Letteratura scientifica selezionata sul tema "Modèle Darcy"

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Articoli di riviste sul tema "Modèle Darcy"

1

Fabrie, Pierre. "Solutions fortes et majorations asymptotiques pour le modèle de Darcy Forchheimer en convection naturelle". Annales de la faculté des sciences de Toulouse Mathématiques 10, n. 1 (1989): 7–26. http://dx.doi.org/10.5802/afst.666.

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Daghari, H., e L. DeBacker. "Transfert d'eau dans un milieu poreux non isotherme". Revue des sciences de l'eau 13, n. 1 (12 aprile 2005): 75–84. http://dx.doi.org/10.7202/705382ar.

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Les transferts d'eau dans le sol sont généralement, pour des raisons de facilité, supposés se dérouler dans des conditions isothermes. Les modèles proposés couplant les transferts hydriques et thermiques se heurtent aux difficultés inhérentes à la détermination des coefficients de transfert. Disposant de l'évolution de la température, de la succion et de la teneur en eau dans les profils du sol de lysimètre, une comparaison portant sur l'importance des gradients hydriques et thermiques dans le transfert d'eau en phases liquide et vapeur a été menée. Il se dégage clairement, que dans le domaine de teneurs en eau qui intéressent l'agronome (teneur en eau supérieure à celle au point de flétrissement), l'essentiel des transferts se fait via la phase liquide. En effet, les flux dus aux gradients de teneur en eau dépassent d'au moins deux ordres de grandeur les flux induits par les gradients de température. Ce qui confirme bien la validité des équations de Darcy-Richards (DARCY, 1856; RICHARDS, 1931) où l'effet de température est négligé.
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Neto, Guilherme Luiz Oliveira, Nívea Gomes Nascimento de Oliveira, Francisco Alves Batista, Gustavo Henrique de Almeida Barbalho, Anderson Melchiades Vasconcelos da Silva, Lucas Pereira Castanheira Nascimento, Severino Rodrigues de Farias Neto e Antonio Gilson Barbosa de Lima. "Water-Oil Separation Process Using a Porous Ceramic Membrane Module: An Investigation by CFD". Defect and Diffusion Forum 407 (marzo 2021): 22–30. http://dx.doi.org/10.4028/www.scientific.net/ddf.407.22.

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Environmental concern has encouraged development related to polluted water treatment. Produced water originated from oil exploration has been submitted to different separation processes such as settling tanks, floaters, two-phase and three-phase separators, hydrocyclones, and membranes. On the use of membranes, the goal is to separate soluble components from solutions based on the size, charge, shape, and molecular interactions between the solute and membrane surface. In the present work, a numerical study was developed on the oil-water mixture separation process using a porous ceramic membrane module. The mathematical model used in this research is composed of mass and momentum conservation equations coupled to Darcy ́s law and SST k-ω turbulence model. Simulations were carried out employing the Ansys CFX commercial software. Results of the pressure, velocity, oil concentration distribution inside the device and membrane are presented and discussed. The results showed that the geometric aspects of the proposed microfiltration module and the membrane distribution within the separation module had a significant influence on the hydrodynamic flow leading to polarized layer dispersion.
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Doucet, J. P., A. Panaye, Shen Gang Yuan e J. E. Dubois. "Évolution des effets α-fonctionnels en RMN13C. application du modèle topologique darc-pulfo en série alicyclique". Journal de Chimie Physique 82 (1985): 607–11. http://dx.doi.org/10.1051/jcp/1985820607.

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Wan, Fa, e Zhong-Ming Jiang. "Seepage and Heat Transfer Characteristics of Gas Leakage under the Condition of CAES Air Reservoir Cracking". Geofluids 2021 (27 luglio 2021): 1–18. http://dx.doi.org/10.1155/2021/5182378.

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The contradiction between supply and demand of energy leads to more and more attention on the large-scale energy storage technology; Compressed Air Energy Storage (CAES) technology is a new energy storage technology that is widely concerned in the world. The research of coupled heat transfer and seepage in fractured surrounding rocks is the necessary basis to evaluate the operation safety and effectiveness of CAES. Current studies point to the possibility of cracking in concrete liner seals, but the thermodynamic processes and leakage characteristics of compressed air in the presence of cracking and the heat transfer characteristics of seepage have not been addressed and reported. In order to investigate the leakage, the gas seepage and heat transfer law in fractured rock when the hard rock CAES gas reservoir seal cracks, the COMSOL fracture Darcy module, and the non-Darcy Forchheimer model are used as the constitutive seepage. The global ODE is used to calculate the thermodynamic process of compressed air in gas storage with coupled seepage and heat transfer process. The pressure and temperature of compressed air are obtained as the unsteady boundary of the seepage heat transfer model. A program for calculating the seepage and heat transfer characteristics of fractured surrounding rock in the CAES gas reservoir is established. On this basis, with the proposed Suichang CAES cavern as the background, the seepage and heat transfer characteristics of the fractured surrounding rock of the gas storage are studied. The results showed that when there are fewer cracks in the lining and surrounding rock of the air reservoir, the air pressure decreases due to a small amount of air leakage after 30 operation cycles, and the leakage rate of each cycle is 0.7% of the gas storage capacity, but it still meets the engineering requirements. If the plant is operating under these conditions, the charging rate will need to be increased by 1.2 kg/s per cycle charging stage. In the discharging and power generation phase, the high-pressure air that previously percolated into the rock mass cracks could flow back into the air storage through the lining cracks. Therefore, it is incorrect and unreliable to consider the gas which flows out from the inner surface of the lining as unusable. When the lining crack width is less than 0.3 mm, the seepage flow is Darcy flow and the non-Darcy effect can be ignored; when the lining crack width is greater than 0.5 mm, the non-Darcy effect of seepage cannot be ignored. The gas velocity in the surrounding rock fracture medium is on the order of 0.01 m/s with an influence range of over 100 m, and the gas velocity in the pore medium is on the order of 10-6 m/s with an influence range of 50 m. The findings of this study contribute to a better understanding of the interaction between the thermodynamic properties of compressed air and the seepage heat transfer process in compressed air storage underground reservoirs, as well as the gas leakage process in the event of liner seal cracking.
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Walty, Ivete Lara Camargos. "Cópia ou ruptura: um movimento pendular". Cadernos de Linguística e Teoria da Literatura 13, n. 26 (7 aprile 2016): 107. http://dx.doi.org/10.17851/0101-3548.13.26.107-119.

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RESUMO: A crítica brasileira sempre se preocupou com a questão da autonomia das literaturas brasileira e latino-americana, dividindo-se, como a própria literatura, entre os pólos do modelo e da cópia, da continuidade e da ruptura. Este trabalho busca reler alguns textos-críticos, associando-os a obras literárias que têm como objeto o índio – Alencar, Darci Ribeiro e Vargas Llosa –, bem como às histórias contadas diretamente por um índio. Nesse percurso, busca-se refletir sobre o lado índio da literatura latino-americana em diálogo com suas outras facetas, explicitando a contradição inerente ao processo.RÉSUMÉ: La question de l'autonomie des littératures brésiliennes et latino-américaine a toujours préocupé la critique brésilienne, ce qui l'a fait se partager, tout comme la littérature elle-même, entre les faces du modèle et da la copie, entre celles de la continuité et de la rupture. Ce travail cherche à relire quelques textes critiques, en les faisant s'associer à des oeuvres littéraires dont 1'objet est constitué par 1'indien – Alencar, Darci Ribeiro et Vargas Llosa –, aussi bien qu'aux histoires racontées par un indien. On a tâché, chemin faisant, de réfléchir au côté indien de la littérature latino-américaine nous tournant vers le dialogue avec ses autres aspects, pour éclairer la contradiction inhérente au procès.
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Cancilla, Nunzio, Luigi Gurreri, Gaspare Marotta, Michele Ciofalo, Andrea Cipollina, Alessandro Tamburini e Giorgio Micale. "Performance Comparison of Alternative Hollow-Fiber Modules for Hemodialysis by Means of a CFD-Based Model". Membranes 12, n. 2 (20 gennaio 2022): 118. http://dx.doi.org/10.3390/membranes12020118.

