Dissertations / Theses: 'Fluid analogue'

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Christy, John Randal Ernest. "An investigation of fluid mechanical influences on the clotting of a blood analogue fluid." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/13391.

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Kampman, Niko. "Fluid-rock interactions in a carbon storage site analogue, Green River, Utah." Thesis, University of Cambridge, 2011. https://www.repository.cam.ac.uk/handle/1810/244506.

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Reactions between CO2-charged brines and reservoir minerals might either enhance the long-term storage of CO2 in geological reservoirs or facilitate leakage by corroding cap rocks and fault seals. Modelling the progress of such reactions is frustrated by uncertainties in the absolute mineral surface reaction rates and the significance of other rate limiting steps in natural systems. This study uses the chemical evolution of groundwater from the Jurassic Navajo Sandstone, part of a leaking natural accumulation of CO2 at Green River, Utah, in the Colorado Plateau, USA, to place constraints on the rates and potential controlling mechanisms of the mineral-fluid reactions,under elevated CO2 pressures, in a natural system. The progress of individual reactions, inferred from changes in groundwater chemistry is modelled using mass balance techniques. The mineral reactions are close to stoichiometric with plagioclase and K-feldspar dissolution largely balanced by precipitation of clay minerals and carbonate. Mineral modes, in conjunction with published surface area measurements and flow rates estimated from hydraulic head measurements, are then used to quantify the kinetics of feldspar dissolution. Maximum estimated dissolution rates for plagioclase and K-feldspar are 2x10-14 and 4x10-16 mol·m-2·s-1, respectively. Fluid ion-activity products are close to equilibrium (e.g. DGr for plagioclase between -2 and -10 kJ/mol) and lie in the region in which mineral surface reaction rates show a strong dependence on DGr. Local variation in DGr is attributed to the injection and disassociation of CO2 which initially depresses silicate mineral saturation in the fluid, promoting feldspar dissolution. With progressive flow through the aquifer, feldspar hydrolysis reactions consume H+ and liberate solutes to solution which increase mineral saturation in the fluid and rates slow as a consequence. The measured plagioclase dissolution rates at low DGr would be compatible with far-from-quilibrium rates of ~1x10-13 mol·m-2·s-1 as observed in some experimental studies. This suggests that the discrepancy between field and laboratory reaction rates may in part be explained by the differences in the thermodynamic state of natural and experimental fluids, with field-scale reactions occurring close to equilibrium whereas most laboratory experiments are run far-from-equilibrium. Surface carbonate deposits and cementation within the footwall of the local fault systems record multiple injections of CO2 into the Navajo Aquifer and leakage of CO2 from the site over ca. 400,000 years. The d18O, d13C and 87Sr/86Sr of these deposits record rapid rates of CO2 leakage (up to ~1000 tonnes/a) following injection of CO2, but rates differ by an order of magnitude between each fault, due to differences in the fault architecture. Elevated pCO2 enhances rates of feldspar dissolution in the host aquifer and carbonate precipitation in fracture conduits. Silicate mineral dissolution rates decline and carbonate precipitation rates increase as pH and the CO2 charge dissipate. The Sr/Ca of calcite cements record average precipitation rates of ~2x10-6 mol/m2/s, comparable to laboratory derived calcite precipitation rates in fluids with elevated Mn/Ca and Fe/Ca, at cc of ~1 to 3. This suggests that far-from-equilibrium carbonate precipitation, which blocks fracture conduits and causes the leaking system to self-seal, driven by CO2 degassing in the shallow subsurface, can be accurately modeled with laboratory derived rates. Sandstones altered in CO2 leakage conduits exhibit extensive dissolution of hematite grain coatings and are chemically bleached as a result. Measurements of Eh-pH conditions in the modern fluid, and modeling of paleo-Eh-pH conditions using calcite Fe and Mn concentrations, suggests that the CO2-charged groundwaters are reducing, due to their low dissolved O2 content and that pH suppression due to high pCO2 is capable of dissolving and transporting large concentrations of metals. Exhumed paleo-CO2 reservoirs along the crest of the Green River anticline have been identified using volatile hosting fluid inclusions. Paleo-CO2-charged fluids mobilized hydrocarbons and CH4 from deeper formations, enhancing the reductive dissolution of hematite, which produced spectacular km-scale bleached patterns in these sediment.

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Gilbert, Andrew. "Crystal mobilisation in convecting magma chambers : an analogue experimental approach." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267176.

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Solidified igneous intrusions from originally liquid magma chambers display a large number of different sedimentary features. These features include the gravitational collapse of sidewalls producing slumps and the layering produced by gravitational settling of crystals. In the chamber fluid-dynamic processes such as convection are expected to occur due to cooling at the roof producing dense gravitationally unstable liquid, and the crystallisation of interstitial liquid changing the composition of the remaining liquid possibly reducing the density causing the liquid to rise up. The crystals which form in basaltic magma chambers have a high propensity to be mobilised due to convection and other fluid-dynamic processes including replenishment by a secondary intrusion. Convective mobilisation of plagioclase grains in vertical, tabular intrusions is seen from flat profiles of apparent aspect ratio as a function of dyke width. These flat profiles were formed due to scouring of gravitationally unstable sidewall mushes, and these crystals then become entrained in the convecting liquid. Convection only ceases once the volume of crystals in suspension reaches a critical volume fraction leading to an increase in viscosity, which dampens the vigour of convection. The majority of this study is performing and analysing a number of different experiments to look at the behaviour of different styles of analogue particle piles. Particle piles that are formed of inert, plastic particles are subjected to convection in the particle layer and in the bulk overlying fluid, and different styles of mobilisation depending on the heat flux driving convection and the density profile of the pile are observed. The mobilisation style goes from rolling of particles on the surface, to puffs of particles from the surface being lofted into the interior, followed by large particle fountains and then the entire particle pile being completely disaggregated and lofted into the interior of the chamber as the force driving convection is increased. The initiation of mobilisation can be explained by the fluidisation of a particle pile, whilst the high degrees of mobilisation seen in some high Rayleigh number regimes can be explaining by resuspending particles. In experiments where particle piles have a positive density profile (dense particles overlying low density particles) the underlying low density particles can break through the overlying layer in particle fountains and can be explained by a modified fluidisation parameter. These experiments lack the reactivity and cohesion that realistic crystal piles would have. To try and quantify this, I have also performed a series of experiments looking at the rheology of an ice-sucrose suspension, where ice crystals can sinter and aggregate together. Under sheared conditions the forces required to disaggregate ice aggregates can be calculated, with the viscosity of an ice-sucrose suspension being described by a power-law relationship of shear rate and crystal radius. The particle pile experiments show that mobilisation of equivalent crystal piles in magma chambers should be readily observed. As it is not observed, except in replenished magmatic systems, this suggests that the additional forces coming from cohesion and aggregation in crystal piles prevent mobilisation of magmatic crystals. The replenishment by secondary intrusions can lead to forces which overcome the strength of the pile.

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Shah, Ashish, and ashishshah7@yahoo co in. "Rheology of Shear Thickening Mineral Slurries." RMIT University. Civil, Environmental and Chemical Engineering, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080725.133946.

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Abstract In order to improve the optimisation of mineral processing operations the rheological properties of slurries must be determined as accurately as possible under the conditions that closely resemble actual site conditions. The rheology of particles suspended in Newtonian fluids is well documented. However, the rheology of particles in non-Newtonian fluids has not been the subject of much investigation till now. The work conducted here attempts to fill this gap in knowledge. The rheological properties of slurries are heavily dependent on the solids concentrations and particle-solid interaction. At low solids concentrations, constant viscosity and Newtonian behaviour is observed, but as solids concentration increases the rheological behaviour becomes increasingly complex and non-Newtonian with viscosity becoming dependent on the shear rate. The nature of the non-Newtonian behaviour depends on the solid concentration, particle shape, particle size, particle size distribution and the suspending liquid rheological properties. The suspension/slurry may develop a yield stress and become time dependent in nature as structures develop within the fluid at higher solids concentrations. This study however, is primarily focused on the measurement of the rheological properties, where it is assumed that the fluid will be fully sheared and that the rheological properties will be unlikely to change with time. Shear thickening behaviour of slurries was the focus of this work. The aim was to investigate the slurry concentration region where shear thickening occurs. The first objective of the project was to develop a fluid analogue which will have similar rheological behaviour to that of concentrated tailings from gold mines so that it can be used as a test material to simulate the flow behaviour of the tailings in a pipe. The second objective of this project was to enable the prediction of flow behaviour in the pipe loop under certain conditions using the fluid analogue for slurry from Sunrise dam. In order to achieve the objectives, experiments were carried out to obtain a fluid analogue of a shear thickening slurry. CSL 500 and SR 200 rheometers were used for the characterisation of different fluid analogues and shear thickening mineral slurries. Malvern Sizer, model: mastersizerX v1.1, was used to obtain particle size distributions. A mini pipe loop system, located in the laboratory of the Rheology and Materials Processing Centre (RMPC) was used to get pipe line flow data for comparison with the rheometer data. A few fluid analogues with different suspending medium and different concentrations of glass spheres was tested before finally using, 48 vol% glass spheres in 1.8 wt% CMC solution as a fluid analogue for the mineral tailings obtained from Sunrise dam, WA. For comparison between the pipe line and rheometer data, all pipe line data (in the form of 8V/D) were converted to rheometer data (in the form of du/dr) using the Robinowitsch-Mooney equation. The above comparison indicated that it is possible to produce fluid analogue to simulate the flow behaviour of Sunrise dam slurry using a shear thinning suspending medium with high concentration of glass particles. Shear thickening flow behaviour was clearly observed in the rheometer while it was less predominant in a pipe line flow.

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Maccaferri, Francesco <1980&gt. "Numericals and analogue models of fluid-filled fractures propagation in layered media: application to dikes and hydrofractures." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2938/.

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Young, Roland Michael Brendon. "Predictability of a laboratory analogue for planetary atmospheres." Thesis, University of Oxford, 2009. http://ora.ox.ac.uk/objects/uuid:b4f483a6-437c-4914-b94e-cb04d996b337.

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The thermally-driven rotating annulus is a laboratory experiment used to study the dynamics of planetary atmospheres under controlled and reproducible conditions. The predictability of this experiment is studied by applying the same principles used to predict the atmosphere. A forecasting system for the annulus is built using the analysis correction method for data assimilation and the breeding method for ensemble generation. The results show that a range of flow regimes with varying complexity can be accurately assimilated, predicted, and studied in this experiment. This framework is also intended to demonstrate a proof-of-concept: that the annulus could be used as a testbed for meteorological techniques under laboratory conditions. First, a regime diagram is created using numerical simulations in order to select points in parameter space to forecast, and a new chaotic flow regime is discovered within it. The two components of the framework are then used as standalone algorithms to measure predictability in the perfect model scenario and to demonstrate data assimilation. With a perfect model, regular flow regimes are found to be predictable until the end of the forecasts, and chaotic regimes are predictable over hundreds of seconds. There is a difference in the way predictability is lost between low-order chaotic regimes and high-order chaos. Analysis correction is shown to be accurate in both regular and chaotic regimes, with residual velocity errors about 3-8 times the observational error. Specific assimilation scenarios studied include information propagation from data-rich to data-poor areas, assimilation of vortex shedding observations, and assimilation over regime and rotation rate transitions. The full framework is used to predict regular and chaotic flow, verifying the forecasts against laboratory data. The steady wave forecasts perform well, and are predictable until the end of the available data. The amplitude and structural vacillation forecasts lose quality and skill by a combination of wave drift and wavenumber transition. Amplitude vacillation is predictable up to several hundred seconds ahead, and structural vacillation is predictable for a few hundred seconds.

