Дисертації з теми "Méthode de description libre"
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Aljer, Ammar. "Co-design et raffinement en B : BHDL tool, plateforme pourr la conception de composants numériques." Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-Aljer.pdf.
Повний текст джерелаHanaei, Farnaz. "De la caractérisation sensorielle vers la caractérisation instrumentale de la texture. Une étude de cas sur les produits modèles à base de lait." Electronic Thesis or Diss., Paris, AgroParisTech, 2015. http://www.theses.fr/2015AGPT0018.
Повний текст джерелаIn our study the texture of a set of model processed cheeses is characterized through both sensory and instrumental approaches. Three objectives guided our work. The first was using an individual approach that takes the diversity in terms of perception, manipulation and description into account for sensory characterization of products. Furthermore, to study the effect of prior expertise, two panels evaluated the products: consumer and expert panel. A combined approach with two different methodologies and verbalization (Free comment followed by Flash Profile) made it possible to identify specificities in the answer behavior between the two panels. Free comment showed the similarity and differences between the terminologies of two panels. It showed that experts generate more terms in average than consumers. However, some of their terms are specific and never was cited to consumers. Flash profile showed that there are some characteristics that become important once the assessors evaluate the products simultaneously. The result showed important differences between the resulted product maps from consumers and experts after free comment method. However, the resulted sensory maps after the Flash Profile were very similar for both panels and were close to the sensory map obtained for consumer panel after free comment. Some specific attributes were frequently cited for products evaluations in two applied methods, such as “Collant (Stickiness)”.The second objective was to establish the instrumental characterization on the basis of sensory results in order to better determine some efficient methodologies and conditions to characterize the identified perceptions. We thus used sensory descriptions and observations to choose appropriate instrumental methods. On this basis, classic rheological methods (measurement of the viscoelastic properties and penetrometry) and adapted tack method were used for product characterization. Furthermore, the products were characterized at two physical states (without or after a mechanical treatment). The adapted tack method and the rheology at small deformation with vane geometry permitted to characterize the products set with important texture diversity (solid, semi-solid, liquid). The results showed that the combination of two methods improves the product map and brings new axes of description. The instrumental characterization of mechanically treated products did not lead to a rather different products configuration.The third objective was to predict the sensory positioning of products (product map) as well as the specific multidimensional perception “Collant (Stickiness)”, by instrumental measurements. A rather satisfactory prediction of consumer perception of texture was obtained through viscoelastic measurements (storage module and yield stress) and parameters stemming from tack measurement (total energy and distance at maximum tensile force). Furthermore, the sensory perceptions relative to “Collant (Stickiness)” is well predicted by the instrumental parameter “yield stress” for the majority of the consumers who applied this term in their evaluations
Ata, Riadh. "Écoulements à surface libre avec la méthode SPH." Mémoire, École de technologie supérieure, 2002. http://espace.etsmtl.ca/821/1/ATA_Riadh.pdf.
Повний текст джерелаTchissambot-Goma, Urbain. "Description thermodynamique du système fer-zinc." Lille 1, 1988. http://www.theses.fr/1988LIL10004.
Повний текст джерелаWack, Maxime. "Méthode de description de réseaux locaux industriels hétérogènes." Compiègne, 1991. http://www.theses.fr/1991COMPD419.
Повний текст джерелаChkir, Saïd. "Contribution àl'étude aérodynamique d'une éolienne par une méthode de sillage libre." Paris, ENSAM, 2010. http://www.theses.fr/2010ENAM0025.
Повний текст джерелаThis thesis presents a method for calculating the unsteady three-dimensional flow around a wind turbine rotor. The real flow is replaced by a free stream past a vortex model of the rotor. This model consists of lifting vortex lines which replace the blades and a trailing free vorticity. For simplicity the vorticity shed from the blade trailing edge is concentrated in two vortices issued from tip and root. To compute the resulting flow and to evaluate the unsteady forces exerted on the rotor, a free wake method is used. This method consists of a Lagrangian representation of the flow field. The evolution of the wake downstream of the rotor is obtained by tracking the markers representing the vortices issued from the blade tips and roots. To solve the wake governing equation and to obtain the marker positions, a time-marching method is applied and the solution is obtained by a second order predictor-corrector scheme. The free wake methods are usually inviscid, but in the present approach, the viscous effects are taken into account. It is supposed that the induced velocity on vortex line is limited by a maximum velocity in the viscous vortex core. The diffusion of the vortex lines and the vortex core growth are supposed to depend on vortex age. All constants needed to represent the viscosity effects are extracted from experiments. To validate the proposed method a comparison is made with experimental data obtained in the case of a model of wind turbine where the flow field immediately behind the rotor is measured by means of particle image velocimetry (PIV). It is shown that the numerical simulation captures correctly the near wake development
Zouaoui, Driss. "Equilibre des liquides magnétiques avec interface libre." Vandoeuvre-les-Nancy, INPL, 1991. http://www.theses.fr/1991INPL022N.