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Commercial hemodialyzers are hollow-fiber cylindrical modules with dimensions and inlet–outlet configurations dictated mostly by practice. However, alternative configurations are possible, and one may ask how they would behave in terms of performance. In principle, it would be possible to depart from the standard counter-flow design, while still keeping high clearance values, thanks to the increase in the shell-side Sherwood number (Sh) due to the cross-flow. To elucidate these aspects, a previously developed computational model was used in which blood and dialysate are treated as flowing through two interpenetrating porous media. Measured Darcy permeabilities and mass transfer coefficients derived from theoretical arguments and CFD simulations conducted at unit-cell scale were used. Blood and dialysate were alternately simulated via an iterative strategy, while appropriate source terms accounted for water and solute exchanges. Several module configurations sharing the same membrane area, but differing in overall geometry and inlet–outlet arrangement, were simulated, including a commercial unit. Although the shell-side Sherwood number increased in almost all the alternative configurations (from 14 to 25 in the best case), none of them outperformed in terms of clearance the commercial one, approaching the latter (257 vs. 255 mL/min) only in the best case. These findings confirmed the effectiveness of the established commercial module design for the currently available membrane properties.
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Мукутадзе, Александр, e Aleksandr Mukutadze. "INVESTIGATION OF TRANSFER RATIO FOR DAMPFER WITH DOUBLE LAYER POROUS RING". Bulletin of Bryansk state technical university 2016, n. 3 (30 settembre 2016): 67–75. http://dx.doi.org/10.12737/22012.

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In the paper on the basis of Darcy equations defining a lubricant flow in porous layers and modified Reynolds equation is solved a problem of unsteady flow of viscous incompressible lubricant in the gap of a doublelayer porous damper. A case is considered when permeability in porous layers changes according to a normal low, and a combined feed of lubricant is carried out simultaneously in axial and radial directions. As a result of the solution of the problem specified there is found a field of pressures in porous layers and a lubrication layer, there are also obtained analytical dependences for efforts in an oil film, a module of unbalance transmitted force and also stationary and transitional transfer ratios are determined. It is proved that the combined lubricant feed a damper functions more stably, than at a separate axial and radial its feed. The obtained specified calculated models allowed determining the efficiency of additional factors account, and also carrying out a comparative analysis of results newly obtained and already available that defined a larger proximity of a new model to real practice.
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Мукутадзе, Александр, Aleksandr Mukutadze, Камил Ахвердиев, Kamil Akhverdiev, Борис Флек e Boris Flek. "DAMPER WITH POROUS ANISOTROPIC RING". Bulletin of Bryansk state technical university 2016, n. 3 (30 settembre 2016): 17–28. http://dx.doi.org/10.12737/22006.

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In the work on the basis of Darcy equations defining lubricant flow in porous layers, and of Reynolds modified equation the problem of an unsteady motion of viscous incompressible lubricant in the gap of a por-ous damper is under solution. A case is under consideration when a forced lubricant supply is carried out in circumferential and radial directions taking into account the influence of orthogonal anisotropy of a porous layer. As a result of the solution of the problem specified there is found a field of pressures in a porous and lubricating layer, and analytical dependences for efforts in an oil film are obtained. Besides, there is defined a module of an unbalance transmitted effort and also stationary and transient ratios of transfer. It is proved that at the forced lubricant feed in a circumferential or radial direction taking into account the influence of orthogonal anisotropy of a porous layer, a damper functions more steadily. The obtained specified calculated models al-lowed defining a number of supplementary factors and also carrying out a comparative analysis of results newly obtained and already existing ones. It confirmed a larger proximity of a new model an actual practice.
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Knepper, Marie Isabell, e Jens Dernedde. "Zona Pellucida like Domain Protein 1 (ZPLD1) Polymerization Is Regulated by Two Distinguished Hydrophobic Motifs". International Journal of Molecular Sciences 23, n. 22 (11 novembre 2022): 13894. http://dx.doi.org/10.3390/ijms232213894.

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Zona Pellucida Like Domain 1 Protein (ZPLD1) is a main component of the cupula, a gelatinous structure located in the labyrinth organ of the inner ear and involved in vestibular function. The N-glycosylated protein is likely able to organize high-molecular-weight polymers via its zona pellucida (ZP) module, which is common for many extracellular proteins that self-assemble into matrices. In this work, we confirmed that ZPLD1 can form multimers while setting up a cellular model leveraging Madin–Darby canine kidney (MDCK) cells to study protein polymerization. We identified two motifs within ZPLD1 which regulate its polymerization and follow previously published conserved regions, identified across ZP proteins. Mutational depletion of either one of these modules led to diminished or abnormal polymer formation outside of the cells, likely due to altered processing at the plasma membrane. Further, intracellular polymer formation was observed. Proteolytic cleavage during secretion, separating the regulatory motif located distinct of the ZP module from the mature monomer, seems to be necessary to enable polymerization. While the molecular interactions of the identified motifs remain to be proven, our findings suggest that ZPLD1 is a polymer forming ZP protein following an orchestrated mechanism of protein polymerization to finally build up a gelatinous hydrogel.
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Tesi sul tema "Modèle Darcy"

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Nasser, El Dine Houssein. "Étude mathématique et numérique pour le modèle Darcy-Brinkman pour les écoulements diphasiques en milieu poreux". Thesis, Ecole centrale de Nantes, 2017. http://www.theses.fr/2017ECDN0022.

