Дисертації з теми "Écoulement chargé en particules"
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El, Kawafi Abdulghadir. "Colmatage d'un milieu poreux saturé soumis à un écoulement chargé de particules." Le Havre, 2010. http://www.theses.fr/2010LEHA0017.
Processes of the mobilisation, the transport and the deposition of solid particles in porous media are an important research topic in different engineering fields and industrials applications. Clogging is a direct consequence of particles transport and deposition in the porous medium resulting on a dramatic reduction in permeability. This thesis aimed to investigate the influence of certain physical parameters such as i) the structure of porous medium, ii) the suspended particles and iii) the hydraulic conditions on the clogging mechanisms that generate the damage of the porous medium. Porous medium damage is identified by the decline of its porosity and its permeability. A parametric experimental study is conducted on laboratory columns. The particles transfer, including the initiation, the development and the localization of clogging is followed by the measurement of i) the hydraulic characteristics of the porous medium, ii) the size distribution of the recovered particles in the effluent, iii) the mass of the deposited particles and its size distribution. Many interesting results are obtained, on the role of each parameter studied, on the space-time evolution of the clogging
Anand, Karan. "Simulation numérique des interactions particule-particule et particule-paroi dans les écoulements turbulents chargés en particules non-sphériques." Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEP014.
There is no denying the fact that particle-laden flows are a frequent occurrence both naturally as well as at the industrial stage. Understanding the behaviour of these flows is complicated because, in addition to the stochastic nature of the turbulent carrier phase, we have to deal with the random behaviour of the dispersed phase and how they affect each other. It is imperative to have detailed knowledge regarding the nature of the dispersed phase (particle-size distribution, shape and how it interacts with one another (collisions, electrostatic forces). A majority of the existing literature on particle-laden flows deals with idealized spherical particles. Whereas, many processes including both natural (ice crystals, pollen grains, phytoplanktons) and industrial (textile or pulp fibres, combustion soot) have particles that are anisotropic in shape. Studying the motion and dynamics of an anisotropic particle in a turbulent is a challenging task. One has to take into account the orientation and rotational motion of the particles which are strongly coupled with the translational motion of the particle. Little is known regarding the effect of collisions if particles are assumed to have a generally ellipsoidal shape. Even frictionless collisions lead to transfer between translational and rotational kinetic energies. This inherent coupling of translation and rotational motion can noticeably change the configuration of the flow. Furthermore, the collision rates and timescales for inertial non-spherical particles have not been studied in this framework. Hence, the purpose of this study is to analyze collisions in non-homogeneous statistically steady flows loaded with ellipsoidal particles to understand, identify the dominant effect and support the development of statistical Lagrangian (Monte-Carlo) or Eulerian approaches. The effect of collisions has been investigated and modelled first for gas-solid channel flow with a binary mixture of spherical particles. Then collisions were examined for ellipsoidal particles in a dry granular flow. Finally, the effect of particle shape on collisions is studied in a channel flow. The fluid drag and lift forces as well as torques applied on the ellipsoidal particles were considered in this case
Petitjean, Alain. "Simulation lagrangienne d'écoulements gaz-solide en conduite avec prise en compte des interactions entre particules." Nancy 1, 1994. http://www.theses.fr/1994NAN10061.
Dugois, Kévin. "Simulation à l’échelle microscopique et analyse macroscopique de l’imprégnation d’un matériau composite par un fluide chargé en particules." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0011/document.
In order to improve thermo-mechanical behavior of tubine blades in SAFRAN engines plane, a new composite material is necessary. The manufacturing process to obtain this composite is intricate and requires a two steps fluid densification process. This thesis focuses on numerical simulation of the first one called Slurry Cats/APS. In this step, suspended particles are introducted and captured in the reinforcement. For that purpose,we carry out a model at fiber scale, using Navier-Stokes equations in incompressible and monophasic formulation, Phillips equations [Phillips et al., 1992] and a rheological law [Krieger, 1972]. After validation step consisting in a comparison of computational results with experiments [Hampton et al., 1997] and theorical law [Belfort et al., 1994], this model has been used to simulate flow around geometries similar to those encountered in our composite material
Tekam, Sydney-Miles. "Modélisation et simulation numérique d'écoulements gazeux chargés de particules d'huile dans un circuit de décantation de moteur." Paris, ENSAM, 2006. http://www.theses.fr/2006ENAM0016.
vermorel, olivier. "Etude numérique et modélisation de la modulation de la turbulence dans un écoulement de nappe chargée en particules." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2003. http://tel.archives-ouvertes.fr/tel-00007407.
Vermorel, Olivier. "Étude numérique et modélisation de la modulation de la turbulence dans un écoulement de nappe chargée en particules." Toulouse, INPT, 2003. http://ethesis.inp-toulouse.fr/archive/00000004/.
Schneider, Jean. "Dynamique non-newtonienne de courants de gravité chargés en particules : Étude en régime turbulent." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0308.