Повний текст джерелаDoring, Mathieu. "Développement d'une méthode SPH pour les applications à surface libre en hydrodynamique." Nantes, 2005. http://www.theses.fr/2005NANT2116.
Повний текст джерелаRecent development in numerical methods together with the increase of computational power available have allowed simulations of more and more complex flows. However interfacial flows remains a difficult task, especially when breaking, interface reconnection or impacts occurs. Theses difficulties arise mainly from the deformations of the computational domain during the simulation which are badly handled by mesh based Eulerian numerical methods. Smoothed Particle Hydrodynamics, being meshless and Lagrangian allows a simplified management of the interface. In this PhD a SPH based numerical methods has been developed in order to simulate complex free surface flows with impacts and huge breaking. A particular care was taken concerning increasment of the precision; thus different discretization schemes have been tested (Moving Least Square, Renormalisation) as well as boundary conditions (frozen particles, ghost particles) were implemented and tested. Comparison of obtained results with both experimental results and numerical simulations from different numerical methods (Volume of Fluid_Finite volume solvers, spectral potential solver) in development in the Fluid Mechanics Laboratory in a variety of test cases as dam breaking, sloshing in a tank, virtual bassin, impact of solid through free surface shows good agreement, confirming the potential of the SPH method in naval hydrodynamics. The development of an original and new method allowing the obtention of loads on solid boundary made us able to compute loads exerted on an obstacle in a dam breaking test case and to simulate impacts of a wedge in free motion with favourable comparison against experimental dynamic conditions in both configurations. Moreover, a work on parallelization of the code has been carried out, firstly in a data decomposition approach (OpenMP) which we gave up due to its poor efficiency. Then a domain decomposition method was implemented using MPI library and showed good results concerning speed-up in various configurations (PC cluster, SuperComputer) thanks to the overlapping of communication time by standard SPH serial operations. Finally the use of a Verlet like algorithm for neighbor search allowed the optimisation of computationnal efficiency. Thanks to code organisation, three dimensionnal simulations are possible with minimum adaptation
Quemar, Pierrick. "Modélisation et analyse numérique des écoulements à surface libre." Thesis, Paris 13, 2019. http://www.theses.fr/2019PA131022.
Повний текст джерелаIn this thesis, we are interested by Finite Elements methods for the three-dimensional free surface Navier–Stokes equations under the ALE formulation. They enable to simulate geophysical flows. The initial and main goal is to analyse the existing limitations of these numerical methods and to provide perspectives of improvement, justified mathematically.This purpose helps us to present a review and improvement way for Telemac-3D, which is a hydrodynamics industrial software developed by the Laboratoire National d’Hydraulique et Environnement of EDF R&D. Therefore, we analyse precisely and we evaluate this algorithm, with respect to the recent scientific publications. This software solves the free surface Navier–Stokes equations with the decomposition of the pressure through a hydrostatic part and a dynamic part. A major limitation is that the velocity field of the fluid is not divergence-free. Furthermore, we highlight a time restriction on the time step. Moreover, alternative approaches are studied and compared. In particular, we focus on a numerical strategy which consists in advecting the free surface, in updating the domain and in solving the Navier–Stokes equations. Based on this strategy, we analyze a first order explicit scheme in time with a Finite Elements stabilization term. The numerical method allows to ensure important properties : the mass conservation of the water quantity and the weak free divergence condition. We demonstrate that this scheme is conditionally stable in time. Besides, we propose a new variational formulation allowing to obtain a semi-implicit scheme in time combined with the Finite Elements method,which is stable independently from the velocity of the mesh and without an exact free divergence velocity.Finally, in order to expand the hydrodynamic knowledges, some simplified models used in other software developed by EDF R&D are studied. In particular, we focus on the mild-slope equation solved in the software Artemis [51]. It is an asymptotic model derived from the linear water wave equation. As a consequence, we study the hypothesis and the validity of the derivation. An approximate analytical solution is additionally derived for this purpose. Moreover, comparisons with other asymptotic models, such as the linear shallow water equation or the Helmholtz equation, are presented
Cherfils, Jean-Marc. "Développements et applications de la méthode SPH aux écoulements visqueux à surface libre." Phd thesis, Université du Havre, 2011. http://tel.archives-ouvertes.fr/tel-00607041.