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Le système modélisant un écoulement de deux phases incompressibles dans un gisement pétrolier à large porosité est régi par la loi de Darcy-Brinkman. La vitesse de filtration de Darcy conduit à une équation elliptique en pression et une équation parabolique dégénérée en saturation. Ce système est très largement utilisé en milieu poreux. Dans cette thèse, on s’intéresse à la modification de Brinkman qui consiste à modifier la loi de Darcy en ajoutant un terme de dissipation en vitesse. Ce système conduit à une équation elliptique en pression et une équation parabolique non standard en saturation, régularisante en temps. On s’intéresse dans un premier temps à l’étude mathématique du système Darcy-Brinkman et à la régularité des solutions. Afin de simuler numériquement les solutions de ce problème, on propose une première étude de convergence d’un schéma aux volumes finis sur un maillage admissible et pour un milieu poreux homogène. Ensuite, une méthode combinée de type volumes finis-éléments finis non conformes est proposée pour tenir compte de l’anisotropie du milieu. Le but du deuxième volet de cette thèse est de tenir compte de la compressibilité des fluides. On propose de décrire le modèle de Darcy-Brinkman dans le cas monophasique compressible. On montre que ce modèle est bien posé en dimension un d’espace et sur l’espace entier. Ensuite, sous l’hypothèse de Bear, on montre également que le modèle est bien posé en dimension d ≥ 2
The system modeling a two incompressible phase flow with high porosity in an oil-field is governed by the law of Darcy-Brinkman. The velocity of filtration of Darcy leads to an elliptic equation in pressure and a degenerate parabolic equation in saturation. This system is widely used in porous media. In this thesis, we are interested in the modification of Brinkman which consists in modifying Darcy’s law by adding a viscosity disspative term. This system leads to an elliptic equation in pressure and unstandard parabolic equation in saturation regularized in time. First, we are interested in the mathematical study of the Darcy-Brinkman’s system and in the regularity of the solutions. To simulate numerically the solutions of this problem, we study the convergence of a finite-volume scheme on an admissible mesh for a homogeneous porous media. Then, we propose a combined method of finite volume - nonconforming finite element type to deal with the anisotropic of the media. In the second part of this thesis we deal with the compressibility of the fluids. We suggest a model of Darcy- Brinkman to describe the compressible monophasic case. We show that this model is well posed in dimension one in the whole space. Then, under the hypothesis of Bear, we also show that this model is well posed in dimension d ≥ 2
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Gassara, Dorra. "Simulation de la formation d'un dépôt de particules en microfiltration : effets des conditions hydrodynamiques et des interactions physicochimiques sur la morphologie et la perméabilité apparente du dépôt". Toulouse, INPT, 2007. http://ethesis.inp-toulouse.fr/archive/00000609/.

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La formation d'un dépôt de particules à la surface du filtre constitute un des phénomènes limitants de toutes les opérations de microfiltration. Au fur et à mesure de sa croissance, ce dépôt, qui ajoute une résistance supplémentaire à l'écoulement de fluide réduit progressivement le rendement énergétique du système filtrant. Ce travail a pour but de caractériser l'influence des conditions hydrodynamiques et physio-chimiques sur la morphologie et les propriétés de transport du dépôt. Notre étude est réalisée sur un domaine constitué d'un ou de plusieurs éléments unitaires représentatifs d'une surface filtrante modèle, muni des conditions aux limites périodiques. De plus, dans une approche quasi bidimensionnelle, le domaine est restreint à une cellule Hele-shaw dont l'épaisseur est égale au diamètre d'une particule, de telle sorte que le modèle de Darcy s'applique sur la totalité du domaine. Les particules sont injectées une par une à partir d'ue position initiale aléatoirement choisie et décrivent des trajectoires qui tiennent compte de la structure de l'écoulement et ses interactions physico-chimiques de type DLVO avec la surface poreuse et avec les particules déjà déposées. L'écoulement est recalculé une fois la particule déposée
The formation of particles cake on the surface of the filter constitues one of the limiting phenomena of all the microfiltration operations. Progressively with its growth, this deposit, which adds an additional resitance to the fluid flow, reduced gradually the energetic efficiency of the filter system. The purpose of this work, is to characterize the influence of the hydrodynamic and physicochemical conditions on the morphology and the transport properties of the cake. Our study is carried out on a field made up of one or more unit elements representative of a filter surface models, provided with boundary periodic conditions. Moreover, in a first approaches quasi two-dimensional, the field is restricts with a Hele-shaw cell of which the thickness is equal to the particle diameter, so that the model of Darcy applies to the totality of the field. The particles are injected one by one starting from an initial position by chance selected and describe trajectories which take account of the structure of the flow and the physicochemical interactions of type DLVO with porous surface and the particles already deposited. The flow of Darcy is recomputed once the particle deposited
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Grall, Véronique. "Étude expérimentale d'écoulements diphasiques liquide-gaz en mini-canaux et en milieu poreux modèle". Toulouse, INPT, 2001. http://www.theses.fr/2001INPT033H.

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Nous nous intéressons dans le cadre de ce travail à des écoulements diphasiques gaz-liquide co-courants ascendants en milieu poreux grossier (taille des pores supérieure au millimètre). Les situations considérées se distinguent des situations classiques par des effets capillaires qui ne sont plus dominants à l'échelle du volume élémentaire représentatif, par des effets d'inertie pouvant être importants et par une instationnarité marquée de l'interface liquide-gaz. Les écoulements sont étudiés expérimentalement dans deux structures modèles : des mini-canaux à section rectangulaire sans et avec constrictions, et un réseau bidimensionnel de cylindres spatialement périodique. Un premier volet est consacré aux écoulements fortement inertiels. Les différents régimes observés sont caractérisés, les pertes de charges et les saturations sont mesurées en fonction des vitesses superficielles de chaque phase. Ces données sont ensuite utilisées pour évaluer différents modèles proposés dans la littérature et basés sur des extensions empiriques de la loi de Darcy-Forchheimer. Cette évaluation met en évidence les limitations de ces modèles. Ceci conduit à proposer, pour le cas des mini-canaux, une nouvelle modélisation, plus physique, s'inspirant des méthodes développées pour les écoulements diphasiques en conduite. Cette approche fait cependant appel à un paramètre d'ajustement qui semble dépendre du caractère plus ou moins marqué des instationnarités interfaciales. La complexité générale des écoulements étudiés dans ce premier volet nous incite à revenir à une situation plus simple dans une double perspective de compréhension fine et de simulation numérique directe. Cette situation fait l'objet du second volet de la thèse. Nous y étudions l'ascension de trains de bulles sous l'action de la gravité dans un liquide au repos saturant le milieu modèle constitué par le réseau de cylindres spatialement périodique. Les trajectoires, vitesses d'ascension, déformations de bulles et conditions d'appariement sont étudiées expérimentalement pour la gamme des débits d'injection modérés. Aux plus forts débits, des situations complexes caractérisées par des appariements multiples, des coalescences et des ruptures d'amas conduisant à la formation d'un cône de dispersion sont observées.
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Fahs, Amin. "Modeling of naturel convection in porous media : development of semi-analytical and spectral numerical solutions of heat transfer problem in special domains". Thesis, Strasbourg, 2021. https://publication-theses.unistra.fr/restreint/theses_doctorat/2021/Fahs_Amin_2021_ED269.pdf.