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Aruquipa, David Quispe 1989. "An analogue model of gravity based on a radial fluid flow : the case of AdS and its deformations = Um modelo análogo à gravitação baseado em um fluxo radial: o caso do espaço-tempo AdS e suas deformações." [s.n.], 2017. http://repositorio.unicamp.br/jspui/handle/REPOSIP/325326.

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Orientadores: Ricardo Antonio Mosna, Márcio José Menon
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin
Made available in DSpace on 2018-09-02T03:12:41Z (GMT). No. of bitstreams: 1 QuispeAruquipa_David_M.pdf: 2372918 bytes, checksum: bb030f9f8aecc210d608f2f9005a7a49 (MD5) Previous issue date: 2017
Resumo: Os modelos análogos são uma ferramenta muito útil quando se quer entender ou testar fenômenos em um sistema físico em termos e conceitos de outro, esses sistemas podem ser mais familiares ou mais facilmente reproduzíveis por experimentos. Este trabalho explora esta questão no contexto de modelos análogos à gravitação baseados na mecânica dos fluidos. Particularmente, estamos interessados em fornecer um modelo análogo para um fluxo radial com uma fonte/sorvedouro na origem. Começamos por considerar o caso em que a velocidade do fluxo (radial) é constante. O modelo análogo resultante é então o espaço-tempo Anti-de Sitter (ou AdS) que é conhecido por ser não-globalmente hiperbólico. Como resultado, a dinâmica dos campos neste contexto não está bem definida até que sejam estabelecidas condições adicionais na fronteira no infinito espacial do espaço-tempo AdS. A contrapartida destas condições de fronteira extra na mecânica dos fluidos proporciona uma descrição efetiva da fonte/sorvedouro que está na origem. Depois disso, nós consideramos regularizações para o modelo análogo perto da fonte/sorvedouro na origem. Logo, impomos condições sobre eles, a fim de que a dinâmica seja bem definida de modo que não são mais necessárias as condições na fronteira. Calculamos como as quantidades físicas, como a diferença de fase entre as ondas que entram e saem, são afetadas pelas regularizações. Estes resultados são então comparados com o caso AdS para compreender as principais implicações do processo de regularização, que tem o efeito de deformar a região perto do infinito espacial do AdS. Mostramos também que, sob certas condições, a diferença de fase obtida para esses espaços deformados do AdS coincide com a obtida no caso do espaço-tempo AdS
Abstract: Analogue models are a useful tool when one wants to understand or probe phenomena in one physical system in terms of concepts from another, which may be more familiar or more easily accessed by experiments. This work explores this framework in the context of analogue models of gravity based on fluid dynamics. Particularly, we are interested in providing an analogue model for a radial fluid flow with a point source/sink at the origin. We start by considering the case where the (radial) flow velocity is constant. The resulting analogue model is then the Anti-de Sitter spacetime (AdS) which is known to be non-globally hyperbolic. As a result, the dynamics of fields in this background is not well defined until extra boundary conditions at its spatial boundary are prescribed. The fluid dynamics counterpart of these extra boundary conditions provide an effective description of the point source/sink at the origin. After that, we consider regularizations of this model near the source/sink at the origin. We then impose conditions on them in order that the dynamics is well defined so that no extra boundary conditions are required. We calculate how physical quantities, like the phase difference between ingoing and outgoing scattered waves are affected by the regularizations. These results are then compared with the AdS case to understand the main implications of the regularization, which has the effect of deforming the AdS space near its spatial infinity. We also show that, under certain conditions, the phase difference obtained for these deformed AdS spaces agrees with that obtained in the AdS case
Mestrado
Física
Mestre em Física
1490213/2015
CAPES

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Yuan, Xiaoping. "Extensional collapses in the overpressured frictional upper crust based on limit analysis." Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEE009/document.

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Dans ce manuscrit nous développons l'approche cinématique 2D du calcul à la rupture pour examinerles effondrements en extension (ou failles normales) de la croûte supérieure cassante qui résultent desurpressions de fluides. Les sujets d'intérêt liés à la déformation en extension sont (1) les roles de lapression des fluides, des processus de surface, et des propriétés des matériaux et des failles sur lastabilité des structures d'extension; (2) la formation de failles normales à faible pendage et de failleslistriques; (3) la distribution de la déformation au dessus d'un glissement à faible pendage; et (4)l'influence de l'adoucissement mécanique des failles et des processus de sédimentation sur cettedistribution.Cette approche mécanique est vérifiée par la théorie du prisme critique de Coulomb, et la généralise pour étudier la topographie complexe de la péninsule de Mejillones dans le Nord du Chili. Cetteapproche est aussi appliquée à l'instabilité gravitaire dans le delta du Niger en reliant les structurescompressives en bas de pente aux structure extensives en amont par un détachement profond. Nousprédisons des surpressions de fluides beaucoup plus élevée que celles obtenues par application duprisme de Coulomb. Enfin, cette méthodologie est appliquée à l'étude de la forme de failles normalesreliant un détachement profond à la surface. Dans le cas du delta du Niger, nous montrons que lesfailles à faible pendage et les failles listriques impliquent que la profondeur de rétention des fluides estfaible. La version séquentielle de l'analyse limite ouvre de nouvelles voies pour suivre l'évolutionstructurale dans le temps du jeu sur les failles normales. Les simulations montrent en particulier qu'unefaille normale tourne vers des pendage plus faibles au fur et à mesure de la dénudation du mur, formantune région qui passe du mur au toit de la faille active en rotation. La prédiction de cette région estillustrée par des expériences analogiques et des exemples de terrain
This manuscript develops a 2D kinematic approach of Limit Analysis to examine the extensionalfailures in the brittle, upper crust resulting from fluid overpressures and normal faulting. There aremany interesting topics related to the extensional deformation such as (1) the roles of fluid pressure,topographic process, material and fault properties on the stability of extensional structures; (2) theformation of low-angle and listric normal fault; (3) the deformation pattern due to slip on a low-anglefault; and (4) the influence of fault softening and sedimentation processes on this deformation pattern.This mechanical approach applied to wedge prototypes is validated by the critical Coulomb wedge(CCW) theory, and it generalizes the CCW theory to investigate the complex topography on theMejillones peninsula, Northern Chile. Additionally, this approach is also applied to investigate gravityinstability of Niger Delta by linking down-slope compressional to up-slope extensional failures througha deep detachment. We predict much higher fluid overpressures than that of the CCW theory. Finally,this Limit Analysis methodology is applied to investigate the shape of normal fault linking a lowdetachment to the surface. The application to Niger Delta implies that the formation of very low-angleand strongly listric faults results from a shallow fluid-retention depth. The sequential version of LimitAnalysis opens new ways to envision the structural evolution through time resulting from normalfaulting. The simulations show that the normal fault rotates during extension, forming a region of Footto-Hanging Wall (FHW) where the material in the footwall is sheared upon entering the hanging wall.The creation of the FHW region is illustrated by sandbox experiments and field examples

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Green, Douglas Andrew. "Analogue measurement of scattered light fluctuations." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/11102.

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This thesis investigates two methods of optical analysis of multiphase fluids. These two methods are nephelometry and the statistical analysis of scattered light intensity fluctuations. Nephelometry is an established technique for investigating particulate suspensions. In this work the basic technique is combined with neural network processing to develop a system capable of automatically distinguishing and quantifYing different suspensions, in particular suspensions of oil. Evidence obtained in this study suggests that neural networks can distinguish the light scattering from suspensions of different size distributions and produce a more accurate estimate of volume fraction than commonly used turbidity measurements. Non-Gaussian, fluctuating light intensities arise from the scattering of light from a varying population of suspended particles. Successful measurement of these intensity fluctuations makes feasible new instrumentation based on the statistical behaviour of the detected signal. Analyses that could prove possible include particle number, size, type and flow characteristics. Photon counting methods have traditionally been used to measure fluctuations from random media but the lower cost of analogue pin diodes makes them the preferred choice of detector if they can be applied usefully. A method of quantifYing the effect of noise from the diode detectors and removing it from the statistics of the fluctuations is developed from a model of the pin diode detectors. Experimental results show that detector noise can be compensated for in the analysis of scattered light fluctuations. Results also indicate that the model used to describe the scattering process is valid and that further work can lead to a practical instrument for the study of suspensions.

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Schmatz, Joyce [Verfasser]. "Grain-boundary – fluid inclusion interaction in rocks and analogues / Joyce Schmatz." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2011. http://d-nb.info/101649324X/34.

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Da, Silva Soares Ana. "Fluid queues: building upon the analogy with QBD processes." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211053.

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Les files d'attente fluides sont des processus markoviens à deux dimensions, où la première composante, appelée le niveau, représente le contenu d'un réservoir et prend des valeurs continues, et la deuxième composante, appelée la phase, est l'état d'un processus markovien dont l'évolution contrôle celle du niveau. Le niveau de la file fluide varie linéairement avec un taux qui dépend de la phase et qui peut prendre n'importe quelle valeur réelle.

Dans cette thèse, nous explorons le lien entre les files fluides et les processus QBD, et nous appliquons des arguments utilisés en théorie des processus de renouvellement pour obtenir la distribution stationnaire de plusieurs modèles fluides.

Nous commençons par l'étude d'une file fluide avec un réservoir de taille infinie; nous déterminons sa distribution stationnaire, et nous présentons un algorithme permettant de calculer cette distribution de manière très efficace. Nous observons que la distribution stationnaire de la file fluide de capacité infinie est très semblable à celle d'un processus QBD avec une infinité de niveaux. Nous poursuivons la recherche des similarités entre les files fluides et les processus QBD, et nous étudions ensuite la distribution stationnaire d'une file fluide de capacité finie. Nous montrons que l'algorithme valable pour le cas du réservoir infini permet de calculer toutes les quantités importantes du modèle avec un réservoir fini.

Nous considérons ensuite des modèles fluides plus complexes, de capacité finie ou infinie, où le comportement du processus markovien des phases peut changer lorsque le niveau du réservoir atteint certaines valeurs seuils. Nous montrons que les méthodes développées pour des modèles classiques s'étendent de manière naturelle à ces modèles plus complexes.

Pour terminer, nous étudions les conditions nécessaires et suffisantes qui mènent à l'indépendance du niveau et de la phase d'une file fluide de capacité infinie en régime stationnaire. Ces résultats s'appuient sur des résultats semblables concernant des processus QBD.

