experimental performances are estimated on some complex heterogeneous thermal scenes which emphasize the prototype's precision for all the tested samples
Groz, Marie-Marthe. "Reconstruction 3D de sources de chaleur volumiques à partir des champs de température de surface mesurés par thermographie InfraRouge". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0135.
Pełny tekst źródłaNon Destructive Testing (N.D.T.) of materials and structures is a very important industrial issue in the fields of transport, aeronautics and space and in the medical domain. Active infrared thermography is a N.D.T. method that consists in providing an external excitation to cause an elevation of temperature field in the material and then to evaluate the resulting temperature field at the surface. However, thermal exciters used (flash lamps, halogen, lasers) act only on the surface of the sample. Several energy conversion systems can on the other hand lead to the generation of volumetric sources: the phenomena of thermo-acoustic, thermo-induction, thermomechanic or thermochemistry can be cited. For example, ultrasonic waves can generate volumetric heat sources if the material is viscoelastic or if there is a defect. The reconstruction of these sources is the first step for the quantification of parameters responsible of the heating. Characterizing a heat source means reconstructing its geometry and the power it generates. For example, a defect in a structure and / or the viscoelasticity of a material can be detected and quantified by this technique if it acts directly on temperature field. However, identification of volumetric heat sources from surface temperature fields is a mathematical ill-posed problem. The diffusive nature of the temperature is the main cause. In this work, the 3D reconstruction of the volumetric heat sources from the resulting surface temperature field, measured by InfraRed, is studied. First, an analysis of the physical problem enables to specify the limits of the reconstruction. In particular, a criterion on achievable spatial resolution is defined and a reconstruction limitation for in-depth sources is highlighted. Then, a probabilistic approach for the reconstruction is proposed and compared to existing inverse methods. The computation time and noise sensitivity are studied for each of these methods. Numerical and experimental applications will thus be presented to illustrate the results
Daviot, Ronan. "Etude des champs de flux thermique sur les composants faisant face au plasma dans un tokamak à partir de mesures de température par thermographie infrarouge". Phd thesis, Ecole Centrale Paris, 2010. http://tel.archives-ouvertes.fr/tel-00534809.
Pełny tekst źródłaGilblas, Rémi. "Mesure de champs de températures vraies par thermoréflectométrie proche infrarouge". Phd thesis, INSA de Toulouse, 2012. http://tel.archives-ouvertes.fr/tel-00797425.
Pełny tekst źródłaLacourarie, Fiona. "Caractérisation thermique et lumineuse de diodes électroluminescentes en charge par méthodes locales non intrusives : influence du luminophore". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2015. http://www.theses.fr/2015EMAC0003/document.
Pełny tekst źródłaThe high brightness LED market is constantly growing last twenty years. The lighting market is changing as needs have changed: we would like, for example, reduce power consumption, or have more flexible lighting (color, lighting cycle, dimensions ...). High brightness LEDs help provide solutions where others are lighting defects. A comparative study is conducted between the LEDs and other lighting sources.The operation of a high brightness LED emitting white light is explained with the description of each element: chip, substrate, the PAD and optics. Then the different methods of obtaining white light with LEDs are compared: several chips, a chip with one or more phosphors, or PRS-LED method. The phosphor has a significant optical role and an important thermal role. After being excited by the light emitted from the chip, it re-emits light in a greater wavelength. The effectiveness of this process depends on many parameters, such as the implementation of the phosphor, or the type of phosphor used. The study and characterization of optical and thermal properties are made for commercial LEDs, composed of a single chip emitting blue light with and without yellow phosphor. To master the maximum factors, we conducted a study and design of the printed circuit board (PCB) on which will be implanted our LEDs. In order to evaluate the materials constituting the LEDs, analyzes made at scanning electron microscope, and by microprobe were conducted. This work has revealed in particular the position of the p-n junction in the chip, and the composition of the phosphor layer of two different types. Moreover, to improve our understanding, a comparative study will be conducted on three yellow phosphors. Then the two types of LEDs, bare chip and