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Le problème de la cavité poreuse carrée est largement utilisé comme cas de référence courant pour les problèmes de Convection Naturelle (CN) en milieux poreux. Il peut être utilisé pour plusieurs applications numériques, théoriques et pratiques. Par ailleurs, toutes les solutions de haute précision existantes dans la littérature scientifique sont développées dans des conditions de régime permanent. Cependant, il est bien connu que les processus de CN dans les milieux poreux se produisent naturellement dans un régime dépendant du temps, car les conditions aux limites peuvent être variables dans le temps. Pour surmonter cette difficulté, la solution en régime permanent est souvent simulée comme une solution transitoire qui évolue jusqu'à atteindre l'état d'équilibre. Ces régimes dépendant du temps sont très efficaces pour détecter les effets des variations de paramètres sur le processus physique de CN, en particulier pour les sujets d'intérêt de cette thèse: la variation du niveau d'inclinaison du domaine et la prise en compte des variations de température de la paroi chaude dans le temps. À cet effet, trois objectifs sont identifiés dans cette thèse: 1. Développer une solution de convection naturelle en fonction du temps dans des milieux poreux en utilisant le Modèle Darcy en deux modes: transitoire et instable. 2. Étudier le comportement en fonction du temps de la convection naturelle dans des milieux poreux ayant le niveau d'inclinaison du domaine comme paramètre variable dans deux modes: transitoire et instable. 3. Développer une solution de convection naturelle en fonction du temps dans des milieux poreux en utilisant le Modèle Darcy-Lapwood-Brinkman en deux modes: transitoire et instable. Pour ce faire, du fait de la grande précision dans les domaines simplement connectés, une méthode spectrale de résidus pondérés de type Galerkin est choisie pour développer une solution au problème de CN dans une cavité carrée poreuse. L’application de la procédure de Fourier-Galerkin (FG), deux configurations traitant des régimes instables sont considérées où chaque solution est dérivée pour une large gamme des nombres de Rayleigh (Ra) avec d'autres conditions spéciales. Ce travail de thèse est subdivisé en cinq chapitres. Dans le premier chapitre, nous avons présenté un aperçu physique du processus de convection naturelle en milieux poreux. Dans le deuxième chapitre, le développement mathématique des équations, la méthode de résolution et la procédure de résolution sont décrits en détails. Dans le chapitre trois, la première étude de cas de cette thèse, la solution dépendante du temps de la convection naturelle dans une cavité carrée remplie de milieux poreux saturé utilisant le modèle de Darcy est développé. Dans le chapitre quatre, le problème de variation temporelle de Darcy-Lapwood- Brinkman de CN dans une enceinte poreuse saturée carrée est étudié. Dans le chapitre cinq, les solutions dépendant du temps sont développées pour le problème de convection naturelle utilisant la loi de Darcy dans une cavité poreuse inclinée et considéré comme une étude complète sur les effets de l'inclinaison du domaine sur le processus physique du problème de convection libre. Pour tous les cas, les régimes transitoires et instables sont considérés
The problem of the porous square cavity is extensively used as a common benchmark case for Natural convection (NC) problem in porous media. It can be used for several numerical, theoretical, and practical purposes. All the existing high accurate solutions are developed under steady-state conditions. However, it is well known that the processes of NC in porous media occurs naturally in a time-dependent procedure, as boundary conditions can be variable in time. Also, the convergence of the steady-state solution is known to be difficult. To overcome this difficulty, the steady-state solution is often simulated as a transient solution that evolves until reaching the steady-state condition. These time-dependent modes are very efficient to detect the effects of the parameter variations on the physical process of NC, especially for the subject of interest in this thesis: the domain inclination level and hot wall temperature variation in time. For this purpose, three goals are identified in this Thesis: 1. Developing a time-dependent solution of natural convection in porous media using the Darcy model in two modes: Transient and unsteady. 2. Investigating the time-dependent behavior of natural convection in porous media having the domain inclination level as a variable parameter in two modes: Transient and unsteady. 3. Developing a time-dependent solution of natural convection in porous media using the Darcy-Lapwood-Brinkman model in two modes: Transient and unsteady. To do so, according to the high accuracy in the simply connected domains, one of the Galerkin spectral weighted residual method is chosen to develop a space-time dependent solution for NC problem in a square porous cavity. Applying the Fourier-Galerkin (FG) procedure, two configurations dealing with transient and unsteady regimes are considered where each solution is derived for a wide range of Rayleigh numbers with other special conditions. This work of thesis is explained in details as five chapters.The NC physical process with the time-dependent variations is described in the transient mode to reach the steady-state solution and for the unsteady mode during a one period using periodic sinusoidal boundary conditions on the cavity hot wall. Finally, the work of this thesis is described in details in five chapters; while the sixth and last chapter is devoted to the summary and conclusion.The results in this thesis work provide a set of high-accurate data that are published in three papers to be used for testing numerical codes of heat transfer in time-dependent configurations
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Peyrard, Dimitri. "Un modèle hydrobiogéochimique pour décrire les échanges entre l'eau de surface et la zone hyporhéique de grandes plaines alluviales". Toulouse 3, 2008. http://thesesups.ups-tlse.fr/549/.

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La zone hyporhéique est un bioréacteur pouvant influencer le fonctionnement biogéochimique des hydrosystèmes fluviaux. La quantification de son rôle vis-à-vis des flux d'eau et d'éléments dissous transitant dans l'hydrosystème de grande plaine alluviale a été réalisée par modélisation numérique. Le travail de modélisation s'appuie sur des données précédemment acquises sur les sites expérimentaux de Freienbrink (Allemagne), de l'Hers et de la Garonne (France). La démarche de modélisation a consisté à développer un modèle hydrodynamique couplant les équations de Saint Venant (2D) pour les écoulements de surface et les équations de Darcy-Dupuit pour le milieu poreux, ainsi qu'un modèle de transport réactif des formes dissoutes de l'azote minéral et de la matière organique. L'ensemble des conclusions souligne l'importance des échanges transitoires entre cours d'eau et zone hyporhéique qui favorisent le stockage de l'eau et l'activation des processus de dénitrification
The hyporheic zone is a bioreactor which can influence the biogeochemical functioning of fluvial hydrosystems. In this work, quantification of its role on water and solutes fluxes in hydrosystem of large alluvial floodplains was made by modelling approach. The proposed model was applied and validated using data previously measured on experimental sites of Freienbrink (Germany), Hers and Garonne (France). The complete model consists of two additional components: a hydrodynamic component (horizontal 2D Saint Venant equations for river flow and 2D Dupuit equations for hyporheic zone flow) coupled with a reactive solute-transport component for dissolved forms of mineral nitrogen and organic matter. The conclusions highlight the importance of transient exchanges between stream and hyporheic zone which facilitate water storage and denitrification processes activation
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Georgin, Eric. "Étude de l'effet piston au sein d'un fluide supercritique en milieux poreux". Bordeaux 1, 2007. http://www.theses.fr/2007BOR13407.

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Ce travail de thèse vise à étudier les mécanismes de transfert de masse et de chaleur au sein d'un fluide pur, au voisinage de son point critique, lorsque celui-ci sature une matrice poreuse. Hors milieu poreux, l'étude hydrodynamique et thermique des fluides supercritiques en absence de gravité et maintenu à volume constant, a mis en évidence une "accélération critique" du transport de chaleur par effet piston. Cet effet a pour conséquence une thermalisation très rapide et homogène du volume de fluide. L'impact d'un milieu poreux homogène et indéformable sur le devenir de l'effet piston est l'objet de ce travail. Une partie simulation numérique porte sur la vérificationd'un modèle théorique proposé pour décrire les régimes de propagation de la chaleur. Une patrie expérimentale présente, quant à elle, la réalisation d'une cellule instrumentée correspondant à la situation d'étude et des mesures tests réalisées au sein de celle-ci.
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Razi, Yazdan Pedram. "Contribution à l'étude de l'action des vibrations sur les écoulements de convection thermique ou solutale en présence ou en l'absence de gravité". Toulouse 3, 2004. http://www.theses.fr/2004TOU30234.