Gravity currents are geophysical phenomena that occur mainly in oceanic environments. These currents have been the subject of numerous studies in the absence of particles. However, their dynamics become significantly more complex when particles are in suspension. In this thesis, we aim to characterize the dynamics of these currents in the presence of particles in multiple configurations corresponding to those found in nature. The use of new measurement techniques with high spatial and temporal resolution enables us to probe the internal structure of these currents in the case of isodense flows, and to isolate the effects of high-concentration viscosity. This technique can then be used to probe the internal structure of particle-laden gravity currents according to their buoyancy properties (sedimentation, isodensity, creaming). Finally, configurations representative of those found in nature reveal dynamics far more complex than expected. The appearance of convection effects is revealed by the study of particle-laden hypopycnal currents
Sagot, Benoît. "Contribution à l'étude du transfert thermophorétique, appliqué à l'intensification des processus de séparation gaz/particules en écoulement à phase dispersée." Compiègne, 2010. http://www.theses.fr/2010COMP1903.
The present study investigates the improvement possibilities of aerosol capture efficiency, by the use of a thermophoretic effect. The liquid particles employed for measurements have diameters ranging from a few tens of nanometers to a few microns. For these particle sizes, one can note a great disparity of the thermophoretic diffusion coefficients Kth evaluated with the various models available in the literature. The first part of this study focuses on an experimental determination of the thermophoretic diffusion coefficient, in the transition regime (values of the Knudsen number in the range 0,1 < Kn < 10), and for an average value of the gas/particle conductivity ratio close to 0,1. An original experimental device was used, which is based on an evolution of the classical penetration method. With this device, a robust determination of the thermophoretic diffusion coefficient Kth is obtained, and we have shown that the most relevant model appears to be the one proposed by Beresnev and Chernyak, while Talbot’s model led to an important overvaluation of the Kth coefficient, in the transition regime. The second part of the study relates to the analysis of the classical impinging jet configuration, which is used to study experimentally the coupling possibilities between the inertial drift and the thermophoretic migration. It is noted that for any particle-size range, a deposition improvement is obtained when increasing the hot jet/cold wall temperature difference. To identify the mechanisms which produce this intensification, a semi-analytical model was proposed. This model confirmed that the intensification observed for the fine particles is due to a thermophoretic migration. For larger particle sizes, we established that a coupling between the two drift mechanisms is operating, which produces a shift of the impactor
Rabiai, Fares. "Étude de la migration radiale de particules dans un écoulement : application à la séparation de fibres papetières et de charges minérales." Grenoble INPG, 1994. http://www.theses.fr/1994INPG0039.
Hadri, Ferhat. "Contribution à l'étude de la réduction de la traînée en écoulement turbulent d'une solution de CTAC." Phd thesis, Université de Caen, 2008. http://tel.archives-ouvertes.fr/tel-00464084.
Legrand, Alexandra. "Faisabilité technologique du traitement thermique en continu de fluides chargés en particules en utilisant trois technologies de chauffage." Compiègne, 2005. http://www.theses.fr/2005COMP1550.
The objective of this work is to substitute a discontinuous heat treatment of two heterogeneous liquid/particle foodstuffs by a continuous treatment with conventional and alternative technologies (conventional heating, direct Joule effect and indirect Joule effect). An hydrodynamic study was showed that the suspension could be described by a qualitative appreciation. A simple and fast optical method permitted to obtain the cumulative distribution of particles and to define quantitative criteria to characterize the suspension. Thermal study showed that the sterilisation of a product by a continuous processing is not interesting for the following reasons: apparatus clogging, particle degradation, phase separation, electrical and thermal instabilities related to the presence of an insulating seed coat, heterogeneous temperature profiles and low particles concentration). On the other hand, the stérilization of another product proved the feasibility of the continuous processing. They did not highlight any incidence of the heat technology on the product quality. It is thus possible to obtain products of equivalent quality to that currently present on the canned foods
Cavata, Christian. "Production de pions chargés dans les collisions noyau-noyau à des énergies comprises entre 400 et 800 Mev par nucléon." Paris 11, 1989. http://www.theses.fr/1989PA112271.
This thesis is devoted to the experimental study of pion production in relativistic heavy ions collisions. The first two chapters introduce the basic concepts and offer a review of the currently used theoretical models. The data presented were taken at the SATURNE accelerator with the DIOGENE detector (chapter III). The last part is totally devoted to our results. The data analysis is described, with an emphasis on the impact parameter selection. The pion multiplicity is systematically studied as concerns its various aspects and implications. The impact parameter, bearn energy and system size dependence are presented and compared with the results of intranuclear cascade calculation. The possibility of determining the nuclear equation of state from this comparison is discussed. The pion multiplicity distribution is consistent with a Poisson law which rules out any coherent pion production mechanism. The double differential cross-sections are then presented for large and small impact parameters. The question of pion origin in heavy ion collisions is discussed by tagging the one nucleus-nucleus inelastic collision process and the delta resonance contribution. Finally, a systematic study of pion flow is given along with a possible explanation by pion absorption in nuclear matter
Ouchene, Rafik. "Dispersion de particules non-sphériques en écoulement turbulent." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0275/document.