chip with phosphor, were tested in order to obtain the luminous flux and efficiency of LEDs. The optical characterization has led us to create a bench for spectral radiance over a small portion of the chip. Furthermore, we are interested in the junction temperature of the bare chip, which we measure by various methods, including infrared thermography. For this, the emissivity was estimated for the bare chip and the chip with phosphor. Then we also compare these different methods to calculate the thermal resistance Rth j-PAD between the junction and the PAD. The mesh of conductive wires, implanted on the surface of the chip, is electrically modeled. The study, which is composed of three progressive levels of modeling, provides an understanding of distribution of the electric current through the junction, and thus to understand the distribution of the light flow and temperature at the surface of the chip. Afterwards, an optical-thermal model describes the phenomena present at the junction of a bare chip: converting electrical power into blue light and heat, and heat transfer. We complete this first model for a model of a chip with the phosphor. This model takes into account the photo-conversion of the phosphor with the calculation of the luminous flux at the output of the phosphor and the calculation of the heat due to the photo-conversion. The resolution of this model allows us to obtain the junction temperature of a chip with phosphor. The model of energy conservation is also verified. The optical-thermal model is applied to a surface temperature mapping in order to obtain a mapping of the junction temperature. These maps are combined with pictures of infrared thermography and radiance
Mergui, Mohamed. "Mesure de contraintes dynamiques par thermographie infrarouge". Lyon, INSA, 1995. http://www.theses.fr/1995ISAL0093.
Pełny tekst źródłaIn order to generate the validity of the measurements by infrared camera, it is necessary to know some specific parameters, in particular: -spatial resolution, -thermal resolution, -uniformity of response in the measurement field. This_ thesis approaches the problems of the use of infrared thermography, in order to precise its potentialities in dynamic stress measurement. A new remote stress measurement method has been developed this method , based on thermoelasticity phenomena is usually simpler than the direct method using strain gauges; this latter technique , however, has allowed us to validate our results. New signal and image processing techniques bead to a mapping of stresses on any structure subject to a periodic strain. Infrared thermography is very suitable in the case of stress concentration. The thermal resolution attained after thermosignal processing is of the order of 10-3°c , even when the camera background noise is of the order 10-1 °c
Loarer, Thierry. "Mesure de température de surface par effet photothermique modulé ou impulsionnel". Châtenay-Malabry, Ecole centrale de Paris, 1989. http://www.theses.fr/1989ECAP0114.
Pełny tekst źródłaDjupkep, Dizeu Frank Billy. "Quantification et visualisation des conditions ambiantes intérieures par thermographie infrarouge". Doctoral thesis, Université Laval, 2015. http://hdl.handle.net/20.500.11794/26096.
Pełny tekst źródłaThe level of thermal comfort has become an important criterion to consider during the design of contemporary buildings. In some parts of the world, natural ventilation is not adequate to maintain a comfortable indoor environment. Air conditioning systems are used in order to create a comfortable artificial indoor microclimate. The indoor microclimate is a combination of air temperature, air speed, humidity and mean radiant temperature. In this thesis, we develop a measuring system that uses infrared thermography to measure and visualize the parameters of the indoor microclimate. We begin our investigations by designing a sensor and we proceed to the theoretical validation of its thermal model. This sensor is the auxiliary element which allows the quantification and the visualization of the parameters of the indoor microclimate with an infrared camera. The quantification of these parameters is possible after that an inverse heat transfer problem has been solved. The visualization of these parameters is possible after that the 3D coordinates of a set of sensors placed in the field of view of the camera have been determined. Image processing tools are presented and allow the accurate measurement of sensors temperature and the 3D location of the sensors in real space. Finally, an experimental validation is realized. The results show that the system developed is accurate, reliable, and robust. An infrared camera and a set of sensors wisely arranged in space can be used to quantify and map the indoor microclimate.
Dragan, Razvan Gabriel. "Etudes sur le diagnostic des systèmes par thermographie infrarouge". Thesis, Artois, 2014. http://www.theses.fr/2014ARTO0207/document.