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Ce mémoire porte sur l’étude analytique et numérique de l’action des vibrations sur les écoulements de convection thermique et solutale en présence ou en l’absence de gravité. Les écoulements convectifs induits par un gradient de température, en présence des champs de gravité et/ou de vibration, sont étudiés dans le cadre de l’approximation de Boussinesq. Dans la première partie de cette thèse , on a étudié la stabilité linéaire et faiblement non linéaire du problème dit d’ Horton-Rogers-Lapwood sous l’effet des vibrations verticales parallèles au gradient thermique. On a utilisé deux approches différentes (méthode de moyennisation et méthode directe) pour analyser la stabilité linéaire du problème. A partir d’une analyse d’échelle effectuée sur les coefficients de l’équation de Mathieu, on a établi les critères permettant de comparer les résultats obtenus par ces deux approches. Dans la deuxième partie de ce mémoire, nous avons étudié l’influence des vibrations de hautes fréquences et de faibles amplitudes sur la naissance de la convection dans le cas d’un mélange binaire en présence d’effet Soret. Une étude de stabilité linéaire pour une cellule horizontale d’extension infinie remplie d’un mélange binaire est effectuée. Le formalisme des équations moyennées a été utilisé. La stabilité de la solution de quasi-équilibre, quelle que soit la direction des vibrations, est ensuite examinée dans le cas des faibles nombres d’onde en présence ou en l’absence de gravité. Nous avons obtenu pour cette configuration une relation analytique donnant les paramètres critiques. .
In the present work, we study the effect of the action of mechanical vibration on the convective motion in mono and multi-component fluids in the presence or in the absence of gravity. In the framework of the Boussineq approximation, the induced convective motion due to the temperature field in the presence of gravitational and vibrational fields are studied. In the first part of this work, the linear and weakly non-linear stability analysis of Horton-Rogers-Lapwood problem under the effect vertical vibration (parallel to the temperature gradient) has been carried out. Two different approaches (time-averaged and direct methods) are used to study the thermal stability analysis of this problem. By applying the results obtained from the scale analysis method to the coefficients of the Mathieu equation, the criteria for comparing the results from these two stability analysis approaches are found. In the second part of this work, the influence of directions of vibration of high frequency and small amplitude on the onset of Soret driven convection is addressed. The linear stability analysis in an infinite horizontal layer filled by a binary mixture is performed. The stability of quasi-equilibrium solution for an arbitrary direction of vibration in the presence or in the absence of gravity for long wave mode is then examined. For this case, an analytical relation giving the critical parameter is found. .
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Chevalier, Thibaud. "Écoulements de fluides à seuil en milieux confinés". Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00903850.

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Afin de mieux comprendre les spécificités de l'écoulement des fluides en seuil en géométries confinées, nous avons opté pour une approche multi-échelle expérimentale et/ou numérique dans des milieux poreux complexes et modèles. Nous montrons qu'il est possible d'utiliser la RMN pour visualiser des écoulements de fluides à seuil en géométrie complexe. Dans un milieu poreux, il est également possible de mesurer la distribution statistique des vitesses, ceci sans problème de résolution spatiale, grâce à la méthodologie de réglage d'une expérience d'injection sous IRM que nous avons mise en place. A l'aide de ces techniques, nous montrons que l'écoulement d'un fluide à seuil dans un pore modèle (une expansion-contraction axisymétrique) se localise dans la partie centrale du pore, dans le prolongement du tube d'entrée, tandis que les régions extérieures restent dans le régime solide. Des simulations numériques confirment ces résultats et montrent que la localisation de l'écoulement provient du confinement engendré par la géométrie. A l'inverse, nous montrons que pour un fluide à seuil s'écoulant dans un milieu poreux réel (en trois dimensions), il n'existe pas de zones au repos. De plus, la distribution de vitesse est identique à celle d'un fluide newtonien. Une analyse de ces résultats nous permet de prédire la forme de la loi de Darcy pour les fluides à seuil et de comprendre l'origine physique des paramètres déterminés par des expériences d'injection " macroscopiques "
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Pegaz-fiornet, Sylvie. "Etude de modèles pour la migration des hydrocarbures dans les simulateurs de bassin". Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10049.

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La modélisation de la migration des hydrocarbures dans les bassins sédimentaires a pour but d'évaluer leur potentiel pétrolier, en localisant et en quantifiant les accumulations d'hydrocarbures au sein des formations géologiques. Dans cette thèse, nous étudions les modèles de migration de type "Darcy" ainsi que des modèles simplifiés de types "ray-tracing" et "invasion percolation"; l'objectif est de mener une analyse critique et de proposer des améliorations tout en fournissant un guide pour une utilisation pertinente sur des cas d'étude.Tout d'abord, nous faisons une revue des mécanismes de la migration depuis l'échelle des pores jusqu'à l'échelle des bassins, puis nous présentons chacun des modèles.Dans le volet suivant, nous proposons deux algorithmes d'invasion percolation : le premier, adapté aux maillages structurés; le second, permettant de mieux prendre en compte les maillages non structurés. Dans un troisième volet, nous nous intéressons à la comparaison entre ces modèles, en nous concentrant sur ceux de types "Darcy" et "invasion percolation". Nous nous focalisons en premier lieu sur les aspects numériques en nous appuyant sur plusieurs cas tests; puis nous effectuons une comparaison formelle en étudiant la limite asymptotique de la solution du modèle de type "Darcy" en temps long. Nous présentons ensuite une série d'applications dont notamment l'étude d'un cas réel 3D en géométrie complexe.Finalement, nous concluons ce travail avec deux articles. Le premier montre une évolution des modèles de type "Darcy" en utilisant la méthode du raffinement local de maillage, avec une illustration sur un cas d'étude du nord du Koweït. Le deuxième synthétise les principaux résultats obtenus concernant les méthodes de "Darcy" et "d'invasion percolation"
Hydrocarbon migration modeling in sedimentary basins aims to localize and to quantify hydrocarbon accumulations in geological formations in order to estimate their petroleum potential. In this thesis, we study “Darcy” migration models and also simplified migration models such as “ray-tracing” and “invasion percolation”; the purpose is to conduct a critical analysis and to offer improvements while providing a guide for a relevant use on case studies.We start by a review of migration mechanisms from the pore scale to the basin scale, then we present each model.In a following part, we propose two invasion percolation algorithms: the first one is suited to structured grids, the second one allows to take better account of unstructured grids.In a third part, we take an interest in the comparison between the different models and particularly between “Darcy” and “invasion percolation” approaches. First we devote our attention to numerical aspects supported by several use cases; then we realize a formal comparison by studying the asymptotic limit of the “Darcy” model large time solution. Afterwards, we present several applications including the study of a 3D real case in complex geometry.Finally, we conclude this work with two articles. The first one shows an evolution of “Darcy” models by using the method of local grid refinement with an illustration on a case study from northern Kuwait. The second one synthesizes the main results on “Darcy” and “invasion percolation” methods
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Hyde, Eoin Ronan. "Multi-scale parameterisation of static and dynamic continuum porous perfusion models using discrete anatomical data". Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:4c7df64f-b134-4b5c-8502-e34fb2c937c9.