Повний текст джерелаOger, Guillaume. "Aspects théoriques de la méthode SPH et applications à l'hydrodynamique à surface libre." Nantes, 2006. http://www.theses.fr/2006NANT2118.
Повний текст джерелаHeniche, Mourad. "Modélisation tridimensionnelle par éléments finis d'écoulements à surface libre." Compiègne, 1995. http://www.theses.fr/1995COMPD801.
Повний текст джерелаBreas, Marielle. "Problématique de l'intégration de l'action individuelle dans les systèmes technologiques : application : utilisation de la description des fonctions pour favoriser l'autonomie." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL158N.
Повний текст джерелаMarongiu, Jean-Christophe. "Méthode numérique lagrangienne pour la simulation d'écoulements à surface libre : application aux turbines Pelton." Ecully, Ecole centrale de Lyon, 2007. http://bibli.ec-lyon.fr/exl-doc/TH_T2325_jmarongiu.pdf.
Повний текст джерелаThe SPH (Smoothed Particle Hydrodynamics) method is a meshless numerical method used in this study to spatially discret ize fluid mechanics equations ( mostly 'Euler equations). Sin ce few years, SPH is becoming successfull in simulating free surface flows thanks to its lagrangian formalism , which eases the handling of interfaces. This study aims at applying this method to simulate free surface flows as those happening in Pelton turbines. The standard SPH formalism is first tested. This validates the feasability of using SPH for this application but also underlines the weaknesses of the standard method, notably in terms of accuracy and reliabili ty. A hybrid formulation called SPH-ALE (Arbitrary Lagrange Euler) has then been chosen. This method has many similarities with the Finite Volume method. Indeed it uses the conservation form of flow equations and is theoretically able to handle properly any smooth transport field of the discretization points. In addition, from a purely numerical point of view, the SPH-ALE formalism allows a proper use of upwind numerical schemes, and in particular Godunov and higher order schemes. In practice, this hybrid method behaves better than the standard one for the targeted applications. Stability and accuracy of the simulations are greatly improved. In particular the pressure field can be correctly predicted without resorting to any numerical smoothing. . The introduction of boundary conditions is also easier with the hybrid method. Whereas this is one major challenge for the standard SPH method, SPH-ALE can handle boundary conditions through boundary fluxes which can also be computed in an upwind fashion. The setting of a consistent and rigorous boundary treatment is the main contribution of this study. The SPH-ALE method is tested and validated on typical cases, giving satisfacory results, particularly for the pressure field on solid boundaries. To conclude, developments presented in this study have been driven by the targeted application in Pelton turbines. The need for a proper handling of bodies with complex shapes and the requirement of accuracy have lead to a focus on the hybrid SPH-ALE method. This work opens the door to promising perspectives and quick developments thanks to the strong link with the Finite Volumes method
Marcou, Olivier. "Modélisation et contrôle d’écoulements à surface libre par la méthode de Boltzmann sur réseau." Perpignan, 2010. http://www.theses.fr/2010PERP1001.
Повний текст джерелаThis PhD work considers the general problem of modelling and simulation of complex systems and deals with the domain of control and management of water resources. We propose here an original approach based on Lattice Boltzmann models (LB) for modelling free surface flows in irrigation canals, usually described with the non-linear shallow water equations. We adapted a bi-fluid model and studied the boundary conditions which allow to reproduce the geometry of a free-surface irrigation canal. Methods for estimating the desired hydraulic quantities were developed. We studied the behavior of submerged underflow gates, and we show that the model is able to spontaneously and correctly describe how the gates function in quite different situations. Validations were realized by comparing results from simulations and experimentations performed on a laboratory micro-canal facility. We also introduced sedimentation phenomena in the model and studied the influence of a sedimentation deposit on the flow. Comparisons between experimental and simulation results were also performed and converged
Kerrami, E. H. "Description des résonances géantes nucléaires par la méthode de la coordonnée génératrice." Doctoral thesis, Universite Libre de Bruxelles, 1993. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212808.