Pełny tekst źródłaThe thesis “Research concerning the systems analyze by infrared thermography” proposestheoretical and experimental researches în the very complex domain of non destructiveinspection methods, especially the infrared thermography – CO2 laser excitation, halogen lamps,electric heat sources, microwaves and electromagnetic induction. The thermographic analyzewas applied on materials used în constructions and biomedical engineering, the goal being theinternal and external defect detection, micro cracks, the detection of the embed metallic materialsand also the analysis of their thermal influence in the heat transfer process. The thesis isstructured in six chapters and, among them: three are concerned on introduction, thesisobjectives, conclusions, original contribution and thesis valorization (published papers andresearch grants)/future research directions. The next three develop, consistently, the thesissubject, beginning with critical analyze of the specialized literature that is followed bytheoretical study, and the experimental study of systems by infrared thermography. The PhDthesis contains 181 figures and 12 tables în which are illustrated and highlighted results andinformation with a high scientific degree. During the research program, the author elaborated andpublished 10 papers in the proceedings of different scientific events in Romania and abroad, insix of them being the first author
Dumoulin, Jean. "Méthodes de détermination, par thermographie infrarouge, des coefficients d'échange de chaleur moyens et instationnaires en aérodynamique perturbée". Toulouse, INSA, 1994. http://www.theses.fr/1994ISAT0021.
Pełny tekst źródłaBerté, Emmanuel. "Mesure de champs thermiques de surface par thermographie bichromatique en situation de frottement haute énergie". Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0033/document.
Pełny tekst źródłaIn highly dissipative contacts, the energy dissipated by friction leads to severe thermal loads which could have bad consequences on performances, on friction parts durability, on the environment or on human health. Therefore, knowledge of sliding surfaces thermal fields is a first-rate issue. Due to the lack of knowledge about the emissivity of those surfaces, which change both spatially and temporally during friction, measuring thermal fields is difficult. The work done concerned the development of thermal fields measurement by bispectral thermography, which allows to get simultaneously surface emissivity and temperature. The difficulties reside in the spatial and temporal images registration of two infrared cameras, in the camera flows calibration and in the spectral emissivity variation. The technique developed was applied to the in situ fields measurement of temperature and emissivity of a brake disc during braking. It was then used for analysis of thermal locations induced by friction and their interactions with the tribological circus, leveraging the knowledge of the spatial and temporal evolution of the emissivity
Grosjean, Alex. "Impact of geometry and shaping of the plasma facing components on hot spot generation in tokamak devices". Electronic Thesis or Diss., Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0556.
Pełny tekst źródłaThis PhD falls within ITER project support, aiming to study the thermal behavior of ITER-like PFC prototypes in two superconducting tokamaks: EAST (Hefei) and WEST (Cadarache). These prototypes correspond to castellated tungsten monoblocks placed along a cooling tube with small gaps (0.5 mm) between them, called plasma-facing units, to extract the heat from the components. The introduction of gaps between monoblocks (toroidal) and plasma-facing units (poloidal), to relieve the thermomechanical stresses in the divertor, implies that poloidal leading edges may be exposed to near-normal incidence angle. A local overheating is expected in a thin lateral band at the top of each monoblocks, which can be enhanced when the neighboring components are misaligned. In this work, we propose to study the impact of two geometries (sharp and chamfered LEs) of these components, as well as their misalignments on local hot spot generation, by means of embedded diagnostics (TC/FBG), and a submillimeter infrared system (~0.1 mm/pixel), whose emissivity varies with wavelength, and the temperature, but above all, the surface state of the component, which evolves under plasma exposure, during the experimental campaigns. The divertor Langmuir probes measure the plasma temperature, and thus estimate the ion Larmor radius that may play a role in the local heat flux distribution around poloidal and toroidal edges. The results presented in this thesis, confirming the modelling predictions by experimental measurements, support the final decision by ITER to include 0.5 mm toroidal beveling of monoblocks on the vertical divertor targets to protect poloidal leading edges from excessive heat flux
Ravel, Olivier. "Système optronique infrarouge : application à la mesure de la température de gouttes dans un écoulement diphasique, en combustion et en impact pariétal". École nationale supérieure de l'aéronautique et de l'espace (Toulouse ; 1972-2007), 1999. http://www.theses.fr/1999ESAE0007.