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The aim of this thesis is to replace the intractable problem of using discrete flow models within large vascular networks with a suitably parameterised and tractable continuum perfusion model. Through this work, we directly address the hypothesis that discrete vascular data can be incorporated within continuum perfusion models via spatially-averaged parameterisation techniques. Chapter 1 reviews biological perfusion from both clinical and computational modelling perspectives, with a particular focus on myocardial perfusion. In Chapter 2, a synthetic 3D vascular network was constructed, which was controllable in terms of its size and properties. A multi-compartment static Darcy perfusion model of this discrete system was parameterised via a number of techniques. Permeabilities were derived using: (i) porosity-scaled isotropic (ϕI); (ii) Huyghe and Van Campen (HvC); and (iii) projected-PCA parameterisation methods. It was found that HvC permeabilities and pressure-coupling fields derived from the discrete data produced the best comparison to the spatially-averaged Poiseuille pressure. In Chapter 3, the construction and analysis of high-resolution anatomical arterial vascular models was undertaken. In Chapter 4, various anatomically-derived vascular networks were used to parameterise our perfusion model, including a microCT-derived rat capillary network, a single arterial subtree, and canine and porcine whole-organ arterial models. Allowing for general-connectivity (as opposed to strictly-hierarchical connectivity) yielded a significant improvement on the continuum model pressure. For the whole-organ model however, it was found that the best results were obtained by using porosity-scaled isotropic permeabilities and anatomically-derived pressure-coupling fields. It was also discovered that naturally occurring small length but relatively large radius vessels were not suitable for the HvC method. In Chapter 5, the suitability of derived parameters for use within a dynamic perfusion model was examined. It was found that the parameters derived from the original static network were adequate for application throughout the cardiac cycle. Chapter 6 presents a concluding discussion, highlighting limitations and future directions to be investigated.
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Libri sul tema "Modèle Darcy"

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Dudgeon, C. R. Non-Darcy flow of groundwater. Manly Vale, N.S.W: University of New South Wales, Water Research Laboratory, 1985.

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Capitoli di libri sul tema "Modèle Darcy"

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Nazarenko, Nelli N., e Anna G. Knyazeva. "Transfer of a Biological Fluid Through a Porous Wall of a Capillary". In Springer Tracts in Mechanical Engineering, 503–20. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-60124-9_22.

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AbstractThe treatise proposes a model of biological fluid transfer in a dedicated macropore with microporous walls. The distribution of concentrations and velocity studies in the capillary wall for two flow regimes—convective and diffusive. The largest impact on the redistribution of concentration between the capillary volume and its porous wall is made by Darcy number and correlation of diffusion coefficients and concentration expansion. The velocity in the interface vicinity increases with rising pressure in the capillary volume or under decreasing porosity or without consideration of the concentration expansion.
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Chwe, Michael Suk-Young. "Austen’s Competing Models". In Jane Austen, Game Theorist. Princeton University Press, 2014. http://dx.doi.org/10.23943/princeton/9780691162447.003.0007.

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This chapter examines Jane Austen's competing models of human behavior that also offers important insights into strategic thinking. One competing model focuses on people's emotions, which Austen acknowledges can cause bad decisions. For example, the jealous Caroline Bingley remarks to Mr. Darcy that Elizabeth's eyes have “a sharp, shrewish look,” but this only makes him reply that Elizabeth is “one of the handsomest women of my acquaintance.” Influenced by emotion, Miss Bingley does not think her plan through and it backfires. Emotions can affect people's choices, but people can strategically manage their emotions as well. The chapter proceeds by discussing Austen's other competing models dealing with instincts, habits, rules or principles, ideology, intoxication, constraints, and social factors like envy and decorum.
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Filipovic, Nenad, Milos Radovic, Dalibor D. Nikolic, Igor Saveljic, Zarko Milosevic, Themis P. Exarchos, Gualtiero Pelosi, Dimitrios I. Fotiadis e Oberdan Parodi. "Computer Predictive Model for Plaque Formation and Progression in the Artery". In Coronary and Cardiothoracic Critical Care, 220–45. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8185-7.ch012.

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In this chapter we described predictive model for plaque formation and progression in the coronary and carotid artery. A full three-dimensional model for plaque formation and progression, coupled with blood flow and LDL concentration is analysed. The Navier-Stokes equations together with the Darcy law for model blood filtration and Kedem-Katchalsky equations are implemented. Additionally, the system of three additional reaction-diffusion equations for simulation of the inflammatory process is coupled with full incremental iterative procedure. We developed hybrid genetic algorithm for fitting parameters of ODE model for oxidized LDL, macrophage, smooth muscle cell and foam cell concentration evolution in time. The animal carotid and coronary artery after 2 month of high fat diet are examined. We compared with CT our computer model of the plaque size for three groups of patients: De-novo, Old-lesions and Control patients. Detailed shear stress distributions for baseline and follow-up for these patients are given. There is a good matching for plaque size and location.
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Filipovic, Nenad, Milos Radovic, Dalibor D. Nikolic, Igor Saveljic, Zarko Milosevic, Themis P. Exarchos, Gualtiero Pelosi, Dimitrios I. Fotiadis e Oberdan Parodi. "Computer Predictive Model for Plaque Formation and Progression in the Artery". In Handbook of Research on Trends in the Diagnosis and Treatment of Chronic Conditions, 279–300. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-4666-8828-5.ch013.

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In this chapter we described predictive model for plaque formation and progression in the coronary and carotid artery. A full three-dimensional model for plaque formation and progression, coupled with blood flow and LDL concentration is analysed. The Navier-Stokes equations together with the Darcy law for model blood filtration and Kedem-Katchalsky equations are implemented. Additionally, the system of three additional reaction-diffusion equations for simulation of the inflammatory process is coupled with full incremental iterative procedure. We developed hybrid genetic algorithm for fitting parameters of ODE model for oxidized LDL, macrophage, smooth muscle cell and foam cell concentration evolution in time. The animal carotid and coronary artery after 2 month of high fat diet are examined. We compared with CT our computer model of the plaque size for three groups of patients: De-novo, Old-lesions and Control patients. Detailed shear stress distributions for baseline and follow-up for these patients are given. There is a good matching for plaque size and location.
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Marzougui, Souad, e Mourad Magherbi. "Irreversibility and Heat Transfer in Darcy-Forchheimer Magnetized Flow in a Porous Double Lid-Driven Cavity Filled With Copper-Water Nanofluid". In Advances in the Modelling of Thermodynamic Systems, 134–53. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8801-7.ch008.

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The present work reports a numerical simulation of entropy generation and heat transfer in a lid-driven porous cavity filled with a nanofluid using Darcy-Forchheimer model. Given the large number of dimensionless parameters related to this problem, some of them are kept constant and therefore the other governing dimensionless number such as number, the Hartman number, and the nanoparticles volume fraction, 0£Ha£50, 2%£φ£8%, respectively. The effects of the nanoparticles volume fraction and Hartman number on the different irreversibilities are studied. Results show that the entropy generation is strongly affected by the increase of Hartmann number and the volume fraction. Results reveal that the irreversibility in the nanofluid decrease with the nanoparticle volume fraction for different Hartmann numbers.
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Gasaluck, W. "Analysis of non-Darcy flow in unsaturated soils modeled by finite element method". In Unsaturated Soils for Asia, 171–75. CRC Press, 2020. http://dx.doi.org/10.1201/9781003078616-26.

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Gray, William G., e Michael A. Celia. "Incorporation of Interfacial Areas in Models of Two-Phase Flow". In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0006.