The present work is a part of a program research ANR PLAYER (started from January 2012), the aim of the project is to extend the simulations of gaz-particles flow to the non-spherical particles with a large range of inertia. The main objectives of this project consist, firstly, on the founding of hydrodynamic forces and torques occurring on these non-spherical particles. As results, we focus on the additional degrees of freedom that must be considered, shape effects and effects of inertia. Secondly, we are interested on the study of particle-turbulence interaction and particle-particle interaction. The aim of this Phd thesis consists on the studying of the dispersion of solide non-spherical particles in turbulent channel flow at mesoscopic scale. In order to achieve this work, we considered a one way coupling and we used a technique of Particles Lagrangian Tracking coupled with a Direct Numerical Simulation of the turbulent channel flow (DNS/PLT). This technique requires a well prediction of hydrodynamic forces and torques occurring on each particle. In addition, this technique requires a coupling of translational and rotational motions. Firstly, a Direct Numerical Simulation is used with a body-fitted method in CFD code Ansys-Fluent to simulate flow around ellipsoids. Based on the obtained results, models of correlation for hydrodynamic coeffients (drag, lift and torque) are proposed. The major results of this part is the accuracy models for a large ranges of particles Reynolds number, aspect ratio and orientations. Indeed these models take the particle Reynolds number Rep ∈ [1-240], the shape (aspect ratio w ∈ [0.2-32]) and the orientation of the particle into account. Secondly, these models of correlation as well as translational and rotational motions are implemented in the in-house DNS code. After a rigorous validation of the code using a different test cases, simulations of dispersion of ellipsoidals particles in a tubulent channel flow is performed for a moderate Reynolds number. Three main effects are investigated in this study: shape effect, inertial effect and the “effect of crossing trajectories”
Toussaint, Jean-Christophe. "Influence de l'hydrodynamique sur la déposition de particules dans un écoulement bidimensionnel." Nancy 1, 1993. http://www.theses.fr/1993NAN10029.
Thiam, Elhadji Ibrahima. "Modélisation et simulation numérique directe des transferts de chaleur dans les écoulements fortement chargés en particules." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30086.
To better characterize and understand heat transfer in fixed and fluidized beds of particles, numerical studies have been carried out in this work. Based on fully Particle Resolved Numerical Simulation (PR-DNS) local and instantaneous informations have been obtained at microscopic scale and further analyzed at macroscopic scale by means of volume and time averages. The first step consisted in a thorough validation of the numerical code on academic configurations (conduction and convection around a single particle). Then, an analysis in arrays of random fixed particles was carried out for several particle volume fractions, Reynolds and Prandtl numbers. From this analysis, the solid-fluid heat transfer was investigated at macroscopic scale and a closure model for the pseudo-turbulent heat flux was proposed. Finally, fluidized bed simulations were performed. These simulations needed a preliminary numerical study in order to select appropriate numerical parameters for accurately reproducing the fluidization with a moderate computational cost. Furthermore, a comparative study of the heat transfer in fixed and fluidized beds was carried out. The entire study aimed at improving the understanding of the heat transfer in particulate flows and dense regimes, in order to provide information for the modeling at macroscopic scale
Kouidri, Frédéric. "Etude des écoulements turbulents chargés de particules : application à l'encrassement particulaire des échangeurs à plaques corruguées." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10022.
Mongruel, Anne. "Étude expérimentale de suspensions de particules anisotropes en écoulement élongationnel." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1994. http://tel.archives-ouvertes.fr/tel-00520739.
Sanchez, Stéphanie. "Modélisation de l'injection pariétale de particules dans un écoulement turbulent." Mémoire, Université de Sherbrooke, 2004. http://savoirs.usherbrooke.ca/handle/11143/1275.
Yahiaoui, Samir. "Transport de petites particules par un écoulement de fluide visqueux." Paris 6, 2008. http://www.theses.fr/2008PA066384.
This work contributes to the study of hydrodynamic interactions between particles and wall in low Reynolds number fluid flow. Various axisymetric Stokes flows are calculated for a sphere near a plane wall. Perturbation techniques are then used to determine hydrodynamic forces, namely the viscous inertial unsteady drag force for the motion of a sphere normal to a plane wall and the lift on a sphere moving parallel to a plane wall in various ambient flow fields; regardless of the sphere to wall distance. In the lubrication regime, corrections are also derived for the approximated fluid velocity and pressure around a sphere settling normal to a wall
Desjonqueres, Philippe. "Modélisation lagrangienne du comportement de particules discrètes en écoulement turbulent." Rouen, 1987. http://www.theses.fr/1987ROUES004.
Vessaire, Jérémy. "Couplages particules/turbulence dans un écoulement tourbillonnaire et fortement ensemencé." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEN074.