Pełny tekst źródłaEl, Abbadi Abdelilah. "Développement de méthodes de mesure des transferts convectifs par thermographie infrarouge : application aux ailettes d'échangeurs à hautes performances". Valenciennes, 2006. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/1e108508-defe-4dbb-bc55-cf5ec4fdea4f.
Pełny tekst źródłaThe study presented in this memory concern the measurement and the improvement of the convective heat transfer in finned tubes heat exchangers. For the measurement of convective heat transfer coefficient, two techniques are developed: A transient method that calculate local heat transfer coefficient on the surface of slightly heat conducting fins at constant temperature. And an inverse method with a second-order regularization to calculate this coefficient on fins by taking account of side conduction in these last one. The two methods require the use of temperature fields that we measure using an infrared thermography system. These techniques were then applied to the characterization of the fins of heat exchanger. They also allowed the study of high efficiency thermal fins. The increase of heat transfer on the surface of the latter ones is obtained by the addition of vortex generators
Polet, Frédéric. "Études théorique et expérimentale de la radiométrie par absorption différentielle distribuée appliquée au contrôle de température sans contact". Lille 1, 1999. http://www.theses.fr/1999LIL10073.
Pełny tekst źródłaNoureddine, Saïd. "Influence de la température sur les paramètres électriques caractéristiques des photopiles au silicium polycristallin : modélisations et analyse par thermographie infrarouge". Aix-Marseille 3, 1986. http://www.theses.fr/1986AIX30056.
Pełny tekst źródłaGavérina, Ludovic. "Caractérisation thermique de milieux hétérogènes par excitation laser mobile et thermographie infrarouge". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0012/document.
Pełny tekst źródłaNowadays, composite materials are widely used in the aeronautic and aerospace industries because of their high mechanical resistance. However, they have a large heterogeneity due to the fiber and matrix they are made of. In this way, for many years, the TIC team «Thermal Imaging Fields and Characterization » from TREFLE department of I2M laboratory develops methods to measure thermal in-plane properties of heterogeneous materials such as inverses (integral transforms, double singular value decomposition…) or experimental (Flash, laser diode…) methods. The recent progress made in optical control, lasers and infrared (IR) cameras enables the development of a new scanning system (based on galvanometer-mirror) which allows the easy control of a laser hot spot spatial and temporal displacements over a plane surface. The low cost of laser diodes and optical control (galvanometric mirror) systems allows to develop a laser scanning system fixed on a test bench. We can revisit the different types of thermal excitation and realize infinite spatio-temporal combinations of thermal excitations by laser method. This is one of this thesis aims. New inverse methods based on the thermal response to an instantaneous point source heating, and temperature fields separability, have been proposed. These methods allow to estimate the thermal diffusivity tensor along the main axes of anisotropy, but also out of those axes, where it is possible to estimate the anisotropy axes orientation when the heat transfer takes place out of the image axes. These methods have produced interesting results in view of their simplicity. Moreover, they made it possible to obtain in-plane thermal diffusivities maps because, compared to the other methods, they allow to obtain, locally, thermal diffusivity tensor estimations by getting a surface heat flux map using the laser optical scanner
Alshunaifi, Ibrahim. "Caractérisation de la concentration et de la température d'un nuage de gaz par thermographie infrarouge : application à l'analyse des effluents gazeux". Thesis, Paris 10, 2011. http://www.theses.fr/2011PA100025/document.