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The mathematical study of flow in porous media is typically based on the 1856 empirical result of Henri Darcy. This result, known as Darcy’s law, states that the velocity of a single-phase flow through a porous medium is proportional to the hydraulic gradient. The publication of Darcy’s work has been referred to as “the birth of groundwater hydrology as a quantitative science” (Freeze and Cherry, 1979). Although Darcy’s original equation was found to be valid for slow, steady, one-dimensional, single-phase flow through a homogeneous and isotropic sand, it has been applied in the succeeding 140 years to complex transient flows that involve multiple phases in heterogeneous media. To attain this generality, a modification has been made to the original formula, such that the constant of proportionality between flow and hydraulic gradient is allowed to be a spatially varying function of the system properties. The extended version of Darcy’s law is expressed in the following form: qα=-Kα . Jα (2.1) where qα is the volumetric flow rate per unit area vector of the α-phase fluid, Kα is the hydraulic conductivity tensor of the α-phase and is a function of the viscosity and saturation of the α-phase and of the solid matrix, and Jα is the vector hydraulic gradient that drives the flow. The quantities Jα and Kα account for pressure and gravitational effects as well as the interactions that occur between adjacent phases. Although this generalization is occasionally criticized for its shortcomings, equation (2.1) is considered today to be a fundamental principle in analysis of porous media flows (e.g., McWhorter and Sunada, 1977). If, indeed, Darcy’s experimental result is the birth of quantitative hydrology, a need still remains to build quantitative analysis of porous media flow on a strong theoretical foundation. The problem of unsaturated flow of water has been attacked using experimental and theoretical tools since the early part of this century. Sposito (1986) attributes the beginnings of the study of soil water flow as a subdiscipline of physics to the fundamental work of Buckingham (1907), which uses a saturation-dependent hydraulic conductivity and a capillary potential for the hydraulic gradient.
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Carlin, Richard, e Ken Bloom. "Lean Times to Revival". In Eubie Blake, 315–40. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190635930.003.0011.

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This chapter explores the beginnings of the rediscovery of early jazz and blues musicians by a dedicated band of collector/scholars; Rudi Blesh and Harriet Jans’s research on early ragtime that led them to Eubie; Blake’s partnership with Flournoy Miller to write Hit the Stride (not produced) and Brown Skin Models of 1955, staged as a touring show by Miller’s brother Irvin; and Flournoy Miller and Noble Sissle’s continuing attempts to revive the original Shuffle Along. The chapter also examines the ragtime revival that led to Blake recording two albums for 20th Century Fox with a small Dixieland jazz-flavored ensemble; his appearance at the 1960 Newport Jazz Festival; and how he met ragtime revivalist Bob Darch, leading to a few appearances and a mid-1960s recording. Finally, the chapter discusses John Hammond’s interest in recording Blake and how the recording and success of The Eighty-Six Years of Eubie Blake kick-started Eubie’s late career.
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Hassan, Mohsan. "Measurement of Heat and Mass Flow Characteristics of Nanofluid in a Porous Parallel-Plate Channel by Darcy-LTNE/LTE, Brinkman-LTNE/LTE Models". In Nanofluid Flow in Porous Media. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.83482.

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Alicki, Wiesław. ""Jam człowiek, co zaznał boleści" (Lm 3,1) : próba rekonstrukcji starotestamentalnego modelu antropologii na podstawie Lm 3, 1-33". In "Dzięki Bogu za Jego dar niewypowiedziany" (2 Kor 9, 15) Boże dary i ludzka odpowiedź : prace osób związanych z Katedrą Teologii Biblijnej, 43–51. Uniwersytet Papieski Jana Pawła II w Krakowie. Wydawnictwo Naukowe, 2020. http://dx.doi.org/10.15633/9788374388764.03.

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Atti di convegni sul tema "Modèle Darcy"

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Böhle, M., Y. Gu e A. Schimpf. "Two Flow Models for Designing Hydrostatic Bearings With Porous Material". In ASME-JSME-KSME 2019 8th Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ajkfluids2019-4657.

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Abstract The numerical prediction of load capacity, stiffness, power loss of hydrostatic journal bearings must be performed for technical applications. In this contribution hydrostatic bearings consisting of porous material are considered. Porous hydrostatic bearings have the advantage that no pressure erosion occurs and that the flow medium can be led homogenously to the gap between shaft and bearing. It is still a problem to design such bearings because the flow in the porous material must be taken into account. There is a simple flow model (SFM) available to calculate quickly the load capacity, stiffness, power loss. This model which is based on the assumption that the flow inside the porous material is axially symmetric works well provided that the eccentricity is small (dimensionless eccentricity e/h0 < 0.5). For large eccentricities — larger than e/h0 > 0.5 the axially symmetric assumption is too strong violated and the results for load capacity, stiffness become inaccurate. Therefore an improved model was developed which is described in the present contribution. This improved model couples the Reynolds equation for hydrodynamic lubrication (REHL) with Darcy Law as it had already been done for the aforementioned fast working SFM. The improved model is not based on the axially symmetric assumption but models the flow completely inside the porous material, i.e. Darcys Law is applied for the porous material without making any assumptions. By the application of the new model, its short name is Full Darcy’s Law (FDL) Model, bearings with high eccentricities can be designed. The application of Darcys Law leads to a Laplace equation for the static pressure distribution in the porous material which is coupled with the REHL. It is described how the resulting equation system is solved by a finite difference method. In this contribution the fast working SFM is described shortly again. The main emphasis lies on the introduction of the FDL-model which needs more computer resources for designing a porous bearing than the SFM. It is explained in detail how the coupling between Darcy Law (Laplace equation) and the REHL is realized. A comparison between the results of both models is shown and the differences are interpreted. Additionally, CFD results are used in order to validate the results of the FDL-model.
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Belhaj, Hadi, Shabbir Mustafiz, Fuxi Ma, M. Satish e M. R. Islam. "Modeling Horizontal Well Oil Production Using Modified Brinkman’s Model". In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81726.

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Horizontal well oil production has been numerically studied by using the Modified Brinkman’s Model. This model has been used along with the Darcy-Weisbach pipe flow equation in modeling of coupled porous medium/pipe flow. The results include seepage flow rate along the horizontal well, velocity distribution, pressure drop, and production pressure drop between the two ends of the horizontal well. They have been compared with those from Darcy model. It is found that when the fluid’s viscosity is low, there is a big difference between the results from the two models. However, when the fluid’s viscosity is high, the difference tends to vanish. In addition, two striking findings have been observed: (a) the curves for the distribution of the seepage flow rate along the pipeline are more flat than that from Darcy model. However, a higher viscosity makes the curve more uneven. This reverses the trend from Darcy model. (b) The velocity in the pipe is more uniform by MBM than that by Darcy model. The curves of V ~x become more uniform in the pipe when the fluid has a lower viscosity. This again reveres the trend from the Darcy model.
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Li, Dachang, Corneliu-Liviu Ionescu, Ivbade Thaddeus Ehighebolo, Byron Haynes Jr., Ainur Zhazbayeva, Bakyt Yergaliyeva e Luigi Francia. "Modeling and Simulation of Non-Darcy or Turbulent Flow for Oil Wells". In SPE Annual Caspian Technical Conference. SPE, 2022. http://dx.doi.org/10.2118/212067-ms.