Flows transporting particles are ubiquitous in natural processes (pyroclastic flow, formation of rain droplets in clouds) and industrial systems (combustion of fuel droplets in engine, industrial mixer, pollutants transport). In most practical situations, the carrier flow is turbulent. Due to the random and multi-scale nature of the turbulence structures and the various characteristics of the particles, the interactions between the flow and the particles are complex. In this thesis, we focus on highly seeded particle laden flows, when the couplings between the particles dynamics and the carrier flow are very strong. We investigate this situation in a turbulent von Kármán swirling flow, driven with a single disk rotating along a vertical axis and focus on addressing the following questions: how is the particle suspension affected by the turbulence and the mean flow, and how do particles modify the turbulence ?In a first stage, using optical diagnoses, we investigated weakly seeded flows with the aim to characterize the spatial distribution of re-suspended inertial particles on one hand and to explore the competition between suspension and sedimentation phenomena on the other hand. Then we studied the modification of turbulence intensity when increasing the volume fraction of particles from 0% to 20%. In highly seeded situations, the suspension becomes opaque and classical optical diagnostics cannot be used anymore. We have therefore developed and implemented indirect "multi-scale" measurements: (i) a global measurement of the mechanical power injected by the engine required to maintain the flow mean velocity (ii) a measurement of local pressure fluctuations to investigate the typical scales at which the flow is impacted by the particles. Through these measurements, we have demonstrated both, an effect of the effective density of the mixture on large scale and a significant redistribution of the fluctuations across scales, with non-trivial dependencies on particle diameter. These point towards a leading role of two important mechanisms related to a modified effective rheology of the turbulent suspension on one hand and to an inertial reinjection of energy at the scale of particles wake on the other hand. Finally, in order to confirm these trends, a first attempt to directly measure velocity fluctuations in highly seeded suspension by Laser Doppler Velocimetry (LDV) have been made using an optical index matched solution adapted between the fluid and the particles. This opens promising perspectives for future studies
Mongruel, Anne. "Etude expérimentale de suspensions de particules anisotropes en écoulement élongationnel." Marne-la-vallée, ENPC, 1994. http://www.theses.fr/1994ENPC9409.
Delestre, Barbara. "Reconstruction 3D de particules dans un écoulement par imagerie interférométrique." Electronic Thesis or Diss., Normandie, 2022. http://www.theses.fr/2022NORMR116.
For many industrial or environmental applications, it is important to measure the size and volume of irregularly shaped particles. This is for example the case in the context of aircraft icing which occurs during flights, where it is necessary to measure in situ the water content and the ice content in the troposphere in order to detect and avoid risk areas. Our interest has been on interferometric out-of-focus imaging, an optical technique offering many advantages (wide measurement field, extended range of sizes studied [50 μm: a few millimeters], distance particle / measuring device several tens of centimeters ...). During this thesis, we showed that the 3D reconstruction of a particle can be done from a set of three interferometric images of this particle (under three perpendicular viewing angles). This can be done using the error reduction (ER) algorithm which allows to obtain the function f(x,y) from the measurements of the modulus of its 2D Fourier transform |F(u,v)| , by reconstructing the phase of its 2D Fourier transform. The implementation of this algorithm allowed us to reconstruct the shape of irregular particles from their interferometric images. Experimental demonstrations were carried out using a specific assembly based on the use of a micro-mirror array (DMD) which generates the interferometric images of programmable rough particles. The results obtained are very encouraging. The volumes obtained remain quite close to the real volume of the particle and the reconstructed 3D shapes give us a good idea of the general shape of the particle studied even in the most extreme cases where the orientation of the particle is arbitrary. Finally, we showed that an accurate 3D reconstruction of a "programmed" rough particle can be performed from a set of 120 interferometric images
Fohanno, Stéphane. "Contribution à l'étude des collisions entre particules et des interactions particules-parois en écoulement gaz-solide, par voie expérimentale et simulation lagrangienne." Nancy 1, 1997. http://www.theses.fr/1997NAN10261.
The aim of the present work is to bring experimental and numerical contributions to the knowledge of the effects of collisions between particles in gas-solid flows. A Lagrangian simulation, using a probabiIistic model to take particIe-to-particle collisions into account is used. The first chapter consists in a review of previous works on these collisions and on particle-wall interactions in gas-solid suspension flows. The second chapter explains the development of an original experimental facility allowing the investigation of a gas-solid flow, in a vertical convergent channel, where effects of collisions between particIes are preponderant. Then, the third chapter describes the photographic technique of visualization and the image analysis method. Experimental results (Chapter IV) obtained for two mass flow rates of spherical glass beads (3mm in diameter) show the influence of collisions between particles on the evolution of the characteristics of the flow (velocity and concentration profiles). This experimental work is completed with measurements of particle-wall interactions characteristics (restitution and friction coefficients, roughness parameter) in our experiments. Next, the study of the influence of each parameter used to model particle-wall interactions and particle-to-particle collisions in the Lagrangian simulation is realized in chapter V. Finally, experimental resuIts are compared with predictions of this simulation (Chapter VI). The relevancy of using a probabilistic model to take collisions between particles into account is shown. An improvement of this model has been proposed. Nevertheless, it still needs to be improved. Departure from sphericity of the particles should also be modelled to get better predictions
Baraglia, Federico. "Développement d'un modèle triphasique Euler/Euler/Lagrange pour la simulation numérique des écoulements liquide-gaz chargés en particules." Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSEP017.