Pełny tekst źródłaThe thesis focuses on the cratering of the temperature and the concentration of a gas cloud. The Infrared thermography is the means used at first to detect passive and second step in quantifying the target gas. After analyzing the parameters involved in the equation of radiatif transfer of gas, the study presents the simulation result from several sources (engines, gas leak ...). Different ways of improvement of imaging data by a camera are available : optical filtering in one or two wavelengths, temporal filtering by frequency analysis. hyperspectral equipment was also developed from the combination of a Fourier transform spectrometer with the "detector" a matrix camera sensitive in the infrared. All solutions can save a factor of 10 to 50 on the detection of sources. A quantitative example is finally proposed : determining the volume of CO2 exhaled by an athlete during an effort. This volume increases during exercise. This work therefore leads to non-contact measurement applications in biometrics
Croteau, Martin. "Étude sur les variations spatio-temporelles des températures internes et des émissions thermiques de troncs d'ormes d'Amérique (Ulmus americana) et d'épinettes noires (Picea mariana) par thermographie infrarouge et mesures par thermocouples". Mémoire, Université de Sherbrooke, 2005. http://savoirs.usherbrooke.ca/handle/11143/2445.
Pełny tekst źródłaVermeulen, Jean-Philippe. "Etude de l'influence d'un obstacle sur le transfert thermique convectif en convection naturelle : étude expérimentale par thermographie infrarouge". Valenciennes, 1997. https://ged.uphf.fr/nuxeo/site/esupversions/5806853c-d1d1-4548-be19-6b5f1240785e.
Pełny tekst źródłaLevezac, François. "Mesure de température de surface par cristaux liquides thermochromiques : application à la détermination de flux convectif". Toulouse, ENSAE, 1996. http://www.theses.fr/1996ESAE0016.
Pełny tekst źródłaChauchard, Fabien. "Amélioration de la robustesse des mesures en spectrométrie proche-infrarouge sur produits biologiques". Montpellier 2, 2005. http://www.theses.fr/2005MON20209.
Pełny tekst źródłaCoret, Laurent. "Impact de l'hétérogénéité de surface sur le signal en entrée d'un capteur infrarouge thermique : prise en compte de l'aspect directionnel". École nationale supérieure de l'aéronautique et de l'espace (Toulouse ; 1972-2007), 2002. http://www.theses.fr/2002ESAE0012.
Pełny tekst źródłaCharbal, Ali. "Mesure de champs thermomécaniques pour l'étude de la fatigue par chocs thermiques". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLN007/document.
Pełny tekst źródłaThermal fatigue occurs in nuclear power plant pipes. The temperature variations are due to the turbulent mixing of fluids that have different temperatures. Many experimental setups have been designed but the measured temperatures have only been punctual and out of the zone of interest (e.g., via thermocouples). The equivalent strain variation in the crack initiation region is calculated with numerical thermomechanical simulations. In many cases, the comparisons between numerical and experimental results have shown that the crack initiation predictions in thermal fatigue are non-conservative. A new testing setup is proposed where thermal shocks are applied with a pulsed laser beam while the thermal and kinematic fields on the specimen surface are measured with infrared (IR) and visible cameras, respectively. Experimental testings are performed and different measurement techniques for temperature and kinematic fields are used. IR camera and pyrometers allow to measure the temperature variations in the zone impacted by the laser beam. To estimate the absolute temperature, the surface emissivities at the respective wavelengths are determined by different methods. The absolute temperature field is then used to apply the actual thermal loading in a decoupled FE model after an identification process of the parameters of the laser beam. Once the thermal loading is generated based upon the experimental data, the stress and strain fields can be computed in the region of interest with an elastoplastic law.The experimental strain variations calculated from the DIC measurements are compared with the predictions obtained with the FE simulation
Rodiet, Christophe. "Mesure de Température par Méthodes Multi-Spectrales et Caractérisation Thermique de Matériaux Anisotropes par Transformations Intégrales : « Aspects Théoriques et Expérimentaux »". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0283/document.