Повний текст джерелаBouttes, François. "Simulation numérique des écoulements à surface libre avec turbulence." Compiègne, 1994. http://www.theses.fr/1994COMPD715.
Повний текст джерелаKadiri, Anass. "Études analytique et numérique 2D et 3D de la convection mixte d'un fluide binaire sous effet Soret et soumis à des conditions hydrodynamiques Libre-Libre et Rigide-Libre." Amiens, 2013. http://www.theses.fr/2013AMIE0117.
Повний текст джерелаThis work deals with the analytical and numerical study of heat and mass transfer in mixed convection with Soret effect of a binary fluid subjected to free-free and rigid-free hydrodynamic conditions. We consider a parallelepiped box filled with a Boussinesq binary mixture. Horizontal boundaries are perfectly heat conducting and subjected to constant temperatures; with highest temperature on the bottom; the lateral walls are adiabatic. A through flow is imposed on the other vertical bounds. The fluid enters from one side and exits from the other. The liquid layer is subjected respectively to free-free and rigid-free conditions on the horizontal bounds. The study focuses on linear stability analysis, leading to general dispersion equation, and explicit relation between Rayleigh, Reynolds, Lewis, and Prandtl numbers, and also the buoyancy rate, the wave number and the pulsation. A second part focuses on 3D numerical simulations based on finite volume method. It is found that, the mixed convection in free-free case is not a Galilean transformation because of advection phenomena. The main difference with natural convection is the absolute instabilities. Comparison with numerical results shows good agreement especially when non-linearity's are weak. The propagation of transverse waves was studied in details. In the rigid-free case, the effect of the hydrodynamic boundary layer partially and fully established on convective structures was examined
Andrillon, Yann. "Simulation d'écoulements à surface libre par une méthode de capture d'interface en formulation totalement couplée." Nantes, 2004. http://www.theses.fr/2004NANT2019.
Повний текст джерелаZhang, Bainian. "Modélisation d'écoulements à surface libre avec fronts mobiles par éléments finis." Compiègne, 1992. http://www.theses.fr/1992COMPD500.
Повний текст джерелаHils, Martin. "Fusion libre et autres constructions génériques." Phd thesis, Université Paris-Diderot - Paris VII, 2006. http://tel.archives-ouvertes.fr/tel-00274128.
Повний текст джерелаla fusion libre sur une fusion fortement minimale est effectuée. Puis, des variations sur le thème de la fusion sont étudiées (courbe générique et structures bicolores). À titre d'exemple, il suit des résultats que l'on peut donner un sens à la notion d'une courbe générique dans un corps pseudofini. Enfin, l'axiomatisabilité de l'automorphisme générique est démontrée dans certains contextes issus d'une amalgamation à la Hrushovski dont la fusion libre et les théories des différents corps bicolores de Poizat (noir, rouge et vert).
Benayed, Miloud. "Extensions centrales : quantification géométrique et méthode des orbites." Lille 1, 1996. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1996/50376-1996-45.pdf.
Повний текст джерелаNouri, Nowrouz Mohammad. "Dynamique du tourbillon dans un écoulement potentiel avec surface libre." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL105N.
Повний текст джерелаCondaminet, Vincent. "Identification par méthode inverse des coefficients aérodynamiques d'un projectile à partir de l'observation de son vol." Caen, 2016. http://www.theses.fr/2016CAEN2032.
Повний текст джерелаAccurate knowledge of the aerodynamic behavior of a projectile is primordial for safety and efficiency reasons in operational situation. The determination of the aerodynamic coefficients of a projectile can be made from in-flight recorded data. In this study, the proposed identification process is automatic, robust with respect to the measurement noise, and it allows the reduction of the cost of the flight tests. It consists in searching for the couple composed of state parameters and aerodynamic coefficients which satisfies the flight equations and leads to a trajectory the close to the recorded data. This leads to solve a non linear optimization problem under equality constraints. Several versions of the identification method are proposed and validated using real flight data. In particular, the version dedicated to fin-stabilized projectiles allows the reconstruction of the trajectory where the measurement of some parameters is not available. Moreover, it shows that there is no need of any instrumentation at the beginning of the flight. The version of the identification method dedicated to the spin-stabilized projectiles allows the identification of aerodynamic coefficients which are varying during the flight. It shows that the aerodynamic coefficients of spin-stabilized projectile can be identified with accuracy without any onboard instrumentation
Rodrigues, Dominique. "Méthode de réciprocité : caractérisation de petits composants acoustiques, étalonnage des microphones en pression et en champ libre." Phd thesis, Université du Maine, 2008. http://tel.archives-ouvertes.fr/tel-00349206.