This manuscript sums up work carried out during a thesis at the MFEE department of EDF R&D on liquid-gas flows laden with dispersed particles under the supervision of Olivier Simonin (IMFT), Jérôme Laviéville (EDF), and Nicolas Mérigoux (EDF). The thesis aims at providing a working environment for the numerical simulation of two-phase bubbly flows, free-surface flows or in a mixed regime, loaded with particles that can interact with the fluids present in their continuous or dispersed form. These flows can be found in industrial situations such as chemical reactors, power plants, or wastewater treatment plants, as well as in natural situations such as during a flood. The developed tool allows predictions to be made about the performance of these industrial devices or the damage caused by exceptional natural events. The developments are included in the most up-to-date version of neptune_cfd, a multi-fluid solver developed by EDF, CEA, IRSN, and Framatome, based on the standard multi-fluid method that allows the simulation of multiphase flow independently of their typology.The methods implemented are based on well-known two-phase approaches. The stochastic Lagrangian particle tracking method is adapted so that each particle can interact with all the fluids. Closures are proposed to determine the impact of each phase on the behavior of the particles. To verify certain assumptions, a new closure for the Langevin equation on the fluid velocity seen by the particle is proposed. Its behavior is compared to standard models and literature on simple verification cases of homogeneous isotropic turbulence and inhomogeneous cases. The Lagrangian equations obtained are used to close an Eulerian model based on the probability density function approach. The performance of the two developed threephase models is established in terms of particle deposition driven by turbulence or gravity.A significant part of the thesis focuses on an issue that arose during preliminary checks: the phenomenon of air entrainment in plunging jets. Indeed, due to the nature of the solver, bubbles or dispersed droplets can detach from the free-surface depending on the flow conditions. The quantity of these transferred structures and their characteristic size being crucial quantities which drives their behavior, a new model had to be developed. Mass transfer between continuous structures and dispersed inclusions is ensured by the model that describes the evolution of resolved interfaces, the latter was not modified. The one regarding the size of the created bubbles/droplets is integrated into the evolution equation of the interfacial area, a quantity that allows tracking the diameter of the inclusions.All developed models are compared to experimental measurements. The air entrainment model is first tested without the presence of particles in various cases. A hydraulic jump case is also considered to establish the generality of the model. Then, the threephase models are tested in various configurations. First, configurations without air entrainment to isolate the behavior of the particles, and then with air entrainment. The different cases highlighted the importance of certain models and the differences between stochastic Lagrangian and Eulerian methods
Benoit, Hadrien. "Récepteur solaire tubulaire à suspension dense de particules en écoulement ascendant." Thesis, Perpignan, 2015. http://www.theses.fr/2015PERP0045/document.
This thesis, financed in the frame of the CSP2 European project, concerns the study of a new kind of thermal concentrating solar receiver using a dense suspension of solid particles circulating upward in vertical tubes. The suspension is obtained by fluidizing Geldart A-type particles. The principle consists in creating an upward flow of the suspension in a vertical tube exposed to the concentrated solar radiation that heats the tube wall. The heat is then transmitted to the particles circulating inside that transport it to a conversion cycle for electricity production. Contrarily to usual solar heat transfer fluids, particles can reach high temperatures (> 700 °C) that permit to power high efficiency thermodynamic cycles such as Brayton or combined cycles. Moreover they can be used as a direct heat storage medium for continuous electricity production. During this thesis, a one-tube solar receiver was successfully tested at the PROMES-CNRS solar furnace in Odeillo, with particle outlet temperatures of 750 °C reached. The first values of wall-to-suspension heat transfer coefficient were calculated and a Nusselt correlation was determined. A specific flow pattern with a particle downward flux close to the wall and upward flux in the tube center was underlined. The flow hydrodynamics and the heat transfer mechanisms were studied thanks to 3D numerical simulations. A 16-tube 150 kWth receiver was finally tested and modeled, proving the process applicability at larger scale
Condoret, Jean-Stéphane. "Etude des transferts en écoulement pulsé dans un lit de particules." Toulouse, INPT, 1987. http://www.theses.fr/1987INPT011G.
Kellil, Amara. "Caractéristiques morphologiques des particules floculées : influence des conditions hydrodynamiques de formation." Toulouse, INPT, 1989. http://www.theses.fr/1989INPT025H.
Baldaccini, Daniel. "Analyse par caméra C. C. D. Du comportement hydrodynamique et de l'instabilité d'un jet chargé en particules solides." Aix-Marseille 1, 1990. http://www.theses.fr/1990AIX11295.
Madsen, Alexander. "À la recherche d'un boson de Higgs chargé impliquant des signatures leptoniques à l'aide de l'expérience ATLAS." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAY043/document.