Pełny tekst źródłaThis thesis consists of two relatively independent parts, the first part focuses on methods of temperature measurement using Multi-Spectral (passive optical pyrometry) methods, and the second on the Thermal Characterization by integral transforms at high temperature of orthotropic materials. In each of these two parts, methods / models developed were treated from a theoretical point of view, numerical and experimental. In the multi-spectral part, a method of temperature measurement to take into account a spectral variation of the overall measurement chain (including the emissivity) was introduced. Moreover, a method of determining the optimal wavelengths in the sense of minimizing the standard deviation of temperature, has been developed. Finally, it has also been shown that the optimal wavelengths for mono-spectral and bi-spectral measurements could be determined with similar laws to Wien's displacement law. In the Thermal Characterization part, different methods and models have been developed. The proposed methods perform the estimation of longitudinal and transverse diffusivities on all harmonics simultaneously. Furthermore, they allow overcoming the thermal coupling due to the presence of a sample holder, and / or making pseudo-local measurements of diffusivities. Finally, the concepts of correlation between parameters and duration of harmonics exploitability were also discussed.This thesis consists of two relatively independent parts, the first part focuses on methods of temperature measurement using Multi-Spectral (passive optical pyrometry) methods, and the second on the Thermal Characterization by integral transforms at high temperature of orthotropic materials. In each of these two parts, methods / models developed were treated from a theoretical point of view, numerical and experimental. In the multi-spectral part, a method of temperature measurement to take into account a spectral variation of the overall measurement chain (including the emissivity) was introduced. Moreover, a method of determining the optimal wavelengths in the sense of minimizing the standard deviation of temperature, has been developed. Finally, it has also been shown that the optimal wavelengths for mono-spectral and bi-spectral measurements could be determined with similar laws to Wien's displacement law. In the Thermal Characterization part, different methods and models have been developed. The proposed methods perform the estimation of longitudinal and transverse diffusivities on all harmonics simultaneously. Furthermore, they allow overcoming the thermal coupling due to the presence of a sample holder, and / or making pseudo-local measurements of diffusivities. Finally, the concepts of correlation between parameters and duration of harmonics exploitability were also discussed
Samaca, Martinez José Ricardo. "Analyse thermomécanique du comportement cyclique des élastomères par mesure de champs". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-01023976.
Pełny tekst źródłaOuattara, Aboubacar. "Caractérisation du refroidissement par jet liquide impactant une plaque métallique à haute température : Iinfluence de la composition du fluide sur le flux extrait". Thesis, Nancy 1, 2009. http://www.theses.fr/2009NAN10048/document.
Pełny tekst źródłaIn this work, we are interested in the influence of the fluid’s composition on the cooling flux. In fact water used for cooling is recycled and can be potentially polluted by residues oil from the lubrication of rolling cylinder. We have designed an original experimental device which consists of heating a Nickel disk on its upper face at temperatures of 600°C through electromagnetic induction and then cooling it by jet impingement. The reverse face is available by infrared thermography measurements. These conditions allowed us to estimate the heat flux on the upper face (the cooling area) by infrared thermography measurements with a specific inverse heat conduction model. The results showed that the presence of oil, if it degrades the maximum cooling flux in some areas, led to a better overall cooling than that obtained with pure water
Dhokkar, Sonia. "Etude des phénomènes thermiques dans un MOSFET en commutation : mesure de la température à haute résolution spatiale et temporelle par radiométrie proche infrarouge et confrontation à un modèle thermique". Poitiers, 2008. http://www.theses.fr/2008POIT2305.
Pełny tekst źródłaChettaf, Aïssa. "Contribution à l'étude du séchage par rayonnement infrarouge : Application au séchage en couche mince d'une enduction". Valenciennes, 1994. https://ged.uphf.fr/nuxeo/site/esupversions/9a259158-201e-4807-bac7-56fdaf6a482b.
Pełny tekst źródłaMenanteau, Sébastien. "Fluctuations de température en aval d'une jonction orthogonale d'écoulements turbulents de températures différentes". Thesis, Valenciennes, 2012. http://www.theses.fr/2012VALE0016.