Повний текст джерелаCe propos met en cause la précision de l'étalonnage des étalons de mesure de pressions acoustiques et l'insuffisance des réglages d'appareils médicaux largement utilisés. Les enjeux pratiques, techniques et scientifiques ont donc leur importance et les études à mener comportent des exigences qui nécessitent des recherches approfondies. C'est ainsi que les thèmes abordés font appel ici à la méthode de la réciprocité en cavité et en champ libre.
Dans la première partie du travail, l'objectif recherché est d'adapter et d'améliorer la méthode de réciprocité en cavité. L'adaptation de cette méthode conduit à une technique de mesure d'impédances d'entrée de petits éléments acoustiques, tels que des tubes, fentes, cavités (utilisés dans l'oreille artificielle). L'amélioration des incertitudes de mesure des efficacités recherchée pour les hautes fréquences a conduit à proposer une modélisation améliorée d'un microphone ainsi que du dispositif d'étalonnage dans sa globalité de manière à étudier l'influence des modes radiaux dans la cavité sur les résultats de l'étalonnage.
La deuxième partie de ce travail trouve son origine dans une comparaison clé à l'échelle internationale portant sur les techniques d'étalonnage des microphones en champ libre. Cette comparaison clé a nécessité une refonte complète du dispositif expérimental du LNE, des techniques d'acquisitions et des méthodes de filtrage des perturbations liées aux faibles niveaux acoustiques mis en jeu. Ce travail a conduit à entreprendre des études plus approfondies sur les plans analytique et expérimental du concept de centre acoustique d'un microphone.
Certains résultats obtenus posent les bases des travaux futurs qui devraient permettre de poursuivre la modélisation pour réduire les incertitudes mais également pour prévoir la mise en oeuvre des méthodes adaptées à la métrologie des capteurs du futur qui seront fabriqués par des procédés relevant des microtechnologies.
Dettori, Lucia. "La méthode de Galerkin nonlinéaire en discrétisation par collocationL'équation de Cahn-Hilliard avec une énergie libre logarithmique." Paris 11, 1994. http://www.theses.fr/1994PA112034.
Повний текст джерелаDeloze, Thibaut. "Couplage fluide-solide appliqué à l’étude de mouvement d’une sphère libre dans un tube vertical." Strasbourg, 2011. http://www.theses.fr/2011STRA6033.
Повний текст джерелаThe thesis deals with the trajectory of a sphere falling in a tube filled with a Newtonian fluid at rest. This topic is motivated by the understanding of phenomena related to particle transport, including the interactions between the wake downstream of the particle and a wall nearby. The particle transport is widespread in many areas, such as the trajectory of the therapeutic particles in the lungs, the trajectory of the fuel particles and the trajectory of chemical reagents in fluidized beds. The simulations are made possible by the development of the chimera method (management of overlapped grids) implemented in a solver of the Navier-Stokes equation (NSMB software). The developed chimera method is fast, automatic and parallel and it is validated on several static and moving flow cases. This method is firstly applied on the sphere in uniform translation in a tube. The states are similar to the flow past a sphere in infinity area (without wall tube influence). Then the method is performed for the free falling sphere in a tube. Three kinds of trajectory appear in the studied range: a vertical fall along the axis tube, an helical trajectory (no vortex shedding downstream of the sphere) and an helical path with a unsteady radius (flow with vortex shedding)
Rabier, Sylvain. "Développement d'un modèle éléments finis pour la simulation d'écoulements à surface libre : application au soudage." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11005.
Повний текст джерелаThis work is focused on the development of a three-dimensional finite element model to study the heat transfer in the whole pieces to weld and the fluid flow in the weld pool resulting from the welding process. The numerical model allows us to consider the evolution of the free surface of the molten pool by the use of a moving mesh. The moving mesh is numerically implemented with an ALE Method. Validation of the model is conducted by the way of several tests problems with notably the numerical simulation of a free surface flow with an analytical solution. We have been interested more specifically to three of the main physical phenomena generating fluid flow in the molten pool. These are the driving effect due to the welding speed, the Marangoni effect and the welding process pressure. The numerical simulations, being performed separating the physical phenomena, have permitted to quantify the influence of the weld pool flow on the temperature distribution in the cases treated
Campagne, Gaëlle. "Simulation numérique directe de l'intéraction turbulence / surface libre pour l'analyse du transfert intercomposantes." Toulouse, INPT, 2006. http://ethesis.inp-toulouse.fr/archive/00000435/.