This thesis presents searches for a charged Higgs boson (H+) in proton-proton collisions with center-of-mass energies of 7 TeV and 8 TeV, using data collected by the ATLAS experiment at the CERN Large Hadron Collider. Multiple search channels are used with a common characteristic of at least one charged lepton (electron or muon) that effectively reduces the multi-jet background and is used for efficient triggering.Charged Higgs bosons decaying to a tau lepton and a neutrino are searched for using final states with two charged leptons or one charged lepton and a hadronically decaying tau. A significant background originates from quark- and gluon-initiated jets that may be misidentified as hadronic tau decays. Methods to estimate this background are developed, including a largely data-driven matrix method. Signal processes with a charged Higgs boson mass below or above that of the top quark are considered. With the dataset collected at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3/fb, upper limits at 95% confidence level are placed on the branching fraction Br(t -> bH+)*Br(H+ -> tau nu) in the range 1.1-0.3% for charged Higgs boson masses between 80 GeV and 160 GeV, and on the top-quark associated charged Higgs boson production cross section in the range 0.53-0.04 pb for charged Higgs boson masses between 180 GeV and 1 TeV
Saldo, Valérie. "Etude du dépôt d'aérosols dans des conduites en écoulement fortement turbulent." Aix-Marseille 1, 1996. http://www.theses.fr/1996AIX11060.
Bounhoure, Corinne. "Étude d'écoulements fluide-particules hors du régime de Stokes." Lille 1, 2003. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/1a4faab6-871f-4496-9638-ff0df8de2bfc.
Konan, N'Dri Arthur. "Modélisation numérique stochastique des rebonds de particules sur parois rugueuses." Phd thesis, Toulouse, INPT, 2007. http://oatao.univ-toulouse.fr/7656/1/konan.pdf.
Dbouk, Talib. "Rhéologie des suspensions concentrée et migration des particules induite par un écoulement." Phd thesis, Université Nice Sophia Antipolis, 2011. http://tel.archives-ouvertes.fr/tel-00673964.
Jamais, Sylvain. "Contribution à l’étude de la dispersion de particules par un écoulement turbulent." Grenoble INPG, 2000. http://www.theses.fr/2000INPG0009.
We present here the study we have conducted on a gaseous turbulent jet loaded with solid particles or liquid droplets. This study is performed in the framework of the collaboration between the Cemagref and industrial partners. The final aim of our work is the transfer to our industrial partners of a maximum of useful knowledge for the development and improvement of their products. Therefore we have tried to perform the most complete study. We also had the commitment to produce utilizable results and to use and develop study techniques likely to be adopted by the partners at the end of our collaboration. Our study focuses on the dynamic side of the flow. Furthermore we have built a reduced-scale model with smaller flow rates and therefore smaller flow range. The use of this scaled model enabled us to design an indoor laboratory experimental facility where we control exactly the conditions in which the flow operates. This report consists of three parts. The first one presents the fundamentals for the phenomena that govern dispersed two-phase turbulent flows. Then we review the state of the art for the knowledge and study techniques for such flows. In the second part we detail the experimental part of our study, the techniques we used and the results we have obtained. Then the third part presents the work performed for the development of a numerical prediction tool, where from we started, the models we reviewed to account for the physics involved in the flows and give an outline of the first results
Nasani, Ahmad Muntaser. "Etude des phénomènes électrofluidodynamiques sur les gaz empoussiérés en écoulement turbulent : application au transport pneumatique." Poitiers, 1987. http://www.theses.fr/1987POIT2307.
Ouriemi, Malika Ouerda Sandrine. "Erosion, transport et instabilités d'un lit de particules dans un tube." Aix-Marseille 1, 2007. http://www.theses.fr/2007AIX11045.
Hajji, Lotfi. "Contribution à l'étude des effets inertiels sur le comportement de particules en suspension dans un écoulement gazeux turbulent." Nancy 1, 1995. http://www.theses.fr/1995NAN10014.
Machicoane, Nathanaël. "Particules matérielles en écoulement turbulent. Transport, dynamique aux temps longs et transfert thermique." Phd thesis, Ecole normale supérieure de lyon - ENS LYON, 2014. http://tel.archives-ouvertes.fr/tel-01070651.
Horgue, Pierre. "Modélisation multi-échelle d'un écoulement gaz-liquide dans un lit fixe de particules." Thesis, Toulouse, INPT, 2012. http://www.theses.fr/2012INPT0024/document.