Pełny tekst źródłaThis research work originates from thermal stress issues in hydraulic pipes. It specifically focuses on determination of thermal load created by mixing flows in orthogonal pipe junctions. Such mixing zones are commonly used to cool or heat the main flow. For high Reynolds number values and high difference of temperature of the two flows, thermal load created by strong temperature fluctuations at the wall can initiate and propagate cracks through the pipe. Standards in pipe design pointed out the need in knowing these thermal loads applied at the downstream junction wall. Thus, this study aims to characterize three-dimensional and unsteady dynamical and thermal phenomena in a simplified industrial configuration. First, an experimental investigation based on particle image velocimetry and infrared thermography has been carried out on a cylindrical jet pipe flowing through a main rectangular channel flow. Different parameters have been studied such as Reynolds number influence, velocity ratio between secondary and main flow and temperature difference. One of the experimental configurations has also been investigated using numerical simulations. LargeEddy Simulations with conjugate heat transfer model has been developed and compared to the experimental database. Dynamics and Thermal mechanisms have been analysed near the wall and within the wall with obtained statistical flow fields, velocity-temperature moments and numerical probes extracted from fluid and solid parts
El, Bakali Abdelmagid. "Contribution à l’étude des échanges thermiques aux interfaces pour les procédés de formage à chaud : développement de moyens de mesure de l’émissivité et de la résistance thermique de contact (RTC) à haute température A fast and versatile method for spectral emissivity measurement at high temperatures". Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2020. http://www.theses.fr/2020EMAC0004.
Pełny tekst źródłaThe present work deals with the high temperature heat transfers involved in sheet/die contact within hot forming processes. The investigated heat ranges lie between 600°C and 1000°C while the study materials are namely TA6V and Inconel 625 (for the sheet) and AISI 310 stainless steel and refractory concrete (for the die). Under such industrial configuration, the heat transfers can be split in two steps: i) a gap closing phase during which the radiative property of the contact pair prevail and ii) a solid contact phase during which the conductive properties are involved and more precisely the thermal contact resistance (TCR). This twostep approach allows a separate investigation of both phenomena which are herein studied by the mean of two dedicated experimental means: a) The gap closing phase is studied through an emissivity measurement setup dedicated to high temperature. The chosen setup is inspired from elliptical oven setups. Its features include a heating rate over 11°C/s and a maximal in-service temperature of 1250°C. The related measurement instruments selection and design are also part of the presented work. The metrological aspects along with the uncertainty quantification are performed through the use of a reference material: pure platinum. This latter has proven worthy by its ability to sustain very high temperature while remaining free from oxidation. In addition, platinum’s optical properties are well documented throughout the scientific literature which provides solid comparisons with other published results. Finally, the construction of an emissivity database is presented for the two sheet materials of the study: TA6V and INCONEL 625. b) The solid contact phase is studied through a second tailor made experimental setup dedicated to TCR measurements. The proposed features include the ability to study metal contact pair (AISI 310 vs. TA6V/INCONEL 625) or ceramic vs. metal contact (Concrete vs. TA6V/INCONEL 625) for temperature as high as 800°C. The whole setup can be inserted within a classical tensile device in order to load the contact interfaces at stress levels similar to those involved in metal forming processes (here up to 4MPa). In practice, a circular sample cut from the studied sheet metals is clasped in between two cylindrical bars made of AISI 310 or concrete. The upper bar is then heated up by the mean of a resistive oven in order to generate a directional heat flux throughout the material interfaces. A suited measurement instrumentation then allows the assessment of the TRC for each contact pair for temperature ranging from 450°C to 800°C and pressure ranging from 0.1MPa to 4MPa. The results obtained from these two setups have built up a material database that was then use to simulate industrial hot forming operations. The process parameters retrieved from these simulation were used as input in an actual forming process and has led to the successful manufacturing of four parts all of which satisfying the quality requirements in term of geometry and microstructure
Landfried, Romaric. "Contribution à l'étude de la transition décharge luminescente / arc électrique dans l'air et dans l'argon au voisinage de la pression atmosphérique". Phd thesis, Supélec, 2011. http://tel.archives-ouvertes.fr/tel-00789385.
