Numerical solution of differential equations having multitude of scales in the solution field is one of the most challenging research areas, but highly demanded in scientific and industrial applications. One of the natural approaches for handling such problems is to separate the scales and approximate the solution of the segregated scales with appropriate numerical method. Variational multiscale method (VMS) is a predominant method in the paradigm of scale separation schemes. In our work we have used the VMS technique to develop a numerical scheme for computations of turbulent flows in time-dependent domains. VMS allows separation of the entire range of scales in the flow field into two or three groups, thereby enabling a different numerical treatment for the different groups. In the context of computational fluid dynamics(CFD), VMS is a significant new improvement over the classical large eddy simulation (LES). VMS does away with the commutation errors arising due to filtering in LES. Further, in a three-scale VMS approach the model for the subgrid scale can be contained to only a part of the resolved scales instead of effecting the entire range of resolved scales. The projection based VMS scheme that we have developed gives a robust and efficient method for solving problems of turbulent fluid flows in deforming domains, governed by incompressible Navier {Stokes equations. In addition to the existing challenges due to turbulence, the computational complexity of the problem increases further when the considered domain is time-dependent. In this work, we have used an arbitrary Lagrangian-Eulerian (ALE) based VMS scheme to account for the domain deformation. In the proposed scheme, the large scales are represented by an additional tensor valued space. The resolved large and small scales are computed in a single unified equation, and the effect of unresolved scales is confined only to the resolved small scales, by using a projection operator. The popular Smagorinsky eddy viscosity model is used to approximate the effects of unresolved scales. The used ALE approach consists of an elastic mesh update technique. Moreover, a computationally efficient scheme is obtained by the choice of orthogonal finite element basis function for the resolved large scales, which allows to reformulate the ALE-VMS system matrix into the standard form of the NSE system matrix. Thus, any existing Navier{Stokes solver can be utilized for this scheme, with modifications. Further, the stability and error estimates of the scheme using a linear model of the NSE are also derived. Finally, the proposed scheme has been validated by a number of numerical examples over a wide range of problems.

Este trabalho consiste no desenvolvimento de ferramentas computacionais para análise não linear geométrica de interação fluido-casca utilizando o Método dos Elementos Finitos (MEF). O algoritmo para dinâmica dos fluidos é explícito e a integração temporal é baseada em linhas características. O código computacional é capaz de simular as equações de Navier-Stokes para escoamentos compressíveis tanto na descrição Euleriana como na descrição Lagrangeana-Euleriana arbitrária (ALE), na qual é possível prescrever movimentos para a malha do fluido. A estrutura é modelada em descrição Lagrangeana total através de uma formulação de MEF para análise dinâmica não linear geométrica de cascas baseada no teorema da mínima energia potencial total escrito em função das posições nodais e vetores generalizados e não em deslocamentos e rotações. Essa característica evita o uso de aproximações de grandes rotações. Dois modelos de acoplamentos são desenvolvidos. O primeiro modelo, ideal para problemas onde a escala de deslocamentos não é muito grande comparada com as dimensões do domínio do fluido, é baseado na descrição ALE e o acoplamento entre as duas diferentes malhas é feito através do mapeamento das posições locais dos nós do contorno do fluido sobre os elementos de casca e vice-versa, evitando a necessidade de coincidência entre os nós da casca e do fluido. A malha do fluido é adaptada dinamicamente usando um procedimento simples baseado nas posições e velocidades nodais da casca. O segundo modelo de acoplamento, ideal para problemas com grande escala de deslocamentos tais como estruturas infláveis, considera a casca imersa na malha do fluido e consiste em um procedimento robusto baseado em curvas de nível da função distância assinalada do contorno, o qual integra o algoritmo Lagrangeano de casca com o Fluido em descrição Euleriana, sem necessidade de movimentação da malha do fluido, onde a representação computacional do fluido se resume a uma malha não estruturada maior ou igual ao domínio inicial do fluido e a interface fluido-casca dentro da malha do fluido é identificada por meio de curvas de nível da função distância assinalada do contorno. Ambos os modelos são testados através de exemplos numéricos mostrando robustez e eficiência. Finalmente, como uma sugestão para o futuro desenvolvimento desta pesquisa, iniciaram-se estudos relativos a funções B-splines. O uso desse tipo de funções deverá resolver problemas de estabilidade relativos a oscilações espúrias devidas ao uso de polinômios de Lagrange para a representação de descontinuidades. / This work consists of the development of computational tools for nonlinear geometric fluid-shell interaction analysis using the Finite Element Method (FEM). The fluid solver is explicit and its time integration based on characteristics. The computational code is able to simulate the Navier-Stokes equations for compressible flows written in the Eulerian description as well as in the arbitrary Lagrangian-Eulerian (ALE) description, enabling movements prescription for the fluid mesh. The structure is modeled in a total Lagrangian description, using a FEM formulation to deal with geometrical nonlinear dynamics of shells based on the minimum potential energy theorem written regarding nodal positions and generalized unconstrained vectors, not displacements and rotations, avoiding the use of large rotation approximations. Two partitioned coupling models are developed. The first model, ideal for simulations where the displacements scale is not very large compared to the fluid domain, is based on the ALE description and the coupling between the two different meshes is done by mapping the fluid boundary nodes local positions over the shell elements and vice-versa, avoiding the need for matching fluid and shell nodes. The fluid mesh is adapted using a simple approach based on shell nodal positions and velocities. The second model, ideal for problems with large scales of displacements such as inflatable structures, is based on immersed boundary and consists of a robust level-set based approach that integrates the Lagrangian shell finite and the Eulerian finite element high speed fluid flow solver, with no need for mesh adaptation, where the fluid representation relies on a fixed unstructured mesh larger or equal to the initial fluid domain and the fluid-shell interface inside the fluid mesh is tracked with level sets of a boundary signed distance function. Both models are tested with numerical examples, showing efficiency and robustness. Finally, as a suggestion for future development of this research, we started studies relatives to B-Spline functions. The use of this kind of functions should solve stability problems related to spurious oscillations due to the use of Lagrange polynomials for representing discontinuities.