We study in this work the modelling of two-phase cocurrent downflows in fixed bed reactors, a process widely used in industry. Due to the flow complexity, i.e., the presence of different interface configurations and, therefore, different phase interactions, most models have been developed using empirical approaches, with the assumption of a homogeneous flow in the reactor. However, several studies showed that local heterogeneities, geometric and hydrodynamic, such as the liquid distribution, could have a great influence on the flow at the reactor-scale and, therefore, on the reactor performance. Consider the microscopic phenomena in a macroscopic model require the use of multi-scale approaches. However, due to the flow complexity, the upscaling cannot be done directly and requires the development of modelling tools suitable for an intermediate scale. In a first step, the direct numerical method \ Volume-Of-Fluid" (VOF) is validated in the case of a two-phase flow in a capillary tube with the presence of a thin film. Then, this method is used, at a microscopic level to propose and validate closure laws for a pore-network model which will be used to simulate the flow at the intermediate scale. This upscaling approach is first tested in a two-dimensional case,i.e., an array of cylinders between two walls. This configuration allows the set up of an experimental approach, coupled with 2D VOF simulations at the intermediate scale, in order to validate the pore-network approach. The pore-network approach is then extended to a real fixed bed, i.e. in three dimensions, whose geometry is obtained by micro-tomography. Local laws of the pore-network model are redefined using direct numerical simulations at a microscopic scale. Pore-network simulations are then compared, for a homogenous phase distribution, with 1D models typically used for two-phase flow in fixed beds. Finally, an experimental campaign was set up to observe, by imaging scanner, the spreading of a liquid jet on a fixed bed pilot. A qualitative comparison is then performed between experimental observations and pore-network simulations in the specific case of the spreading of a liquid jet
Makhoul, Mounia. "Modélisation du transport de particules dans un écoulement de Stokes à effet cliquet." Thesis, Avignon, 2016. http://www.theses.fr/2016AVIG0507/document.
The work presented in this Phd Thesis is the modelling of particle transport in a Stokes flow taking into account the characteristics of the particle, the regime flow, and the effect of the confinement which could be related for example to the consideration of a porous media structure. The phenomena of the transport is based on the mecansim of ratchet effect which appears when the system is undergoes an alternative pumping. The study of the particle dynamics is performed using the continuation method which allows to follow the periodic solutions according to the desired parameter, to identify the types of bifurcation and critical points. This study requires the knowledge of the drag force exerted on the particle and which we compute using the boundary integral equation
Henry, Christophe. "Modélisation stochastique du dépôt de particules colloïdales sur des parois rugueuses dans un écoulement turbulent." Paris 6, 2012. http://www.theses.fr/2012PA066209.
The aim of this PhD work is to develop physical models aiming at simulating particulate fouling (i. E. The accumulation of inorganic colloidal particles on surfaces) in turbulent flows in the framework of stochastic Lagrangian methods. In the first part, a new model for the calculation of particle-surface interactions including the effects of surface roughness is presented. This model is first validated on simple test-cases and the influence of surface roughness on the overall interaction is analysed. This model is then coupled with a model for particle transport in a turbulent flow. Numerical results obtained for particle deposition are found to be in line with measurements. The second part of this work is devoted to the extension of the particle-surface interaction model for the calculation of adhesion forces, accounting for both surface roughness and electrostatic forces. Numerical predictions are in good agreement with experimental data on adhesion forces. Furthermore, this model is coupled with a model for particle resuspension and numerical results obtained are shown to compare well with some available experiments. In the third part of this work, the particle deposition model is extended to simulate the accumulation of particles on a surface through the introduction of particle-particle interactions in the particle-surface interaction. Numerical results are in qualitative agreement with available experimental data, and highlight the ability of the model to reproduce a complete blockage. This study underlines the necessity to account for the coupling between particle-fluid, particle-surface and particle-particle interactions to simulate particulate fouling
Combe, Laure. "Simulation numérique d'écoulements gaz-particules sur maillage non structuré." Toulouse, INPT, 1997. http://www.theses.fr/1997INPT133H.
Michielsen, Nathalie. "Étude du dépôt des aérosols par thermophorèse dans un écoulement laminaire." Paris 12, 1990. http://www.theses.fr/1990PA120025.
Merhi, Dima. "Migration et ségrégation des particules dans les suspensions concentrées : étude expérimentale et modélisation." Nice, 2001. http://www.theses.fr/2001NICE5652.
In this present work, we have studied the behavior of concentrated macroscopic suspensions subjected to inhomogeneous shear rate. This behavior was described by means of a local phenomenological approach based on the consideration of the suspension as a continuous medium. Three shear induced fluxes were identified : a collision flux, a viscosity flux and a curvature flux. The expression of these three fluxes is obtained by studying the deviation of the trajectory of pairs of particles induced by a collision. We achieved both experimental and numerical investigations. On the experimental plan, we studied the flow between two parallel rotating disks. We developed an experimental technique which leans on the detection of tracers by measure of absorption of the light. The studied systems are suspensions established by particles of the same refractive index and the same density as the suspending fluid. Concerning the numerical work, we have built a numerical code in 2D, based on a finite volume method, capable of modeling the system of coupled non linear equations which govern the behavior of a monodisperse or bidisperse suspension. So we studied numerically the behavior of a bidisperse suspension in a Couette and a Poiseuille flow. We observed segregation in size of particles in suspension which is more pronounced when the volume fraction of the small and big particles is nearly equal. In the case of the flow between two rotating discs, we put in evidence the existence of a migration for a monodisperse suspension. The quantification of the coefficients of the shear induced migration fluxes in the rotating geometries was made thanks to the numerical, transient profiles. The values so obtained show that the intensity of these fluxes is closely bound to the direction of the migration of particles
Rambaud, Patrick. "Contribution à l'étude du comportement de particules solides en écoulement turbulent confiné par simulation numérique directe." Nancy 1, 2001. http://www.theses.fr/2001NAN10204.