Повний текст джерелаA Direct Numerical Simulation of the interaction between no-shear turbulence and a free-slip surface is performed using a pseudo-spectral method. The originality of the configuration yields in the fact that the turbulence is created by a distant random forcing term localised in the vicinity of a plane parallel to the surface. The flow is therefore statistically steady and the surface layer is continuously fed by turbulent diffusion. The evolutions of the statistical quantities and of Reynolds shear stresses are studied and are used to define the structure of the interaction layer. A new method of analyzing and quantifying the elementary structures, that contribute to the intercomponent energy transfers, is proposed and evaluated. It allows some improvements in the understanding of the mechanisms linked to the influence on the pressure-deformation correlation, in the presence of an impermeable surface
Rebeyrotte, Alain. "Contribution à l'étude des effets non-linéaires sur la surface libre au-dessus de corps immergés en mouvement instationnaire." Poitiers, 2003. http://www.theses.fr/2003POIT2277.
Повний текст джерелаThe aim of this work is to study the nonlinear effects on unsteady flows above a submerged body, and particularly the shape of the free surface. The originality of our research is that we keep the two free surface conditions in their nonlinear formulation. We use a MEL procedure to solve the problem : at each time step we know the potential on the free surface and its position, we then solve a mixed boundary value problem to find the unknown strength of the Rankine singularities. To update the potential and the elevation of the free surface we use a 4th order Runge-Kutta scheme. In order to avoid singular kernel in the integral calculation we use a desingularized technique for the distribution of the singularities on the free surface. First we apply this method to a source-sink pair moving above the free surface to validate the discretisation and calculation procedures. Then we study the motion of a submerged ellipsoid in infinite and shallow water. The end of this work presents the simulation of a source sink-pair in circular motion and the study of the steady wave train generated by a sine-shaped obstacle on a flat bottom in a uniform stream
Berraki, Madjid. "Étude théorique et modélisation d'une source piézoélectrique enterrée unidirectionnelle pour applications sismiques." Lille 1, 2004. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2004/50376-2004-Berraki.pdf.
Повний текст джерелаL'évolution des enregistrements effectués au niveau des récepteurs n'est pas attribuable uniquement aux variations dans le réservoir. La solution proposée dans cette thèse est la conception une source enterrée unidirectionnelle. La première partie expose un principe de source unidirectionnelle. Il s'agit de la combinaison, en milieu infini et en champ lointain, de forces ponctuelles dont les amplitudes complexes sont ajustées. La seconde partie décrit le rayonnement de la source unidirectionnelle idéale en milieu réel. Le modèle développé repose sur la détermination de la fonction de Green du milieu semi-infini, soit par méthode de Cagniard De Hoop (demi-espace), soit par méthode Réflectivité/DWN (milieu semi-infini stratifié). Un transducteur piézoélectrique unidirectionnel enterré, est modélisé dans la troisième partie. Le code éléments finis ATILA est utilisé pour modéliser la source piézoélectrique. Le milieu extérieur est représenté par sa matrice d'impédance, calculée soit par méthode itérative (demi-espace), soit par le code éléments de frontière MISSAXI (milieu semi-infini stratifié)
Darbani, Mohsen. "Approche sans maillage basée sur la Méthode des Eléments Naturels (NEM), pour les écoulements bidimensionnels à surface libre." Compiègne, 2009. http://www.theses.fr/2009COMP1851.
Повний текст джерелаSolving equation with free surface often encounters numerical difficulties related to excessive mesh distortion as is the case of dambreak or breaking waves. In this work we explore the meshfree technique based on the Natural Element Method(NEM) to simulate the 2D fluid flow in presence of strong gradients. The equations considered here are those of Saint-Venant shallow water where we consider the full non-linear equations, with a transient flow under the Coriolis effect. The nonlinear terms are computed by using a Lagrangian technique based on the method of the characteristics. This will allow us to avoid setting up a numerical algorithm, like Newton-Raphson’s, which tend to extend the computing time. However, the management of boundary conditions remains a major difficulty in meshless methods. We have therefore defined a thin geometrical domain close to the boundaries and a domain for computing that will be submitted to nodal enrichment, when the particles leave the computational domain
Dupire, Laurent. "Étude d'un mutant embryogène d'Asparagus officinalis L. : description cytologique, approches biochimiques et moléculaires." Lille 1, 1999. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1999/50376-1999-233.pdf.