Die Dynamik von elastischen Membranen, Kapseln und Schalen hat sich zu einem aktiven Forschungsgebiet in der simulationsgestützten Physik und Biologie entwickelt. Die dünne Oberfläche dieser elastischen Materialien ermöglicht es, sie effizient als Hyperfläche zu approximieren. Solche Oberflächen reagieren auf Dehnungen in Oberflächenrichtung und Verformungen in Normalenrichtung mit einer elastischen Kraft. Zusätzlich können Oberflächenspannungskräfte auftreten. In dieser Arbeit präsentieren wir eine neuartige Arbitrary Lagrangian-Eulerian (ALE) Methode um solche in (Navier-Stokes) Fluiden eingebetteten elastischen Schalen zu simulieren. Dadurch, dass das Gitter an die elastische Oberfläche angepasst ist, kombiniert die vorgeschlagene Methode hohe Genauigkeit mit Effizienz in der Berechnung der Lösungen. Folglich kann man die Simulationen mit einer verhältnismäßig geringen Gitterauflösung durchführen. Der Fokus dieser Arbeit liegt bei achsensymmetrischen Formen und Strömungen, wie sie bei vielen biophysikalischen Anwendungen zu finden sind. Neben einer allgemeinen dreidimensionalen Beschreibung formulieren wir achsensymmetrische Kräfte auf der Oberfläche, für welche wir eine Diskretisierung mit der Finite Differenzen Methode vorschlagen, welche an eine Finite-Elemente Methode für die umgebenden Fluide gekoppelt ist. Weiterhin entwickeln wir eine Strategie zur impliziten Kopplung der Kräfte, um Zeitschrittrestriktionen zu reduzieren. In verschiedenen numerischen Tests werden wir zeigen, dass akkurate Ergebnisse schon in einer Größenordnung von Minuten auf einer Single-Core CPU erreicht werden können. Die Methode wurde in drei aktuellen Anwendungen verwendet, wobei mindestens zwei davon nach unserer Kenntnis im Moment mit keiner anderen numerischen Methode simuliert werden können: Zunächst präsentieren wir Simulationen von biologischen Zellen, die im Zuge eines RT-DC (Real-Time Deformability Cytometry) Experiments durch einen schmalen mikrofluidischen Kanal advektiert und dabei verformt werden. Danach zeigen wir die Ergebnisse erster Simulationen der uniaxialen Kompression biologischer Zellen zwischen zwei parallelen Platten im Zuge eines AFM Experiments. Schließlich präsentieren wir Resultate erster Simulationen von neuartigen mikroschwimmenden Schalen, welche lediglich durch äußere Einflüsse (wie z.B. Ultraschall), zum Schwimmen angeregt werden können. / The dynamics of membranes, shells, and capsules in fluid flow has become an active research area in computational physics and computational biology. The small thickness of these elastic materials enables their efficient approximation as a hypersurface, which exhibits an elastic response to in-plane stretching and out-of-plane bending, possibly accompanied by a surface tension force. In this work, we present a novel arbitrary Lagrangian-Eulerian (ALE) method to simulate such elastic surfaces immersed in Navier-Stokes fluids. The method combines high accuracy with computational efficiency, since the grid is matched to the elastic surface and can therefore be resolved with relatively few grid points. The focus of this work is on axisymmetric shapes and flow conditions, which are present in a wide range of biophysical problems. Next to a general three-dimensional description, we formulate axisymmetric elastic surface forces and propose a discretization with surface finite-differences coupled to evolving finite elements. We further develop an implicit coupling strategy to reduce time step restrictions. Several numerical test cases show that accurate results can be achieved at computational times on the order of minutes on a single core CPU. Three state-of-the-art applications are demonstrated, where to our knowledge at least two of them cannot be simulated with any other numerical method so far. First, simulations of biological cells being advected through a microfluidic channel and therefore being deformed during an RT-DC (Real-Time Deformability Cytometry) experiment are presented. Then, the uniaxial compression of the cortex of a biological cell during an AFM experiment is investigated. Finally, we present the results of first simulations of the observed shape oscillations of novel microswimming shells which can be locomoted by exterior influences (e.g. ultrasound waves) only.