Pełny tekst źródłaSouhar, Youssef. "Caractérisation thermique de matériaux anisotropes à hautes températures". Thesis, Vandoeuvre-les-Nancy, INPL, 2011. http://www.theses.fr/2011INPL029N/document.
Pełny tekst źródłaThe study concerns the thermal characterization at high temperatures of anisotropic materials whose thermal diffusivity varies according to the direction considered. This measurement of diffusivity is allowed by the observation of the transient variations of temperature of a material subjected to a heat pulse source. The excitation is performed by a Laser and the temperature measurement is carried out by infrared thermography on the opposite face of the thermal excitation. The temperature field thus obtained makes it possible to determine the three diffusivities of the material according to its directions of anisotropy. Indeed, thanks to integral transforms of the temperature field, it is possible to obtain a theoretical model describing the temperature variations within the material. The estimates of diffusivities are then obtained by the minimization of the sum of squared residuals between the theoretical models and their experimental equivalents. These are problems of nonlinear optimization and the estimations are carried out in the spatial frequency domain and in time thanks to a numerical inversion of Laplace. Based on optical devices this method is non-intrusive and thanks to the use of analytical models the estimations are fast and accurate even at high temperatures. The method and the new experimental facility make it possible to estimate the three thermal diffusivities in a single experiment and this for excitations of any shape in space and not necessarily Dirac’s delta function in time
Albalat, Nicolas. "Utilisation des données hyperspectrales du capteur IASI pour la restitution des paramètres thermo-optiques des surfaces terrestres". Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00747800.
Pełny tekst źródłaLe, Saux Vincent. "Fatigue et vieillissement des élastomères en environnements marin et thermique : de la caractérisation accélérée au calcul de structure". Phd thesis, Université de Bretagne occidentale - Brest, 2010. http://tel.archives-ouvertes.fr/tel-00542506.
Pełny tekst źródłaAyvazyan, Vigen. "Etude de champs de température séparables avec une double décomposition en valeurs singulières : quelques applications à la caractérisation des propriétés thermophysiques des matérieux et au contrôle non destructif". Thesis, Bordeaux 1, 2012. http://www.theses.fr/2012BOR14671/document.
Pełny tekst źródłaInfrared thermography is a widely used method for characterization of thermophysical properties of materials. The advent of the laser diodes, which are handy, inexpensive, with a broad spectrum of characteristics, extend metrological possibilities of infrared cameras and provide a combination of new powerful tools for thermal characterization and non destructive evaluation. However, this new dynamic has also brought numerous difficulties that must be overcome, such as high volume noisy data processing and low sensitivity to estimated parameters of such data. This requires revisiting the existing methods of signal processing, adopting new sophisticated mathematical tools for data compression and processing of relevant information.New strategies consist in using orthogonal transforms of the signal as a prior data compression tools, which allow noise reduction and control over it. Correlation analysis, based on the local cerrelation study between partial derivatives of the experimental signal, completes these new strategies. A theoretical analogy in Fourier space has been performed in order to better understand the «physical» meaning of modal approaches.The response to the instantaneous point source of heat, has been revisited both numerically and experimentally. By using separable temperature fields, a new inversion technique based on a double singular value decomposition of experimental signal has been introduced. In comparison with previous methods, it takes into account two or three-dimensional heat diffusion and therefore offers a better exploitation of the spatial content of infrared images. Numerical and experimental examples have allowed us to validate in the first approach our new estimation method of longitudinal thermal diffusivities. Non destructive testing applications based on the new technique have also been introduced.An old issue, which consists in determining the initial temperature field from noisy data, has been approached in a new light. The necessity to know the thermal diffusivities of an orthotropic medium and the need to take into account often three-dimensional heat transfer, are complicated issues. The implementation of the double singular value decomposition allowed us to achieve interesting results according to its ease of use. Indeed, modal approaches are statistical methods based on high volume data processing, supposedly robust as to the measurement noise
Pottier, Thomas. "Identification paramétrique par recalage de modèles éléments finis couplée à des mesures de champs cinématiques et thermiques". Phd thesis, 2010. http://tel.archives-ouvertes.fr/tel-00566788.
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