Повний текст джерелаMargarido, Milena. "Synthèse d’architectures logicielles pour systèmes-de-systèmes : une méthode automatisée par résolution de contraintes." Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS480/document.
Повний текст джерелаSystems-of-Systems (SoS) encompass diverse and independent systems that must cooperate with each other for performing a combined action that is greater than their individual capabilities. In parallel, architecture descriptions, which are the main artifact expressing software architectures, play an important role in fostering interoperability among constituents by facilitating the communication among stakeholders and supporting the inspection and analysis of the SoS from an early stage of its life cycle. The main problem addressed in this thesis is the lack of adequate architectural descriptions for SoS that are often built without an adequate care to their software architecture. Since constituent systems are, in general, not known at design-time due to the evolving nature of SoS, the architecture description must specify at design-time which coalitions among constituent systems are feasible at run-time. Moreover, as many SoS are being developed for safety-critical domains, additional measures must be placed to ensure the correctness and completeness of architecture descriptions. To address this problem, this doctoral project employs SoSADL, a formal language tailored for the description of SoS that enables one to express software architectures as dynamic associations between independent constituent systems whose interactions are mediated for accomplishing a combined action. To synthesize concrete architectures that adhere to one such description, this thesis develops a formal method, named Ark, that systematizes the steps for producing such artifacts. The method creates an intermediate formal model, named TASoS, which expresses the SoS architecture in terms of a constraint satisfaction problem that can be automatically analyzed for an initial set of properties. The feedback obtained in this analysis can be used for subsequent refinements or revisions of the architecture description. A software tool named SoSy was also developed to support the Ark method as it automates the generation of intermediate models and concrete architectures, thus concealing the use of constraint solvers during SoS design and development. The method and its accompanying tool were applied to model a SoS for urban river monitoring in which the feasibility of candidate abstract architectures is investigated. By formalizing and automating the required steps for SoS architectural synthesis, Ark contributes for adopting formal methods in the design of SoS architectures, which is a necessary step for obtaining higher reliability levels
Chirat, Guillaume. "Description et modélisation du comportement spatial et alimentaire de troupeaux bovins en libre pâture sur parcours, en zone tropicale sèche." Thesis, Montpellier, SupAgro, 2010. http://www.theses.fr/2010NSAM0005/document.
Повний текст джерелаArid and sub-arid areas, where are located most of the world's cattle, are concerned by a sustainable improvement of their productivity. During the dry season, that can last 9 months, herds range free on territories made of spontaneous plants and crop residues from cultivated areas. From observations of animal activities, intake rates and daily circuits on a sahelo-sudanian territory, we built a herd-oriented model which simulates spatial behavior (circuits) and feed intake (spatialized intake). Our approach consisted in introducing successively the very necessary information that realistically represents animal behaviors. The heuristic rules of herds'choices are a combination of our observations and ethological theories: i.e. factors linked to pastoral resources (cover types, biomass) and other abiotic factors (attraction to watering point and to night park) or to human decisions (breeder's practices). Integration of short-term intake process is based on relationships established between intake rate and available biomass of each cover type in order to emerge daily intakes. Altogether, the implemented equations are within the theoretical frame of the Functional response. The coupling of daily simulated circuits with prevision of intake, allowed calibration of agents Herds decision rules that fit observed behaviors. Although parsimonious, our approach kept the necessary representation of biological phenomena in order to ensure a model transportability to other semi-arid rangeland systems, if parameters are adjusted. Finally, this thesis proposes an original methodology to simulate spatialized feed uptakes by free-ranging cattle in the tropics, with ecological production improvement as a goal
Cornetti, Giovanni. "Étude d'une alternative aux équations de Saint-Venant par une méthode à frontière libre rapprochée par peu de couches." Paris 6, 1995. http://www.theses.fr/1995PA066572.
Повний текст джерелаOuisse, Xavier. "Détermination de modèles équivalents de rayonnement de structures complexes en champ libre et milieu semi-anéchoïque." Compiègne, 1996. http://www.theses.fr/1996COMPD977.
Повний текст джерелаHamroun, Boussad. "Approche hamiltonienne à ports pour la modélisation, la réduction et la commande des systèmes non linéaires à paramètres distribués : application aux écoulements à surface libre." Grenoble INPG, 2009. http://www.theses.fr/2009INPG0119.