The behavior of solid particles in a turbulent gas channel flow is studied by direct numerical simulation. A mixed Eulerian and Lagrangian formulation allowed us to deal with the dispersion of small solid particles through the computation of the integral time scales of the turbulence seen by the solid particles on their trajectories. Those integral times are compared with the ones estimated thank to a semi-empirical correlation established with direct numerical simulation in isotropic and homogeneous turbulence. The comparison shows the impossibility to use this correlation to predict the streamwise dispersion. Beside this dispersion study, the turbulence modulation due to solid particles is shown. The forces taken into account on the particles in all the simulation are at least the non-linear drag and the Saffman's lift both corrected for near wall effect and using a fully three-dimensional Hermitian interpolation
Mingalev, Stanislav. "Le Comportement de la bulle et des particules, l’écoulement pulsatile et le flux péristaltique." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0361/document.
The thesis studies the peristaltic flow of fluid in a channel with the specified pressure wave at the boundary. The law of wall’s coordinate variation isn’t determined a priori. It is found from the initially definite law of pressure-variation on the wall. This way is based on the fact that some hollow organs change diameter under the signals of baroreceptors (sensors that detects the pressure). We studied the effects of various parameters on flow rate and structure of flow. Besides we studied the influence of vibration on the peristaltic flow under long wave approximation. The paper also considers the influence of the wall transverse pulsation on the fluid transport under the pressure drop. This problem arises in defining the liquid viscosity by squeezing flow viscometry. The same problems occur in analyzing different biological systems, including the lubricant movement in joints or in the microvessels of working muscles. The influence of sound on the interaction of a solid particle and a gas bubble in fluid is studied as well
Abbas, Micheline. "Auto-diffusion de particules dans un écoulement cisaillé : des interactions hydrodynamiques aux effets collisionnels." Toulouse, INPT, 2008. http://ethesis.inp-toulouse.fr/archive/00000622/.
Lagrangian simulations are used to study the rheophysics of sheared suspensions of spherical particles. The effects of the fluid inertia, the Brownian diffusion and the gravity are neglected. Depending on the particle inertia characterized by the Stokes number, the suspensions are divided into two major classes. The limit of vanishingly small Stokes numbers corresponds to solid particles suspended in a very viscous fluid. The "Force Coupling Method" is used to model the direct hydrodynamic interactions controlling the dynamics of these monodisperse suspensions. This method is based on a finite multipole expansion of the velocity field perturbation induced by each particle. The motion of all the suspension particles is simultaneously coupled through the direct solution of the Stokes equations written for the carrying fluid flow. The macroscopic evolution is studied while the solid volume fraction is increased from low to moderately concentrated [φ=1-20%]. The results (velocity fluctuation, self-diffusion, velocity auto-correlation and spatial distribution of pairs. . . ) are in agreement with several former studies of the literature. We showed that the particle agitation is enhanced by increasing the concentration and leads to a diffusive behavior of the suspension. The agitation level and the characteristic diffusion time are increasing as many-body hydrodynamic interactions control the suspension dynamics. The accuracy of the method is improved by calculating the exact lubrication forces for particle pairs near contact. Hence, this allows to simulate larger suspension concentrations (up to 35%), and to quantify the effective viscosity in this regime. The model is extended to the bidisperse suspension configurations. The dependence of the statistical quantities (of both species) on the size ratio and concentration ratio is discussed for a fixed total volume fraction. For a constant concentration ratio, we obtained that an increase of the size ratio enhances (resp. Reduces) the fluctuation level of the small (resp. Large) particles. The increase large particle number induces a significant enhancement of the fluctuations and self-diffusion of both species. The suspensions characterized by moderate to high Stokes numbers are generally of gas-solid type. A hard-sphere collision model coupled with the particle Lagrangian tracking is used to simulate the suspension dynamics. The particle motion is controlled by only the drag force and particle collisions. The simulations show that the suspension properties depend strongly on the particle inertia and concentration. Increasing the Stokes number from 1 to 10 induces an enhancement of the suspension agitation by three orders of magnitude, and an evolution of the velocity distribution function from a highly peaked (close to the Dirac delta function) to a Maxwellian shape. The numerical results are compared to the predictions of two theoretical models based on the kinetic theory of granular flows adapted to moderate inertia regimes. The velocity distribution used for weakly (resp. Highly) agitated suspensions is the Dirac delta (resp. Deviated Maxwellian) function. A new prediction of the Lagrangian self-diffusion tensor is proposed and validated by the simulations results. The diffusion coefficients and solid phase viscosity are compared to the classical models used in engineering applications. The inelasticity effect on the statistical quantities is discussed as well. The conclusion of the manuscript proposes a unified approach of all the results related to the evolution of the effective viscosity in the bulk. A modification of the Force Coupling Method is proposed to properly simulate the particle inertia and hydrodynamic effects
Hamelin, Patrice. "Application de la diffusion lumineuse à la métrologie des particules en écoulement diphasique dispersé." Toulouse, INPT, 1986. http://www.theses.fr/1986INPT059H.