Markov modulated fluid queues are two-dimensional Markov processes, of which the first component, called the level, represents the content of a buffer or reservoir and takes real values; the second component, called the phase, is the state of a Markov process which controls the evolution of the level in the following manner: the level varies linearly at a rate which depends on the phase and which can take any real value.

In this thesis, we explore the link between fluid queues and Quasi Birth-and-Death (QBD) processes, and we apply Markov renewal techniques in order to derive the stationary distribution of various fluid models.

To begin with, we study a fluid queue with an infinite capacity buffer; we determine its stationary distribution and we present an algorithm which performs very efficiently in the determination of this distribution. We observe that the equilibrium distribution of the fluid queue is very similar to that of a QBD process with infinitely many levels. We further exploit the similarity between the two processes, and we determine the stationary distribution of a finite capacity fluid queue. We show that the algorithm available in the infinite case allows for the computation of all the important quantities entering in the expression of this distribution.

We then consider more complex models, of either finite or infinite capacities, in which the behaviour ff the phase process may change whenever the buffer is empty or full, or when it reaches certain thresholds. We show that the techniques that we develop for the simpler models can be extended quite naturally in this context.

Finally, we study the necessary and sufficient conditions that lead to the independence between the level and the phase of an infinite capacity fluid queue in the stationary regime. These results are based on similar developments for QBD processes.
Doctorat en sciences, Spécialisation mathématiques
info:eu-repo/semantics/nonPublished

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Welch, Nathan James. "Imaging and fluid flow measurements of reservoir cap rock and ceramic analogues." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/41985.

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The study of reservoir seal formation characteristics is vital to the success of carbon sequestration projects. The unique properties of these formations allows for the safe long-term storage of carbon dioxide. These intrinsic properties also give rise to numerous experiment complexities outside of the realm of traditional core characterization techniques. Samples were obtained to represent the main classes of cap rocks; shales from both a quarry in the UK and a Spanish carbon storage pilot site, anhydrite from UK extraction mines, and a evaporite sample from a reservoir located in the Middle East. An apparatus has been constructed capable of measuring the permeability and capillary threshold pressure of reservoir cap rocks. The pressure decay technique was used to measure the permeability relationship of clay-rich and evaporite samples with varying applied stresses was measured. Unique trends are observed for each geologic sample exhibiting minimums in permeability. The initial reduction of permeability as effective pressure was increased was due compaction and the subsequent increase at high stresses was due to the opening of micro-fractures. The capillary threshold pressures of each sample were determined using three different techniques. A novel technique takes advantage of the pressure decay permeability measurements technique in quantifying extremely small fluid volumes during initial sample drainage. Capillary threshold pressures were shown to also be dependant on applied system stress. The capillary threshold pressure was observed to decrease dramatically following the increase in permeability with further increasing effective pressure. Imaging capabilities were also explored, ranging from core scale to nanometre scale techniques. Computerized micro-tomography was used in plug sample evaluation, and in the observation of fractured system behaviour under varying stress. Scanning electron microscopy paired with focused ion beam milling was used to extract the 3D pore space of the ceramic allowing for permeability estimates from numerical simulations.

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Hugot, Alexandre. "Modelisation des ecoulements gravitaires catastrophiques par une approche objet dynamique : Erosion - Transport - Depot." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2000. http://tel.archives-ouvertes.fr/tel-00002677.

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Nous proposons dans cette thèse un modèle mathématique simple adapté à la sédimentation des dépôts gravitaires en eaux profondes. L'écoulement est traité comme un objet géométrique déformable. Les principaux mécanismes physiques pris en compte par le modèle sont : 1. La turbulence ; 2. L'étalement dû aux forces de pressions ; 3. L'incorporation de fluide le long de l'interface suspension-fluide ambiant ; 4. La sédimentation de particules ; 5. L'érosion de particules. Les solutions analytiques asymptotiques du système différentiel non-linéaire montrent la consistance des solutions numériques sur les temps longs. Les tests numériques permettent de quantifier l'impact qualitatif et quantitatif des pramètres physiques du modèle, des conditions initiales et des parmètres de contrôle (pente, granulométrie). Une méthode d'inversion est mise en oeuvre pour l'identification des conditions initiales et/ou des paramètres du modèle. L'inversion partielle (détermination des conditions initiales) appliquée à des modèles réduits expérimentaux montre le bon comportement qualitatif du modèle et cela même hors du domaine de validité strict de ce dernier. L'inversion total (identification des paramètres physiques et détermination des conditions initiales) montre le bon comportement du modèle d'un point de vue quantitatif au niveau des vitesses de l'écoulement et des épaisseurs déposées. La méthode d'inversion est appliquée à l'effondrement de l'aéroport de Nice en 1979 pour tester des scénarios d'écoulement. Contrainte par les ruptures de câbles et/ou les épaisseurs déposées, elle permet, par exemple, d'estimer le volume initial ou les paramètres physiques de l'effondrement (coefficient de friction, nombre de Schmidt turbulent modifié...). Malgré quelques limitations, principalement dues aux simplifications géométriques de l'écoulement, ce modèle simple est un premier pas vers la compréhension quantitative de l'impact des paramètres externes -tel que la nature et la quantité des apports en sédiments, la géométrie du bassin- sur la dynamique des courants turbiditiques et l'organisation des séquences de dépôts résultantes. Grâce à ses faibles temps de calcul sur micro-ordinateur, il est envisageable de simuler des séries d'événements et de former ainsi des séquences de dépôt multi-événementielles. Il peut être utilisé pour reconstruire les processus de sédimentation et les dépôts résultants.

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Scotte, Anton, and Emil Zeidlitz. "Investigating the Numerical Applicability of Analogies between Quantum Mechanics and Fluid Mechanics." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-276578.

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MOURGUES, REGIS. "Surpressions de fluide et décollements. Modélisations analogique et numérique." Phd thesis, Université Rennes 1, 2003. http://tel.archives-ouvertes.fr/tel-00007479.

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Les surpressions de fluide sont très souvent invoquées pour expliquer les très faibles frottements observés à la base des nappes chevauchantes ou les glissements de sédiments sur de très faibles pentes. La modélisation analogique ne les avait cependant jamais prises en compte. Dans cette thèse, nous développons une nouvelle technique qui consiste à injecter de l'air dans des modèles de sable afin de simuler ces surpressions. Grâce à cette méthode, nous montrons comment les fluides agissent sur la déformation par l'intermédiaire des forces de courant (gradient de pression), en modifiant l'intensité et l'orientation des contraintes effectives. Nous effectuons ensuite des expériences de déformation compressive, dans lesquelles nous générons des niveaux de décollement en jouant sur la perméabilité du sable utilisé dans la construction des modèles. L'efficacité de ces décollements dépend alors de la pression de fluide appliquée et contrôle le style de la déformation. Ces expériences analogiques sont comparées avec un modèle numérique d'éléments distincts couplé à une phase fluide, que nous avons également développé au cours de cette thèse. La confrontation des résultats issus des deux méthodes apparaît assez convaincante. Nous simulons ensuite des glissements gravitaires et montrons comment les surpressions de fluide peuvent créer des failles normales listriques en modifiant l'orientation des contraintes. Ces expériences sont enfin appliquées aux déformations du delta de l'Amazone. La corrélation entre la forme des glissements, la distribution des pressions et la présence d'une roche mère en probable génération de gaz, nous permet de préciser l'origine des surpressions dans ce delta. Pour terminer, nous nous plaçons à l'échelle du grain de sable, et nous utilisons la méthode numérique pour caractériser l'évolution de la texture d'un milieu granulaire soumis à un gradient de pression de fluide croissant.

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Mourgues, Régis. "Surpressions de fluide et décollements : modélisations analogique et numérique /." Rennes : Éd. de Géosciences-Rennes, 2004. http://catalogue.bnf.fr/ark:/12148/cb39955647q.

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Mourgues, Régis. "Surpression de fluide et décollements : modélisations analogique et numérique." Rennes 1, 2003. https://tel.archives-ouvertes.fr/tel-00007479.

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Les surpressions de fluide sont très souvent invoquées pour expliquer les très faibles frottements observés à la base des nappes chevauchantes ou les glissements de sédiments sur de très faibles pentes. Dans cette thèse, nous développons une méthode analogique qui permet d’introduire ces effets dans des modèles de sable. Nous avons également écrit un code numérique d'éléments distincts couplé avec un fluide. Nous utilisons ces deux méthodes pour montrer comment les fluides agissent sur les déformations par l'intermédiaire des forces de courant qui modifient l'état des contraintes (intensité et orientation). Nous simulons ensuite la formation de prismes d'accrétion soumis à des surpressions de fluide variées. La confrontations des résultats analogiques et numériques est assez convaincante et en accord avec les modèles théoriques. Nous appliquons enfin nos expériences aux déformations gravitaires rencontrées dans le delta de l'Amazone. La corrélation entre la forme des glissements, la distribution des pressions et la présence d'une roche mère en probable génération de gaz, nous permet de préciser l'origine des surpressions dans ce delta.

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Bolland, Scott William. "FAE : the fluid analogies engine : a dynamic, hybrid model of perception and mental deliberation /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18899.pdf.

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Good, Victoria Diane. "The tribological significance of the joint fluid analog in a hip joint simulator." Thesis, University of Strathclyde, 2001. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21422.

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Wear is the number one concern with regards to the longevity of THR (total hip replacement). Therefore, reliable in-vitro prediction of wear is necessary. Thus, the laboratory should first validate their hip simulators with known clinical materials. The limiting factor in hip wear simulation has been the joint fluid analog. Using 100% bovine serum as the joint fluid analog, UHMWPE (ultra-high molecular weight polyethylene) wear-rates have been continually underestimated and PTFE (polytetrafluoroethylene) wear has been overestimated. Therefore, this work investigated the effect of protein concentration in bovine serum on the wear of PTFE and UHMWPE in a biaxial hip joint simulator. Validation criteria were developed based on the clinical findings of: ball size effect of increased wear with increased head size, 6% increase in wear for each millimeter of increased head diameter, clinical wear magnitudes, PTFE/UHWMPE wear-rate ratio and debris morphology. Both materials duplicated the clinical criteria using bovine serum with 10mg/ml of protein concentration. As protein concentration went from 0 to 10mg/ml, wear of both materials increased, however with greater than 10mg/ml protein; a) the rate of increase for PTFE was reduced by 80% and b) the wear of UHMWPE reversed, thus, showing that proteins cause wear. Additionally as the volume of fluid was increased, wear increased. This change in wear with protein concentration and volume was due to a protection of protein precipitate. As protein concentration increased protein precipitation increased and wear was decreased due to a protective layer of precipitates. Furthermore, wear protection was dependent on the amount of protein precipitation which was in turn, dependent on the initial concentration, volume of fluid and time. Therefore, wear in-vitro was dependent on the joint fluid analog. This work proved that the laboratory could duplicate clinical findings using bovine serum with 10mg/ml of protein concentration as the joint fluid analog and thus increase confidence in wear evaluation; taking the first steps to showing reliability of in-vitro THR wear studies.