Повний текст джерелаA port hamiltonian formulation for shallow water equations is given. It exhibits trivially some interesting properties like passivity and energy conservation. Using a geometric reduction scheme based on mixed finite elements methods, a reduced port hamiltonian model was derived. This reduction preserves the dynamical qualitative properties of the original model. We show that the reduced port Hamiltonian model exhibits interesting spectral and input-output properties which converge two those of infinite dimensional model. A control algorithm which allows regulating the flow and water level are designed using the IDA-PBC and energy shaping method. The energy shaping method was generalized to the infinite dimensional model. Simulation results and an experimental validation of the control algorithm on a micro-canal platform are presented showing the effectiveness of the control law
Decoene, Astrid. "Modèle hydrostatique pour les écoulements à surface libre tridimensionnels et chémas numériques." Paris 6, 2006. https://tel.archives-ouvertes.fr/tel-00180003.
Повний текст джерелаChouchaoui, Ahmed. "I) i) Description dynamique de systèmes quantiques par la méthode fonctionnelle et la méthode du potentiel effectif, ii) Résolution d'une classe de potentiels quasi-exactement solubles." Mulhouse, 1996. http://www.theses.fr/1995MULH0411.
Повний текст джерелаEssai, Azeddine. "Méthode hybride parallèle hétérogène et méthodes pondérées pour la résolution des systèmes linéaires." Lille 1, 1999. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1999/50376-1999-77.pdf.
Повний текст джерелаLu, Hai Yun. "Extension de la méthode des discontinuités de déplacement aux comportements mécaniques non linéaires." Lille 1, 1999. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1999/50376-1999-409.pdf.
Повний текст джерелаNguyen, Huu Ha. "Analyse de la surface libre dans un canal par une méthode optique : application à l'impact des vagues sur une structure." Le Havre, 2008. http://www.theses.fr/2008LEHA0004.
Повний текст джерелаThis PhD study aims to analyze the free surface within a wave channel by using a new optical measurement. This process uses a video and a laser induced fluorescence to visualize the water movement within a wave channel equipped with glass walls. The good contrast between the water and the air obtained on the captured images allows to detect accurately the free surface. A pixel range can give one punctual evolution of the free surface like a traditional punctual measurement of the free surface (for example: resistive probe). So the space resolution of the free surface can be obtained with a very high resolution. This optical measurement opens an in-depth investigation on the decomposition of incident and reflected harmonic waves using four wave gauges proposed by Lin et al. (2004). On the one side, it confirms the good pertinence of this method with the fundamental waves. On the other side, some difficulties appear about the estimation of higher harmonic waves. The same conclusions are found by comparing the four fixed gauges method of Lin et al. (2004) with the moving probes method of Brossard et al. (2000). This new measurement method allows to characterize the different behaviours of the free surface nearby a sloping marine structure according to the structure inclinations. For this purpose, various parameters associated with the extreme forms of the free surface are analyzed in relation to the structure inclination
Szalek, Aline. "Modélisation de formes complexes : proposition d'une méthode de raccordement par déformation de carreaux jointifs." Nancy 1, 1993. http://www.theses.fr/1993NAN10027.
Повний текст джерелаDeleu, Arnaud. "Méthologie de description fonctionnelle pour la synthèse des commandes des convertisseurs bidirectionnels : contrôle des commutations et algorithmes." Lille 1, 1997. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1997/50376-1997-83.pdf.
Повний текст джерелаFrançois, Nathalie. "Méthode d'application de la géométrie fractale à la description des systèmes de villes et des réseaux de transports." Paris 1, 1997. http://www.theses.fr/1997PA010581.
Повний текст джерелаCampagne, Gaelle. "Simulation numérique directe de l'interaction turbulence/surface libre pour l'analyse du transfert intercomposantes." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2006. http://tel.archives-ouvertes.fr/tel-00326401.
Повний текст джерелаMagnin, Vincent. "Contribution à l'étude et à l'optimisation de composants optoélectroniques." Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-327.PDF.
Повний текст джерелаRoland, Christophe. "Méthodes d'accélération de convergence en analyse numérique et en statistique." Lille 1, 2005. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2005/50376-2005-Roland.pdf.
Повний текст джерелаDeloze, Thibaut. "Couplage fluide-solide appliqué à l'étude de mouvement d'une sphère libre dans un tube vertical." Phd thesis, Université de Strasbourg, 2011. http://tel.archives-ouvertes.fr/tel-00687119.
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