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Abstract Modeling and simulation of non-Darcy or turbulent flow are well documented in the literature and available in commercial reservoir simulators (E300, Intersect) only for gas wells rather than oil wells. There is a need to model non-Darcy or turbulent flow in reservoir simulation for oil wells in the carbonate reservoirs with highly connected and densely distributed fractures and karst. This paper proposes a new non-Darcy or turbulent flow modeling and simulation method for oil wells. Unlike the industry's existing methods for non-Darcy or turbulent flow that focus on the non-Darcy coefficient only, this paper presents a new method that models the ratio between non-Darcy and Darcy flows such that a unified model for a field or a region can be created, which significantly simplifies the non-Darcy or turbulent flow modeling process for multiple wells, especially for future wells. The ratio-based method is simple and comprehensive. It can be easily calibrated with MRT (multiple-rate test) data and implemented into in-house or commercial reservoir simulators using a simulator supported scripting language, e.g., Python etc. Kashagan is the world's largest oil reservoir discovered in the last 30 years that contains highly connected and densely distributed fractures and karst in its rim. The oil production rate for a well in the rim can be higher than several tens KSTB/D if it is not constrained by the facility. The current MRT data in all tested wells clearly show non-Darcy flow phenomenon and confirm that modeling non-Darcy flow is necessary to the field. Kashagan had experienced difficulties to match BHP (bottom hole pressure) and large errors in the blind test due to the OPEC's production curtailment and high-rate tests. Build-up pressure curves were miss-matched and HM (history match) of the crossflows (10 KSTB/D with less than 10 psi) in the bottomhole of a PLT (production logging tool) well during shut-in was challenging. Since modeling non-Darcy flow for oil wells in the commercial simulators, e.g., E300 and Intersect, is unavailable, the simulation team in NCOC has created a new method for the needs of non-Darcy modeling and simulation. The applications of the new method have resulted in the excellent results and solved the issues of history matching BHP, high/low-rate tests, build-up pressure trends, and bottomhole crossflows.
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4

LOMBARDO, S., e G. MULONE. "DOUBLE-DIFFUSIVE CONVECTION IN POROUS MEDIA: THE DARCY AND BRINKMAN MODELS". In Proceedings of the 11th Conference on WASCOM 2001. WORLD SCIENTIFIC, 2002. http://dx.doi.org/10.1142/9789812777331_0035.

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5

Murty, V. Dakshina. "A Numerical Simulation of Heat Pipe Application to the Cooling of Pulse Detonation Engines". In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45706.

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A numerical method based on the finite elements is applied to the cooling of pulse detonation tube using heat pipe technology. Towards this end, the fluid flow and heat transfer in the wick are modeled as flow in a porous medium. The flow is described using the so called Darcy Brinkman model which has close resemblance to the Navier-Stokes equations. It is found that for Darcy numbers less than 0.0001 the results are indistinguishable from regular Darcy flows. The shape of the heat pipe is that of a fin with the proportion of the length of the evaporator section being varied. In this study two values of this ratio have been used, namely 1 and 0.5.
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6

Kuru, Azem, e Mehmet Ali Yüzer. "URBAN GROWTH MODELLING AND 3D URBAN GROWTH MODELS". In DARCH 2021- 1st International Conference on Architecture & Design. International Organization Center of Academic Research, 2021. http://dx.doi.org/10.46529/darch.202118.

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Kuru, Azem, e Mehmet Ali Yüzer. "URBAN GROWTH MODELLING AND 3D URBAN GROWTH MODELS". In DARCH 2021- 1st International Conference on Architecture & Design. International Organization Center of Academic Research, 2021. http://dx.doi.org/10.46529/darch.202137.

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8

Saboorian-Jooybari, Hadi, e Peyman Pourafshary. "Non-Darcy Flow Effect in Fractured Tight Reservoirs: How Significant Is It at Low Flow Rates and Away from Wellbores?" In SPE Middle East Unconventional Resources Conference and Exhibition. SPE, 2015. http://dx.doi.org/10.2118/spe-172948-ms.

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Abstract Reservoir development is increasingly moving towards unconventional resources such as tight reservoirs due to the rapid decline in conventional reserves. Several researches have been done in the petroleum industry addressing significant influence of non-Darcy flow behavior on well deliverability and reservoir performance. In all of the previous works, it is generally believed that the non-Darcy flow in a reservoir, if occurs, becomes considerable within a few feet around the wellbores beyond which it is negligible. Furthermore, when mentioned non-Darcy effect in the literature, attentions are usually attracted to gas wells with high production rates (i.e. rates higher than 10 MMSCF / day). In this paper, correlations that are typically used for determination of non-Darcy coefficient are reviewed. Then, it is shown that the correlations are distinct and lead to considerably different values of the non-Darcy coefficient for the same rock sample. A simple guideline is also presented for choosing the most appropriate correlation for a reservoir. Main body of this paper is directed at accurate description of non-Darcy flow in fractured tight reservoirs. This study evaluates the validity of a widely accepted assumption, which considers non-Darcy effect significant only within a few feet around wellbore of gas wells producing at high rates. A synthetic simulation model is made using the data of a well from one of the Iranian fractured tight reservoirs. A full feature compositional simulator is used for the computations in this study. The distance out of the wellbore is subdivided into a number of regions, and then the necessity of including the non-Darcy component in each of the regions for better performance predictions is investigated. The effect of accounting the non-Darcy term in each of the regions on the simulation results such as production rate, final recovery and pressure behavior is studied. Furthermore, three distinct reservoir fluid types including dry gas, gas condensate and black oil are used with the objective well model to evaluate dependence of non-Darcy effect on the type of flowing fluid. The study results are used to provide guidelines about the necessity of global consideration of the non-Darcy term in simulation of different fluid systems even at low production rates. The results highlight that contribution of the non-Darcy component to flow can be significant even far away from wellbores, thus it must be considered globally in the bulk of reservoirs. Additionally, the study demonstrates that the role of non-Darcy component can be crucial even at low production rates regardless of reservoir fluid type. Therefore, in order to have accurate modeling, design and successful implementation of projects, simulations of fractured tight reservoirs must be performed with the global inclusion of the non-Darcy flow formulations regardless of the type of flowing stream and levels of production rate.
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9

Izumi, Tomoki, e Naoyuki Yamashita. "Numerical models for non-Darcy flow based on Forchheimer’s law and Izbash’s law". In Proceedings of the 39th IAHR World Congress From Snow to Sea. Spain: International Association for Hydro-Environment Engineering and Research (IAHR), 2022. http://dx.doi.org/10.3850/iahr-39wc2521711920221380.

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Civan, Faruk. "Predictive Models for Filter Cake Buildup and Filtrate Invasion with Non-Darcy Effects". In SPE Mid-Continent Operations Symposium. Society of Petroleum Engineers, 1999. http://dx.doi.org/10.2118/52149-ms.

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Rapporti di organizzazioni sul tema "Modèle Darcy"

1

Lohne, Arild, Arne Stavland, Siv Marie Åsen, Olav Aursjø e Aksel Hiorth. Recommended polymer workflow: Interpretation and parameter identification. University of Stavanger, novembre 2021. http://dx.doi.org/10.31265/usps.202.

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Injecting a polymer solution into a porous medium significantly increases the modeling complexity, compared to model a polymer bulk solution. Even if the polymer solution is injected at a constant rate into the porous medium, the polymers experience different flow regimes in each pore and pore throat. The main challenge is to assign a macroscopic porous media “viscosity” to the fluid which can be used in Darcy law to get the correct relationship between the injection rate and pressure drop. One can achieve this by simply tabulating experimental results (e.g., injection rate vs pressure drop). The challenge with the tabulated approach is that it requires a huge experimental database to tabulate all kind of possible situations that might occur in a reservoir (e.g., changing temperature, salinity, flooding history, permeability, porosity, wettability etc.). The approach presented in this report is to model the mechanisms and describe them in terms of mathematical models. The mathematical model contains a limited number of parameters that needs to be determined experimentally. Once these parameters are determined, there is in principle no need to perform additional experiments.
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