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Burt, Andrew C. "A computational study of mixing in stratified liquid-liquid flows using analogy between heat and mass transfer." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1948.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains x, 76 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 71-72).

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Schenk, Oliver [Verfasser]. "Grain boundary structure in minerals and analogues during recrystallization in the presence of a fluid phase / Oliver Schenk." Aachen : Shaker, 2006. http://d-nb.info/1170528848/34.

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22

Incerpi, Nicolo. "Hydrothermal systems in distal rifted margins and their role in the thermal evolution of sedimentary successions : study of two fossil analogues in the Swiss Alps and Pyrenees." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAH005/document.

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Les données sismiques et les forages des marges continentales distales permettent de comprendre l'architecture et l'évolution de ces domaines, dont l’évolution thermique est peu connue, même si on connaît que les systèmes hydrothermaux jouent un rôle clé dans la distribution des flux de chaleur. Cette thèse vise à étudier les produits diagénétiques dans les sédiments de pré- à post-rift, qui enregistrent l'évolution des interactions roche-fluide. Deux analogues fossiles ont été étudiés: la marge distale adriatique et le système hyper-étiré pyrénéen. Les études de terrain, pétrographiques et géochimiques révèlent une forte hétérogénéité dans la composition des fluides. Dans les premières phases de rifting, dominées par des failles normales à fort pendage, les fluides sont riches en carbonate,tandis que dans les dernières phases, caractérisées par des failles de détachement à faible pendage qui exhument les roches de la croûte continentale et du manteau, les fluides résultent riches en silice. Cette thèse a donc démontré que l'évolution tectonique des marges de rifting comporte aussi des changements spécifiques dans la chimie des fluides hydrothermaux
Seismic and drill hole data from deep-water distal rifted margins allow to understand the architecture and evolution of these yet little investigated domain. Nonetheless, the thermal evolution is poorly constrained even if hydrothermal systems play a key role in determining the heat fluxes. This Thesis aims to investigate breccias, cements, veins and replacement minerals within the pre- to post-rift sediments that could testify the space-time evolution of rock-fluid interactions. Two fossil analogues are studied: the Adriatic distal margin and the Pyrenean hyper-extended system. Field, petrography and geochemical analyses reveal a strong heterogeneity in the composition of the fluids as well as their hydrothermal features. Two main types of fluids occur: carbonate-rich fluids refer to early rifting phases dominated by high-angle normal faults; silica-rich fluids are related to the last rifting stages characterized by low-angle detachment faults exhuming upper crust and mantle-related rocks. The results of this Thesis highlight how specific changes in the chemistry of the fluid system are intimate lylinked to the tectonic evolution of rifted margins

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Preusse, Franziska. "High fluid intelligence and analogical reasoning." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/16424.

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Hitherto, previous studies on the cerebral correlates of fluid intelligence (fluIQ) used tasks that did not exclusively demand fluIQ, or were restricted to participants of average fluIQ (ave-fluIQ) solving intelligence test items of varying difficulty, thus not allowing assumptions on interindividual differences in fluIQ. Geometric analogical reasoning (GAR) demands fluIQ very purely and thus is an eligible approach for research on interindividual differences in fluIQ. In a first study, we examined the cerebral correlates of GAR, and showed the involvement of parietal and frontal brain regions. This is in line with the assumptions of the parieto-frontal integration theory (P-FIT) of intelligence and with literature reports for other visuo-spatial tasks. Building upon these findings, we report results from a second study with high fluIQ (hi-fluIQ) and ave-fluIQ school students solving a GAR task. Again in line with the P-FIT model, we demonstrated that the parieto-frontal network is involved in GAR in both groups. However, the extent of task-related brain activation in parietal and frontal brain regions was differentially modulated by fluIQ. Our results thus partly run counter to the postulates of the neural efficiency hypothesis, which assumes a negative brain activation-intelligence relationship. We conclude that this relationship is not generally unitary; rather, it can be conjectured that the adaptive and flexible modulation of brain activation is characteristic of hi-fluIQ. Knowledge on the stability of the cerebral correlates of hi-fluIQ during adolescence had been sparse. To elucidate this field, we examined the follow-up stability of the cerebral correlates of GAR in hi-fluIQ in a third study. We demonstrated that the relevant brain network is in place already at age 17 and that improvements in behavioral performance at age 18 due to task familiarity are indicative of more efficient use of the cerebral resources available.
Bisherige Studien zu zerebralen Korrelaten fluider Intelligenz (fluIQ) haben Aufgaben verwendet, die fluIQ nicht in Reinform erfordern oder haben Probanden mit durchschnittlicher fluIQ (ave-fluIQ) beim Lösen von Intelligenztestaufgaben mit variierenden Schwierigkeitsstufen untersucht und ermöglichen daher keine Aussagen zu interindividuellen Unterschieden in fluIQ. Geometrisches analoges Schließen (GA) beansprucht fluIQ in Reinform und eignet sich daher als differentielles Untersuchungsparadigma. In einer ersten Studie haben wir die zerebralen Korrelate des GA untersucht und nachgewiesen, dass parietale und frontale Hirnregionen involviert sind. Dies steht im Einklang mit der parieto-frontalen Integrationstheorie (P-FIT) der Intelligenz und mit Literaturberichten zu anderen visuell-räumlichen Aufgaben. Aufbauend auf diesen Befunden berichten wir Ergebnisse einer zweiten Studie, in der Schüler mit hoher fluIQ (hi-fluIQ) und ave-fluIQ GA-Aufgaben lösten. In Übereinstimmung mit den Annahmen des P-FIT-Modells konnten wir zeigen, dass GA in beiden Gruppen das parieto-frontale Netzwerk beansprucht. Das Ausmaß der Hirnaktivierung wurde jedoch differentiell durch fluIQ moduliert. Unsere Ergebnisse widersprechen damit teilweise den Postulaten der neuralen Effizienztheorie, die einen negativen Zusammenhang zwischen Hirnaktivierung und Intelligenz annimmt. Wir schlussfolgern, dass dieser Zusammenhang nicht generell einseitig gerichtet ist, sondern die flexible Modulation von Hirnaktivierung charakteristisch für hi-fluIQ ist. Befunde zur Stabilität zerebraler Korrelate von hi-fluIQ in der Jugend waren bisher rar. Um dieses Feld zu beleuchten, haben wir die follow-up-Stabilität zerebraler Korrelate des GA in der hi-fluIQ Gruppe in einer dritten Studie untersucht. Wir konnten zeigen, dass das relevante zerebrale Netzwerk schon mit 17 Jahren etabliert ist und Performanzverbesserungen über die Zeit für eine effizientere Nutzung der verfügbaren zerebralen Ressourcen sprechen.

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Sagi, David Adam. "Characterisation of the 2D and 3D density and connectivity attributes of fracture systems in carbonate reservoir analogues : implications for fluid flow." Thesis, Durham University, 2013. http://etheses.dur.ac.uk/6910/.

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Fault zones, hosted in fractured carbonate reservoirs, can behave as either high porosity and permeability conduits, favoring the migration of fluids; or, conversely, as low porosity and permeability barriers, retarding fluid flow, due to the presence of fine-grained fault gouges (Agosta and Aydin, 2006, Agosta and Kirschner, 2003). Due to these reasons, fault zones can have great economical importance for the hydrocarbon industry. Furthermore, within fault zones, the cyclic accumulation and sudden release of trapped, high pressure fluids can trigger earthquakes and aftershocks (Miller et al. 2004). In this project, we referred to the classical fault zone architecture models defined by Sibson (1977) and Chester et al. (1993), in which faults are built up of a fault core (where most of the displacement is localised), a damage zone (containing fractured host rocks) and the protolith (the unfractured host rock). Faults, with displacements ranging from cm- to km-scale have been studied within two study areas, Flamborough Head, UK and the Gubbio fault in the Northern Apennines, Italy. Flamborough Head is a peninsula in East Yorkshire, which represents analogues for hydrocarbon rich, fractured North Sea chalk reservoirs; whereas the Gubbio fault is a regional scale, seismically active normal fault, characterized by complex fault zone architectures, cutting through different types of carbonates. At both study areas, field-based, outcrop-scale structural observations were completed in order to explore the internal architecture and infer the fluid transmissibility of the fault zones. Additionally, microscale structural observations were made using representative thin sections, collected from the different fault zone domains of the studied fault zones. Qualitative structural observations were complemented with quantitative analyses to study the variation of fracture and vein density and connectivity patterns across the fault zones, which were later used as a proxy for fluid transmissibility. These analyses included established 1D (transects) and 2D (image analysis) methods and a newly developed workflow for the modelling of fracture networks in 3D, based on LiDAR data. 3D modelling of fracture networks was developed using different fracture height/length aspect ratios. The quantitative comparison of different aspect ratio 3D models with established 1D and 2D results, by using misfit graphs, enabled to validate the different 3D models and to estimate the mean aspect ratio of fractures within the fault zones. Qualitative and quantitative results were integrated in conceptual fault zone architecture and fluid flow models. At Flamborough Head small (cm-scale) and larger (up to 20 m) displacement normal faults were studied in two different types of chalks: one characterized by cm-scale interlayered marl horizons and another one, absent of it. Within the marl-free host rock, in the fault zones of both the small and the large displacement faults, fluid assisted deformation features, such as veins, are often observed. On the contrary, in marl-rich units, fluid assisted deformation features are absent, while fractures filled with intruded marl from the interlayered horizons are common. This suggests that the occurrence of fluid flow in this lithology is primarily controlled by the protolith. 1D quantitative analysis at Flamborough Head showed that, as also predicted by classical fault zone models, vein density progressively increases in the damage zones of faults moving from the protolith towards the fault core. 2D quantitative analysis showed that fracture connectivity remains as low as background values in the outer parts of the damage zones, whereas it increases rapidly in the inner parts. By comparing the fracture density and connectivity patterns measured from different aspect ratio 3D models with results measured from 1D and 2D analyses showed that the most realistic model is the 1/5 fracture aspect ratio one. The Gubbio fault cuts through a carbonatic multilayer containing carbonates with different marl content. In the Marne a Fucoidi formation marl is homogenously distributed, while in the overlying Scaglia Group marl is absent. Within the damage zone, hosted in the Marne a Fucoidi formation, fluid assisted deformation features are rare and are only present in the damage zones of subsidiary faults that entirely cut through the formation, linking the under and overlying marl free carbonates. On the contrary, within the damage zone, hosted in the Scaglia Group, fluid assisted deformation features are common, especially close to the fault core of the Gubbio fault and in the damage zone of subsidiary faults. Similarly to Flamborough Head, this suggests that the occurrence of fluid flow is primarily controlled by the nature of the protolith. As predicted by classical fault zone models, 1D quantitative analysis across the Gubbio fault showed that vein density increases in the damage zone moving from the protolith towards the fault core. Similarly to results from Flamborough Head, 2D quantitative analysis showed that fracture connectivity is low in the outer parts of the damage zones, but increases rapidly within the inner parts, and the comparison of 3D models with 1D and 2D results showed that the most realistic model is the 1/5 aspect ratio one. The conceptual fluid flow models, built for the study areas, highlights: a) the importance of different marl content host rocks controlling the initiation of fluid flow; b) the development of smaller and larger displacement normal faults and the effects of their displacements on fluid transmissibility; c) the effects of fault damage zones, positioned in an overlapping geometry, resulting in the development high and low fracture connectivity subdomains and fracture corridors; d) the differences in the relative variation of fracture/vein density and connectivity throughout the damage zone compared to background values; e) the fluid transmissibility of the different fault rocks, located within different subdomains of the fault core and f) the anisotropy of fluid transmissibility in the fault core.

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Nishii, Kenichiro. "MICRO-SCALE FLUID DYNAMICS AND ITS EFFECT ON HEPATIC PROGENITOR CELL REGENERATION ACTIVATION." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1461945701.

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Curtis, Daniel J. "Analysis of the Hite Fault Group, Southeast Utah: Insights into Fluid Flow Properties in a Reservoir Analog." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6538.

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In the subsurface faults can act as both barriers and conduits for fluids or gases such as CO2, hydrocarbons, or water. It is often thought that faults in porous rocks such as sandstone are barriers to fluid flow. In this study we show that this is not always the case. In sandstones like the Cedar Mesa Sandstone it is very important to understand the relationships between this history of fault slip and fluid flow. Better understanding of how fluids migrate through faults and the damaged areas surrounding these faults has strong significance to the oil and gas industry. In this study we examine a group of faults and their surrounding damage zones near Hite, Utah. We analyze three of these small-scale faults in more detail. In doing so we give insights into how these faults and their damage zones can effect fluid migration as well as the porosity and permeability in the Cedar Mesa Sandstone. Whole rock geochemistry, X-ray diffraction mineralogy, permeability data, petrography, ultraviolet photography, and outcrop observations were used to gain insights into cross-cutting relationships, past fluid compositions, and fault characteristics. From the data that was collected from these faults we have begun to describe a series of structural and fluid flow events. This series allows us to say that small-scale faults and fractures are features by which fluids can migrate preferentially. In this series of events we isolate two separate phases of movement. The first phase of movement being has a component of shear in which the edges of the fractures are not moving directly apart. This event is accompanied by a fluid flow event the emplaced iron oxide in the fractures and the surrounding formation. The second event is a phase when the faults become reactivated by a stress that created open mode fractures. This second is accompanied by a fluid flow event that has high calcium content and emplaces calcite in the fractures. Throughout this study we give evidence to support this series of movement and fluid events.

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Richey, David J. "Fault Seal Analysis for CO2 Storage: Fault Zone Architecture, Fault Permeability, and Fluid Migration Pathways in Exposed Analogs in Southeastern Utah." DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/6060.

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Geologic storage of anthropogenic carbon dioxide (CO2) by injection into underground porous sandstone reservoirs has been proposed as a method for the reduction of anthropogenic greenhouse gas emissions. Upwards migration and leakage of injected fluids along natural fault and fracture networks is a key risk factor for potential injection locations. We examine exposed natural analogs to evaluate the impacts of faulting and fracturing on reservoir and top-seal pairs and to evaluate evidence for paleomigration of fluids along the fault zone. We examine the Iron Wash fault, a 25-km long normal fault which cuts Jurassic sedimentary rocks and has throws that range from 20-120 m, to examine how a fault may affect seal integrity. Field mapping, kinematic analysis, petrographic analysis, characterization of the fault zone facies and fault architecture, analysis of altered and mineralized rocks in and around the fault zone, and modeling of fault seal capacity was conducted to provide an understanding of the Iron Wash fault zone. Field data and observations were combined with well log and borehole data to produce three types of models for the Iron Wash fault: 1) geometric model of the fault in the subsurface, 2) predictive models of fault zone behavior and fault seal analysis, and 3) predictive geomechanical models of the response of the fault zone to an imposed stress field and increasing the effective stress on the fault. We conclude that the Iron Wash fault zone has low sealing capacity and will likely not behave as a seal for fluids against the fault zone due primarily to modest throw on the fault and high frequency of fractures associated with the fault zone. Analysis of fluid alteration and mineralization around the fault zone indicates that the fault zone was conduit for paleo-fluids. We conclude that the fault is not likely to develop a sealing membrane and therefore will most likely fail as a seal to fluids moving through the reservoirs modeled here. Modeling results indicate that a reduction in the effective normal stress on fault surfaces may induce failure of faults resulting in earthquakes or increased hydraulic conductivity of fractures.

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Clayton, Leslie Noël. "Analysis of Small Faults in a Sandstone Reservoir Analog, San Rafael Desert: Implications for Fluid Flow at the Reservoir-Scale." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7438.

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We examined small-displacement faults in the Jurassic Entrada Sandstone adjacent to the Iron Wash Fault, central Utah east of the San Rafael Swell, in order to describe the nature and timing of past fluid movement and deformation in the Entrada Sandstone. Using field studies, microscopy, and X-ray diffraction analysis, we identified mineralized fractures and cementation features in association with deformation bands and fractures at the interface of the Earthy and Slick Rock Members of the Entrada Sandstone. Where the faults cross the Earthy-Slick Rock Member interface, deformation band faults in the Slick Rock Member become opening-mode fractures in the Earthy Member. These fractures are frequently mineralized with calcite, and goethite pseudomorphs after pyrite, providing evidence of at least two phases of fluid flow from the Entrada reservoir into the caprock in connection with deformation bands. We also observe mineralized fractures, poikilotopic cementation, and spherical to elongate concretions on and within deformation band fins in the Slick Rock Member. These features indicate the presence and movement of fluids parallel to and between deformation band fins. At some sites, deformation band faults and fractures cross and offset the interface; at others, they are present in both units, but deformation band faults do not cross the interface and fractures are not directly connected to any bands. Mineralized fractures are only found at breached-interface sites; evidence for fluid flow in the Slick Rock Member is only found in deformation band fins. Interface crossing and fracture formation is not related to proximity to the Iron Wash Fault. We propose that mesoscale faults can act as seal bypass systems and allow fluid leakage from reservoir rock into overlying less permeable rocks. Deformation bands act as both conduits for and barriers to flow, seen most clearly in deformation band fins where iron staining and mineralization is constrained between sets of bands within the fin. In CO2 or wastewater injection scenarios, interface deformation may prevent successful fluid trapping and cause re-emission of injected fluids.

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Helvey, Jacob. "Experimental Investigation of Wall Shear Stress Modifications due to Turbulent Flow over an Ablative Thermal Protection System Analog Surface." UKnowledge, 2015. http://uknowledge.uky.edu/me_etds/57.

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Modifications were made to the turbulent channel flow facility to allow for fully developed rough quasi-2D Poiseuille flow with flow injection through one surface and flow suction through the opposing surface. The combination of roughness and flow injection is designed to be analogous to the flow field over a thermal protection system which produces ablative pyrolysis gases during ablation. It was found that the additional momentum through the surface acted to reduce skin friction to a point below smooth-wall behavior. This effect was less significant with increasing Reynolds number. It was also found that the momentum injection modified the wake region of the flow.

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Arndt, Max Verfasser], Janos [Akademischer Betreuer] [Urai, Christoph [Akademischer Betreuer] Hilgers, and Stephen F. [Akademischer Betreuer] Cox. "On microstructures, fluid pathways and sealing of fractures in exhumed carbonate reservoir outcrop analogues in the Oman Mountains / Max Arndt ; János Urai, Christoph Hilgers, Stephen F. Cox." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130352374/34.

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Arndt, Max [Verfasser], Janos [Akademischer Betreuer] Urai, Christoph [Akademischer Betreuer] Hilgers, and Stephen F. [Akademischer Betreuer] Cox. "On microstructures, fluid pathways and sealing of fractures in exhumed carbonate reservoir outcrop analogues in the Oman Mountains / Max Arndt ; János Urai, Christoph Hilgers, Stephen F. Cox." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130352374/34.

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Vandromme, Rosalie. "Approche des mécanismes de l'injection sableuse per descensum." Phd thesis, École Nationale Supérieure des Mines de Paris, 2007. http://pastel.archives-ouvertes.fr/pastel-00002979.

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Les affleurements de Bevons, Nyons et Rosans dans le Sud-Est de la France, comme ceux du Numidien (Sicile, Tunisie, Maroc...) ou de la Tourelle (Canada) permettent l'observation de nombreuses injectites sableuses alimentées par des chenaux turbiditiques. Deux types d'injectites sont présents : les sills (horizontaux) et les dykes (verticaux), les dykes étant issus des sills. Leurs processus de mise en place sont, selon les auteurs, per ascensum, post-dépositionnels, et (sans doute le plus souvent) per descensum, contemporains de la mise en place du sable nourricier et objet de la présente étude. L'approche des mécanismes intervenant dans cette fracturation et la modélisation de celle-ci ont notamment pour but de préciser l'évolution de l'étanchéité des matériaux argileux pouvant constituer un site de stockage de déchets. D'un autre point de vue, des injections sableuses étant localisées entre des réservoirs contenant des hydrocarbures, une détermination de leur géométrie est nécessaire pour prédire les circulations potentielles de fluides durant la production. Un modèle géométrique a été établi à partir de ces observations et a permis de faire certaines hypothèses sur les mécanismes à prendre en compte dans les modélisations de cette fracturation et/ou injection. Plusieurs approches sont menées en parallèle : - L'étude de la compaction dans le massif, avant l'injection : pour des concentrations en sable assez élevées (> 35 %), le poids de la colonne de mélange d'injection est supérieure à la contrainte verticale dans la partie superficielle du massif. Cette inversion de densité peut être responsable du fait que l'injection se propage plutôt vers le bas dans le cas des dykes ou le long de discontinuités stratigraphiques (telles que les niveaux de cendres par exemple). Lorsque l'on descend dans les sédiments, la pression dans la colonne de mélange sableux varie linéairement avec la profondeur alors que la contrainte dans les sédiments varie non linéairement (issue d'une courbe de porosité en exponentielle). A partir d'une certaine profondeur, la pression fluide devient inférieure aux contraintes dans la succession sédimentaire : l'injection ne peut pas dépasser cette profondeur. Ainsi, la propagation des dykes est limitée par le poids de son encaissant. - L'utilisation de la fracturation hydraulique comme mécanisme de l'injection : la mécanique des roches et plus précisément les mécanismes d'hydrofracturation ont été testés pour tenter de modéliser ces observations à grande échelle. La force responsable de l'initiation et de la propagation des fractures est la pression due à la mise en place du chenal turbiditique. Le modèle tient compte du fait que l'injection doit soulever les terrains sus-jacents. Les premiers résultats ont permis de montrer que dès qu'une fracture horizontale est initiée, la propagation est rapide. L'ouverture obtenue (épaisseur d'un sill) est décamétrique, soit du même ordre de grandeur que les observations de terrain. - L'utilisation d'un fluide à seuil dans un réseau établi, avec des probabilités cohérentes avec la réalité des phénomènes entrant en jeu, a permis de déterminer les extensions maximales d'injection en accord avec les observations de terrain : - Un sill seul peut se propager sur 2400 m en quelques dizaines d'heures, - Un dyke seul peut descendre jusqu'à 400 m sous le paléofond de mer en quelques secondes, - Un réseau de sills et de dykes connectés (ce réseau étant connecté au chenal par un sill) peut avoir une extension horizontale de 1200 m et verticalement de 400 m, et se mettre en place en quelques heures. La formation des sills est plus longue que celle des dykes, la formation d'un sill seul dure plusieurs heures alors que celle d'un dyke dure quelques secondes. Lorsque les sills et les dykes sont connectés, le temps de propagation du réseau est d'environ 2 heures. Les dykes se forment toujours en quelques secondes et ont un effet sur la propagation des sills qui se propagent deux fois moins loin que s'ils étaient seuls.

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33

Lafarge, Denis. "Propagation du son dans les matériaux poreux à structure rigide saturés par un fluide viscothermique : définition de paramètres géométriques, analogie électromagnétique, temps de relaxation." Le Mans, 1993. http://cyberdoc.univ-lemans.fr/theses/1993/1993LEMA1009.pdf.

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Dans un contexte d'acoustique aérien, le rôle des longueurs caractéristiques A, A', est mis en évidence lors de mesures d'impédance, pour divers matériaux poreux absorbat)ts tels que mousses réticulées de polyurethane ou laines de verre. Au delà, une réflexion est menée concernant la notion de paramètre géométrique, la symétrie entre effets visqueux et thermiques, le rôle des temps de relaxation visqueux et thermiques. On utilise une analogie électromagnétique pour préciser la position du problème. On montre la relation entre les divers ordres d'approximation et les moments successifs de la distribution des temps de relaxation. Ceci fait apparaître la "théorie universelle" comme l'ordre 0 d'approximation. Finalement, les effets de déviation par rapport à celle-ci sont abordés
The important role played by the characteristic lengths A, A' , is demonstrated by impedance measurements, for different materials such as reticulated polyurethane foams, and glass wool. There follows a discussion of the very definition of the geometrical parameters, the symmetry between viscous and thermal effects, and the viscous and thermal relaxation times. An electromagnetic analogy is used, in order to characterize the physical definition of the problem. A connection between the various degrees of approximation and the successive moments of the relaxation times distributions is demonstrated. As a result, the so-called "universality" appears as being nothing but the approximation of degree 0. Finally, departures from the universality theory are briefly investigated

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Perdigou, Claude. "Stabilité des nappes visqueuses en écoulement ouvert." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066136/document.

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Nous étudions un rideau visqueux en écoulement vertical. Un injecteur situé en haut du domaine forme un écoulement ouvert composé d'un liquide visqueux homogène qui s'écoule dans un bain et est accéléré dans son mouvement vertical par l'effet de la gravité. Des zones présentant des taux de contrainte compressifs peuvent apparaître au sein de l'écoulement. Le rideau visqueux est alors susceptible de flamber, perdant sa géométrie plane. Le flambage d'une structure fine et visqueuse a précédemment été étudié dans le contexte d'un écoulement de base présentant une direction d'invariance, ici l'état précontraint est purement bidimensionnel. La modélisation théorique de l'écoulement ouvert prend en compte les effets advectifs. Nous introduirons des outils théoriques et numériques que nous appliquons à un problème classique de la mécanique des solides. Nous utilisons ensuite ces mêmes méthodes pour le rideau tombant. Nous obtenons un modèle de plaque visqueuse dont la cinématique mélange des vitesses et un déplacement hors plan. Les termes membranaires sont inspirés de la mécanique des structures fines et obtenus par l'analogie Stokes-Rayleigh, qui transpose aux écoulements visqueux les notions d'étirement et de flexion d'une plaque. Les équations d'équilibre de flambage étant d'ordre élevé, nous aurons recours à une implémentation numérique particulière. Les effets de la capillarité peuvent être pris en compte dans le modèle et seront étudiés. Nous concluons par une approche théorique de la stabilité de l'écoulement. Nous adaptons une méthode d'analyse des écoulements ouverts instables en cisaillement à l'équilibre de flambage du rideau visqueux
We consider a vertical sheet made up of an homogeneous viscous fluid and falling into a bath. This curtain is formed by an inlet injecting viscous fluid at the top of the domain and creating an open flow. The resulting thin structure is falling under the effect of gravity, and develops regions of compressive stress. These may lead to a mechanical instability as the sheet can buckle under compression, losing its planar geometry and deforming in the out-of-plane direction.In previous studies, buckling of a viscous sheet that leads to surface wrinkles was associated with flows having a direction of invariance. We will be considering a genuinely two-dimensional stress state.We first introduce stability methods on a simple solid mechanics problem, obtaining equations in weak form and using a finite elements solver to obtain its buckled configurations.We will then study both the modelling of the falling curtain as a viscous membrane and its numerical resolution. We will derive a model with kinematics mixing velocities and displacements and use a viscous membrane model. Inspired by the solid mechanics of thin structures it uses the Stokes-Rayleigh analogy to transpose the concepts of stretching and bending stress to viscous flows. Equations for the out-of-plane equilibrium are of high order and require a specific numerical scheme. Capillary effects can be taken into account in the model and we assess their influence.We finally present a stability analysis hoping to improve our analytical understanding of the buckling phenomenon. We adapt a framework developed for the study of open shear flows instabilities to the out-of-plane equilibrium equations

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Mohamad-Alderf, Nisrine. "Prédiction numérique des aspects instationnaires du surenfoncement dynamique d'un navire dans des chenaux fortement confinés." Compiègne, 2010. http://www.theses.fr/2010COMP1854.

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Nous nous intéressons à la modélisation numérique par éléments finis du phénomène de surenfoncement dynamique des navires. Il est proposé une chaîne de traitement numérique modulaire et donc interchangeable. Celle-ci permet d'étudier l'interaction entre m écoulement bidimensionnel à fond variable et à surface libre. Ce modèle est validé par m modèle malique d'équilibre dynamique basé sur l'extension de la théorie de Schijf (1949) aux effets dynamiques. L'intégration des contributions dynamiques du surenfoncement nous a permis de mettre en cause les critères de stabilité définis par les approches actuelles
We present a numerical model for dynamic phenomenon of squat by finite elements analysis. Lt proposes a set of modular and numerical tools therefore interchangeable. This model enables the study of the interaction betwen a two-dimension potential flow, in highly restricted waterways on irregular shaped bottom with stationary free surface. The proposed model has been validated by a stability model based on the extension of the one dimensional theory of Schijf (1949) to the dynamic effects. It is shown by testing into account the dynamic contributions of squat, the condition of stability given by the current approaches is not valid anymore

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36

Nowack, Kati. "About time." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17535.

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Zeit ist ein fundamentaler Aspekt menschlichen Verhaltens. Während Untersuchungen bislang meist nur auf einem der drei Hauptaspekte der Zeit: Dauer, Zeitfolge und individuelle zeitliche Orientierung fokussierten, untersucht diese Dissertation Zusammenhänge zwischen der individuellen zeitlichen Orientierung und der Zeitfolge. Zeit ist nicht direkt wahrnehmbar, sondern an kognitive Abstraktionsprozesse gebunden. Diese benötigen kognitive Ressourcen und werden kognitiven Fähigkeiten beeinflusst. Daher wurden Zusammenhänge zwischen individueller zeitlicher Orientierung und allgemeinen kognitiven Fähigkeiten ebenfalls untersucht. Studie 1 analysiert, wie verschiedene Aspekte individueller zeitlicher Orientierung korreliert sind, und diese Korrelationen von Alter und Geschlecht beeinflusst sind. Studien 2 und 3a analysieren Zusammenhänge zwischen individueller zeitlicher Orientierung und der Zeitfolge. Studie 3b untersucht mittels einer geometrischen Analogieanforderung Korrelationen zwischen individueller zeitlicher Orientierung und höheren fluiden Intelligenzleistungen. Befunde zu Zeitperspektive-Chronotyp- Relationen sowie Zeithorizont-Chronotyp-Relationen werden berichtet, ebenso Zusammenhänge zwischen Zeitperspektive, Zeithorizont und der Zeitfolge. Ausgehend von diesen und früheren Befunden wird ein kognitives Modell vorgestellt, welches alle drei Aspekte psychologischer Zeit (Zeitdauer; Zeitfolge; individuelle zeitliche Orientierung) integriert. Ferner werden als Ergebnis der Studien Zusammenhänge zwischen der Zukunftsperspektive und fluider Intelligenz sowie Chronotyp und verbaler Intelligenz berichtet. Verhaltensdaten und psychophysiologische Daten (Pupillendilation) zeigen ferner Zusammenhänge zwischen individueller zeitlicher Orientierung, analogem Denken, exekutiven Funktionen und Konfliktverarbeitung. So scheinen Zukunftsperspektive und Morgentyp eng mit Konfliktverarbeitung verbunden, der Zeithorizont hingegen eng mit inhibierenden Kontrollprozessen.
Time is a fundamental aspect of human experience. Whilst most research investigated major aspects of psychological time - time duration, time succession, individual temporal orientation - in isolation, this dissertation investigates interrelations between individual temporal orientation and time succession. Since psychological time is bound to cognitive abstraction processes that rely on cognitive resources and functions, interrelations between individual temporal orientation and cognitive capacities were also investigated. Study 1 explored how different levels of individuals’ temporal orientation may be interrelated, and how interrelations may be influenced by age and sex. Interrelations between individual temporal orientation and time succession were explored in a task predominantly requiring crystallized intelligence (Study 2) and in a semantic analogy task requiring crystallized and fluid intelligence (Study 3a). Study 3b investigated interrelations between individual temporal orientation and higher-level fluid intelligence measures by applying a geometric analogy task. Interrelations between time perspective and chronotype as well as between chronotype and temporal depth are reported. Further, both future time perspective and temporal depth are interrelated with time succession. A testable global working memory model of time perception integrating all three aspects of psychological time is proposed. Further, interrelations between individual temporal orientation and cognitive capacities are reported. Future time perspective was related to fluid intelligence, chronotype to verbal intelligence. Behavioral as well as pupillary data suggest that individual temporal orientation is related to analogical reasoning, executive functions and goal management. Whereas future time perspective and morningness appear interrelated with conflict detection, temporal depth appears interrelated with inhibitory control.

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37

Isoard, Mathieu. "Theoretical study of quantum correlations and nonlinear fluctuations in quantum gases." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP004.

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Cette thèse est dédiée à l’étude des phénomènes non-linéaires dans deux fluides quantiques qui partagent de nombreuses similitudes : les condensats de Bose-Einstein et les “fluides de lumière”. Dans une première partie, nous étudions les analogues soniques des trous noirs. Il est possible de créer une configuration stationnaire d’un condensat de Bose-Einstein en écoulement d’une région subsonique vers une région supersonique. Ce fluide transsonique joue alors le rôle d’un trou noir puisque les ondes sonores ne peuvent s’échapper de la région supersonique. En outre, en quantifiant le champ sonore, il est possible de montrer qu’un rayonnement de Hawking analogue émerge des fluctuations quantiques du vide. Dans cette thèse, nous montrons que la prise en compte des “modes zéros” – omis jusqu’alors dans le contexte de la gravité analogue – est essentielle pour obtenir une description précise du processus de Hawking, menant alors à un excellent accord avec les résultats expérimentaux. Enfin, nous étudions l’intrication entre les différentes excitations quantiques et montrons que notre système crée de l’intrication tripartite. Dans un second temps, nous étudions la propagation des fluides non-linéaires grâce à une approche hydrodynamique et à des méthodes mathématiques développées par Riemann et Whitham. Nous étudions la structure oscillante et la dynamique des ondes de chocs dispersives qui se forment à la suite d’un déferlement. Notre approche permet de trouver des expressions analytiques simples qui décrivent les propriétés asymptotiques du choc. Cela donne accès à des paramètres d’intérêt expérimental, comme le temps de déferlement, la vitesse de l’onde de choc ou encore le contraste de ses franges
This thesis is dedicated to the study of nonlinear-driven phenomena in two quantum gases which bear important similarities: Bose-Einstein condensates of ultracold atomic vapors and “fluids of light”. In a first part, we study sonic analogues of black holes. In a Bose-Einstein condensate, it is possible to implement a stationary configuration with a current flowing from a subsonic region to a supersonic one. This mimics a black hole, since sonic excitations cannot escape the supersonic region. Besides, quantizing the phonon field leads to a sonic analogue of Hawking radiation. In this thesis, we show that a correct account of “zero modes” – overlooked so far in the context of analogue gravity – is essential for an accurate description of the Hawking process, and results in a excellent comparison with recent experimental data. In addition, we characterize the entanglement shared among quantum excitations and show that they exhibit tripartite entanglement. In a second part, we investigate the short and long time propagation of nonlinear fluids within a hydrodynamic framework and by means of mathematical methods developed by Riemann and Whitham. In particular, we study the oscillating structure and the dynamics of dispersive shock waves which arise after a wave breaking event. We obtain a weak shock theory, from which we can extract a quantitative description of experimentally relevant parameters, such as the wave breaking time, the velocity of the solitonic edge of the shock or the contrast of its fringes

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38

Zanella, Alain. "Surpression de fluides et fracturation de roches mères en différents contextes tectoniques : modélisation analogique et exemples de terrain." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00980281.

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L'étude des surpressions de fluide et de fracturation hydraulique des roches mères peut nous renseigner sur les mécanismes de génération qui en sont à l'origine. Ces dernières années, l'intérêt pour ces phénomènes s'est largement accru, notamment sous l'influence des sociétés pétrolières qui exploitent les ressources non-conventionnelles au cœur des problèmes énergétiques actuels. Dans ce travail de thèse, nous avons choisi deux approches différentes pour l'étude de ces mécanismes : (1) des exemples de cas géologiques naturels, et (2) le développement de la modélisation analogique. Ainsi, nous montrons que ces phénomènes sont très répandus au sein des bassins sédimentaires et que leurs manifestations s'expriment notamment par la génération de veines fibreuses parallèles à la stratification de la roche (beef), mais également par la formation de veines d'hydrocarbures solides (bitume). Nous démontrons également que les surpressions de fluides peuvent profondément changer le style de déformation d'un bassin sédimentaire par la génération de niveaux de décollement localisés au sein même des roches mères. Enfin, à l'aide de la modélisation analogique, nous avons pu identifier les mécanismes à l'origine des surpressions de fluide et de la fracturation hydraulique. En effet, lors de la génération d'hydrocarbures la transformation de solide à liquide de la matière organique conduit à la compaction chimique des sédiments. Par un mécanisme de transfert de charge lors de ce processus, ainsi que par l'accroissement de volume associé, des surpressions de fluides se développent et atteignent des pressions lithostatiques, capables de fracturer hydrauliquement les roches.

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39

Bayraktar, Songul. "Theoretical And Experimental Investigation On Centrifugal Fan With A Special Interest On Fan Noise." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12608097/index.pdf.

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In this study, the effects of design parameters on the fan noise level are investigated both theoretically and experimentally. For the theoretical study, a computational aero- acoustic method is used to predict the flow induced noise of a fan. This method involves the coupling of a flow solver and a wave equation solver. Unsteady flow analysis is performed with URANS using FLUENT. Then the time dependent data are processed with LMS Sysnoise to compute the acoustic radiation. Experimental studies are performed to verify the theoretical results and additionally to investigate the effects of different design alternatives on noise level of the fan. The sound pressure and intensity level measurements are performed in the full anechoic room of Arç
elik A.S. Research and Development Laboratories. The validation experiments indicate that there is a good agreement between numerical and experimental results. The experimental study with different fan designs gives information about the noise reduction possibilities.

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Le, Merrer Marie. "Dissipation aux interfaces : caléfaction, sillages, filaments visqueux." Phd thesis, Ecole Polytechnique X, 2010. http://pastel.archives-ouvertes.fr/pastel-00537896.

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Au travers de plusieurs expériences, nous explorons le lien entre dissipation et mouvement d'interfaces liquides. Dans une première partie, nous étudions le mouvement de gouttes en caléfaction sur différents substrats. Ce mouvement peut être accéléré, si le substrat est asymétrique, ou ralenti, s'il est symétrique. La décélération des gouttes nous permet alors d'étudier différents types de friction spéciale. Sur un solide lisse, celle-ci est très faible et essentiellement due à l'air environnant. Sur un solide crénelé, elle est due à l'impact du liquide sur les marches. Enfin, si la goutte glisse sur un autre liquide, elle ralentit à cause de la résistance de vague qui résulte du sillage qu'elle engendre. La seconde partie de ce travail porte sur les déformations de filaments visqueux. Si ceux-ci sont comprimés ou tordus, nous mettons en évidence plusieurs phénomènes de flambage visqueux, que nous comparons à leurs analogues élastiques. Enfin, si les filaments sont libres de se déformer, leur forme et leur dynamique découlent d'une compétition entre viscosité, gravité et effets capillaires.

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Pons, Adeline. "Surpressions de fluide et stabilité des prismes d'accrétion : théorie et validation numérique et expérimentale." Phd thesis, Université Paris-Diderot - Paris VII, 2012. http://tel.archives-ouvertes.fr/tel-00743957.

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L'objet de cette thèse est l'étude de l'effet des surpressions de fluide sur la stabilité globale des prismes d'accrétion ainsi que sur la localisation des failles. Dans cette optique, une méthodologie utilisant le calcul à la rupture avec prise en compte de l'effet des pressions de pore ainsi qu'une approche expérimentale utilisant de l'air comprimé comme fluide interstitiel ont été mises en place. Tout d'abord, du point de vue expérimental, le nouveau protocole élaboré a permis de valider la théorie classique du prisme critique en présence de surpressions de fluide. Ensuite, le calcul à la rupture ainsi développé a permis de montrer, pour un prisme triangulaire, la complexité que peut engendrer une hétérogénéité de propriété simple dans le décollement sur la stabilité globale et sur les mécanismes de ruine mis en jeu. D'autre part, cette thèse a permis de déterminer, pour deux prismes réels (Barbades et Nankai), des champs de pression pouvant conduire à l'activation des structures observées et de proposer des scénarios expliquant la désactivation de la splay fault dans le cas de Nankai.

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Gressier, Jean-Baptiste. "Sills en milieu poreux : rôle des pressions de fluides, de la rhéologie et des échanges chimiques magma-sédiments." Le Mans, 2010. http://cyberdoc.univ-lemans.fr/theses/2010/2010LEMA1033.pdf.

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Dans la croûte supérieure, fragile, le fort contraste de rhéologie (viscosité) entre le magma et l’encaissant favorise la mise en place d’intrusions magmatiques planaires par fracturation hydraulique. Ce mode de mise en place des magmas conduit à la formation de deux types d’intrusions planaires: les dykes, subverticaux, et les sills, subhorizontaux. Nous nous sommes intéressés à deux problématiques liées à l’injection de sills en milieu poreux : (1) la profondeur de la transition dyke-sill, et (2) les conséquences mécaniques et chimiques de l’injection d’un sill dans un sédiment plastique. Dans le premier cas, nous nous sommes focalisés sur le rôle joué par les fluides sous pression présents dans la porosité de nombreuses formations sédimentaires. Grace à un nouveau protocole de modélisation analogique, nous avons montré que l’effet des pressions de fluide sur les contraintes dépend de la distribution des surpressions, et que les surpressions de fluide aux pores sont un des paramètres contrôlant la transition dyke-sill. Dans le deuxième cas, pour quantifier les échanges chimiques entre sill et encaissant, nous avons étudié les évolutions chimiques du magma et des sédiments de part et d’autre des épontes d’un sill. Nous avons ainsi mis en évidence un dégazage limité de CO2 et un enrichissement (relatif) en Terres Rares des zones altérées par la circulation de fluides. Enfin, à l’aide d’une modélisation numérique, nous avons contraint l’importance de la part plastique dans la déformation d’un encaissant sédimentaire, lors de la mise en place d’un sill. Nous avons montré une déformation plastique très localisée qui se révèle plus importante dans le cas de sills segmentés
In the upper crust, the high contrast of rheology (viscosity) between magma and host rocks favors the development of planar magmatic intrusions by hydraulic fracturing. This mode of magma setup led to the formation of two types of planar intrusions: dykes, subvertical, and sills, subhorizontal. We focused on two issues related to the injection of sills in porous media: (1) the depth of the dyke-sill transition, and (2) Mechanical and chemical consequences of the injection of a sill in a plastic sediment. In the first case, we focused on the role of fluid pressure present in the porosity of many sedimentary formations. Thanks to a new protocol for analog modeling, we have shown that the effect of fluid pressures on the constraints depends on the distribution of overpressure, and overpressure of the pore fluid is a parameter controlling the dyke-sill transition. In the second case, to quantify the chemical exchanges between sill and host rocks, we studied the chemical evolution of magma and sediment from both sides of the walls of a sill. We have identified a limited outgassing of CO2 and an enrichment (relative) in rare earth elements, in areas affected by the circulation of fluids. Finally, using numerical modeling, we have shown the importance of plasticity in deformation of a sedimentary host rock at the emplacement of a sill. We showed a highly localized plastic deformation which is more important in the case of segmented sills

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Papaxanthos, Nicolas. "Prédiction par méthode intégrale du bruit d'écoulement à faible nombre de Mach en conduite en présence d'obstacles." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2321/document.

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Ce manuscrit porte sur le développement d’une méthode de calcul du bruit d’écoulement à faible nombre de Mach en conduite en présence d’obstacles. Elle consiste en une simulation numérique de l’écoulement dont les données sauvegardées servent dans un deuxième temps à l’estimation du rayonnement acoustique. Le calcul de mécanique des fluides est réalisé avec un modèle de turbulence LES incompressible. Un code a été développé pour le calcul acoustique qui comprend la transformée de Fourier des données de l’écoulement, le calcul par méthode intégrale et les post-traitements. L’originalité de la méthode réside dans le fait qu’elle nécessite comme informations sur l’écoulement uniquement des données surfaciques. Aucune donnée volumique n’a besoin d’être sauvegardée durant le calcul de mécanique des fluides. Dans une conduite obstruée par un obstacle, les principales sources de bruit se situent à proximité de l’obstacle et le rayonnement diffracté sur l’obstacle domine sur le rayonnement direct des sources. C’est la diffraction du rayonnement incident qui rend négligeable les données volumiques dans le calcul acoustique. Elle est étudiée et illustrée à travers le cas simplifié du rayonnement d’une source placée à proximité d’un obstacle en conduite. Des comparaisons calculs/essais favorables valident la méthode et le code de calcul développé. Plusieurs configurations sont étudiées : l’insertion dans un conduit rectangulaire droit d’un diaphragme, d’un agencement de deux diaphragmes et d’un volet. En présence d’un diaphragme, une théorie de la similitude est introduite ; en présence d’un double diaphragme, des phénomènes d’interaction entre les deux obstacles apparaissent et sont analysés ; et en présence d’un volet, des résonances particulières sont examinées
This manuscript deals with the development of a calculation method of low Mach number flow noise in ducts in the presence of fixed obstacles. lt consists of a numerical simulation of the flow during which data are saved and used in a second time to estimate the acoustic radiation. The fluid calculation is performed with an incompressible LES turbulence model. A code has been developed for the acoustic computation which includes the Fourier transform of the flow data, the integral computation and the post-processing. The originality of the method lies in the fact that it requires as information on the flow only surface data. No volume term needs to be saved during the fluid calculation. ln a duct obstructed by an obstacle, the main sources of noise are located near the obstacle and the scattered field on the obstacle dominates on the direct radiation of the sources. lt is the diffraction of the incident radiation which makes the volume data negligible in the acoustic calculation. This is studied and illustrated through the simplified case of the radiation from a source located near a ducted obstacle. Favorable comparisons with measurements validate the method and the developed code. Several configurations are studied: the insertion into a straight rectangular duct of a diaphragm, an arrangement of two diaphragms and a flap. ln the presence of a diaphragm, a theory of similarity is introduced; in the presence of a double diaphragm, interaction phenomena between the two obstacles appear and are analyzed; and in the presence of a flap, particular resonances are examined

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Golanski, François. "Méthode hybride pour le calcul du rayonnement acoustique d'écoulements anisothermes à faibles nombres de Mach." Phd thesis, Université de Poitiers, 2004. http://tel.archives-ouvertes.fr/tel-00008585.

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Cette étude propose une approche aéroacoustique hybride pour le calcul du bruit rayonné par des écoulements subsoniques turbulents anisothermes. La partie aérodynamique est obtenue à l'aide d'une simulation numérique directe des équations de Navier-Stokes dans une approximation à faible nombre de Mach. Cette formulation permet de se libérer des effets de la compressibilité - numériquement pénalisants - tout en préservant l'influence des phénomènes relatifs à la dilatation thermique sur l'écoulement. La propagation acoustique est calculée par la résolution des équations d'Euler linéarisées. La définition rigoureuse des sources acoustiques constitue le lien entre ces deux étapes. Des sources spécifiques aux écoulements anisothermes, compatibles avec celles déjà connues pour les écoulements isothermes, sont obtenues. Cette approche est d'abord validée pour des couches de mélange isothermes et anisothermes par comparaison à des calculs directs. D'autres validations sont réalisées pour une couche de mélange isotherme spatiale et confrontés à des résultats de la littérature. Les contributions au bruit des différents termes sources sont examinées pour une couche de mélange spatiale anisotherme. L'évolution du rayonnement acoustique en fonction du rapport de températures est étudié pour une couche de mélange temporelle. Les résolutions numériques reposent sur une discrétisation spatiale par des schémas aux différences finies d'ordres élevés (schémas compacts) et des schémas d'intégration en temps de Runge-Kutta. Ces schémas d'ordres élevés, et les conditions aux limites performantes respectent les exigences numériques spécifiques à l'aéroacoustique.

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Jebelli, Ali. "Development of Sensors and Microcontrollers for Underwater Robots." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31283.

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Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.

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Walte, Nicolas Peter [Verfasser]. "The grain-scale distribution and behaviour of melt and fluid in crystalline analogue systems / Nicolas Peter Walte." 2005. http://d-nb.info/975927353/34.

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Costa, Diana Raquel Carvalho da. "Study of blood cells flowing in microchannels with diverging bifurcations and development of an innovative blood analogue fluid." Master's thesis, 2018. http://hdl.handle.net/1822/70733.

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Dissertação de mestrado em Biomedical Engineering
Blood is a non-Newtonian fluid made up of different types of cells, platelets and a yellowish liquid called plasma and it is essential for the diagnosis of various diseases. Blood flow is a topic of great interest to the scientific community and therefore several studies have been done using microfluidic devices to mimic the microvascular system. As the experiments with real blood are often complex due to safety, economical and bureaucratic issues, the research about the development of blood-like fluids has been during the years an important research topic. In the first phase of this work, a blood analog was developed using the Encapsulator B-395 Pro and alginate to produce flexible microparticles to mimic the red blood cells (RBCs). To reach the goal, different procedures were tested. Overall, the results were satisfactory. In a second phase, microchannels in polydimethylsiloxane (PDMS) were manufactured using a soft lithography technique. The master molds in SU-8 were manufactured by photolithography and well-defined complex structures were obtained. These microchannel networks aimed to study the flow behavior of individual RBCs at diverging bifurcations. Finally, individual RBCs were studied in microchannels having diverging bifurcations with different angles. The deformation and velocity of RBCs were measured by using a high-speed video microscopy system. Overall, the results clearly indicate that the stagnation region located at the bifurcation apex strongly influence both RBCs velocity and deformability. Additionally, around the apex the cells in addition to the increase of the deformation also seem to suffer a rotational motion. This work provides an important contribution to the field of blood analogues, microfluidics and microcirculation.
O sangue é um fluido não newtoniano constituído por diferentes tipos de células, plaquetas e um líquido amarelado chamado plasma e é essencial para o diagnóstico de várias doenças. O escoamento sanguíneo é um tema de grande interesse para a comunidade científica e por isso vários estudos têm sido feitos recorrendo a dispositivos microfluídicos para imitar o sistema microvascular. Como os experimentos com sangue são frequentemente complexos devido a questões de segurança, económicas e burocráticas, a investigação sobre o desenvolvimento de fluidos análogos ao sangue tem sido, durante anos, alvo de investigação. Numa primeira fase deste trabalho, foi desenvolvido um análogo ao sangue recorrendo ao equipamento Encapsulator B-395 Pro e ao Alginato para fabricar micropartículas a imitar os glóbulos vermelhos. Para se atingir o objetivo testaram-se diferentes procedimentos. De uma forma geral os resultados foram satisfatórios. Numa segunda fase foram fabricados microcanais em polidimetilsiloxano (PDMS) recorrendo à técnica litografia suave. Os moldes master em SU-8 foram fabricados por fotolitografia e obtiveram-se estruturas bem definidas. Estes microcanais tinham como objetivo o estudo do comportamento do escoamento de glóbulos vermelhos individuais em bifurcações divergentes. Por último, os glóbulos vermelhos foram estudados individualmente em microcanais que continham bifurcações divergentes com diferentes ângulos. Mediu-se a deformação e velocidade dos glóbulos vermelhos recorrendo a uma câmara de alta velocidade e a um microscópio. No geral, os resultados indicam claramente que a região de estagnação localizada no ápex da bifurcação influencia fortemente a velocidade e deformação dos glóbulos vermelhos. Além disso, em torno do ápex, as células, além do aumento da deformação, também parecem sofrer um movimento de rotação. Este trabalho fornece uma importante contribuição para a área dos fluidos análogos ao sangue, microfluídica e microcirculação.

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Babb, James Patrick. "The derivation and quasinormal mode spectrum of acoustic anti-de sitter black hole analogues." Thesis, 2013. http://hdl.handle.net/1828/4484.

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Dumb holes (also known as acoustic black holes) are fluid flows which include an "acoustic horizon:" a surface, analogous to a gravitational horizon, beyond which sound may pass but never classically return. Soundwaves in these flows will therefore experience "effective geometries" which are identical to black hole spacetimes up to a conformal factor. By adjusting the parameters of the fluid flow, it is possible to create an effective geometry which is conformal to the Anti-de Sitter black hole spacetime- a geometry which has recieved a great deal of attention in recent years due to its conjectured holographic duality to Conformal Field Theories. While we would not expect an acoustic analogue of the AdS-CFT correspondence to exist, this dumb hole provides a means, at least in principle, of experimentally testing the theoretical properties of the AdS spacetime. In particular, I have calculated the quasinormal mode spectrum of this acoustic geometry.
Graduate
0986
0753
jpbabb@yahoo.ca

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Wang, Zhen. "Body Fluid Analogues and Personal Care Products as Potential DBP Precursors." Thesis, 2011. http://hdl.handle.net/1807/29637.

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Disinfection byproducts (DBPs), such as organic chloramines, THMs, HAAs, and nitrosamines, are formed during mandatory disinfection processes in drinking water treatment. Many of these DBPs have been shown to be potentially carcinogenic. Extensive research has been conducted on the occurrence and formation of these DBPs. However, there has been limited research on their relationships with each other, which may be important for the understanding of their formation mechanisms, and the nature of their precursors is still relatively unknown. Ultimately, this information will be key for the development of possible improvements in treatment technologies. Results of this study improve the understanding of DBP formation in swimming pool water. Some BFAs and PCP additives were identified as potential DBP precursors. Influence of BFAs and PCP additives on DBP formation in swimming pool water was also illustrated. Results provided feasible strategies to minimize DBP formation while maintaining the efficiency of disinfection.

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Lin, Yen-Chin, and 林彥志. "The Application of Time-Dependent Fluid Analogy Method on Origin-Destination Estimation of Access-Controlled Corridors." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/13584296512388037704.

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碩士
中原大學
土木工程研究所
95
In the field of transportation planning, planners often need some origin- destination data to know about the trip distribution in the region, and then do more properly planning in modal split and traffic assignment. However, the traditional ways which obtain the O-D data usually cost a large amount of time, money, and human resources. In addition, since it could be affected by weather, artificially negligence or mechanical disorder, the O-D data we obtained might have low accuracy. Therefore, the research on the model in O-D estimation has been a continuous study topic in transportation. Due to the assignment between each O-D pair in corridor is hard to obtain, so the data set used by estimation in research are often the in-flow and out-flow counts of access ramps, and how to use these flow data to build the relationship between each O-D pair is very important in the model. This research is based on fluid analogy method proposed by Tsygalnitzky, following the research of Kuo(2005) and Lin(2006), continued to discuss the development and application of fluid analogy method on O-D estimation of access-controlled corridor. The hypothesis used in the past, including the unitary factor of relative attractiveness for all day long and the fixed distance among ramps were re-examined in this research. For the modified model in this study, the fixed factor of relative attractiveness in the time-dependent fluid analogy method varies with time, and so do the distances among ramps. According to the simulation tests, the model was able to deliver sound results in the situation of flow varying along time dimension.

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