Cette thèse s'intéresse aux simulations dépendantes du temps impliquant des géometries fixes ou mobiles. Ce type de simulations est l'objet d'attentes grandissantes de la part des industriels, qui souhaiteraient voir réaliser ce type de calculs de façon systématique au sein de leurs centres de recherche, ce qui n'est clairement pas le cas à l'heure actuelle. Ce travail tente de satisfaire en partie cette demande et vise notamment à améliorer la précision ainsi que l'efficacité en termes de temps de calcul des algorithmes actuellement utilisés dans ce contexte. Les méthodes d'adaptation de maillage anisotrope par prescription d'un champ de métriques, qui ont aujourd'hui atteint une certaine maturité, notamment dans leur application aux simulations stationnaires, constituent une piste très prometteuse pour l'amélioration des calculs évoluant en temps, mais leur extension dans ce contexte est loin d'être triviale. Quant à leur utilisation sur les simulations en géométries mobiles, seules quelques tentatives peuvent être répertoriées, et très peu portent sur des problèmes réalistes en trois dimensions. Cette étude présente plusieurs nouveautés sur ces questions, notamment l'extension de l'adaptation de maillage multi-échelles par champ de métriques aux problèmes instationnaires en géométries fixes et mobiles. Par ailleurs, essentiellement dans une optique de réduction des temps de calculs, une stratégie originale à été adoptée pour réaliser des calculs impliquant des maillages mobiles. Notamment, il est démontré par la pratique dans cette thèse qu'il possible de déplacer des objets en trois dimensions sur de grandes distances en maintenant le nombre de sommets du maillage constant, c'est-à-dire en limitant les types d'opérations de modification de maillage autorisés. Il en résulte un gain conséquent en terme de temps de calcul aussi bien au niveau du déplacement de maillage qu'au niveau de la résolution numérique. Par ailleurs, un nouveau schéma est proposé qui permet de gérer les changements de connectivité du maillage de manière cohérente avec la description Arbitrary-Lagrangian-Eulerian des équations physiques. La plupart de ces nouvelles méthodes ont été appliquées à la simulation d'écoulements fluides compressibles autour de géometries complexes en deux et trois dimensions d'espace.

The thesis deals with four plays written by French dramatist and theorist of feminism Hélène Cixous for the Parisian Théâtre du Soleil under the directorial guidance of Ariane Mnouchkine. The analysis focuses on three different perspectives - firstly on écriture feminine, defined in the 1970s by Cixous herself, secondly on exile studies, a field of literary criticism concerned with the writings of exiled authors and exile as a fundamental category of human existence, and lastly on the concept of orientalism developed in the 1970s by American literary historian of Palestinian origin Edward Said.

In Operations Enduring Freedom and Iraqi Freedom, explosions accounted for 81% of all injuries; this is a higher casualty percentage than in any previous wars. Blast wave overpressure has recently been associated with varying levels of traumatic brain injury in soldiers exposed to blast loading. Presently, the injury mechanism behind primary blast brain injury is not well understood due to the complex interactions between the blast wave and the human body. Despite these limitations in the understanding of head injury thresholds, head kinematics are often used to predict the overall potential for head injury. The purpose of this study was to investigate head kinematics, and predict injury from a range of simulated blast loads at varying standoff distances and differing heights of bursts. The validated Generator of body data multi-body human surrogate model allows for numerical kinematic data simulation in explicit finite element method fluid structure interaction blast modeling. Two finite element methods were investigated to simulate blast interaction with humans, an enhanced blast uncoupled method, and an Arbitrary Lagrangian Eularian fully coupled method. The enhanced blast method defines an air blast function through the application of a blast pressure wave, including ground reflections, based on the explosives relative location to a target; the pressures curves are based on the Convention Weapons databases. LBE model is efficient for parametric numerical studies of blast interaction where the target response is the only necessary result. The ALE model, unlike classical Lagrangian methods, has a fixed finite element mesh that allows material to flow through it; this enables simulation of large deformation problems such as blast in an air medium and its subsequent interaction with structures. The ALE model should be used when research into a specific blast scenario is of interest, since this method is more computationally expensive. The ALE method can evaluate a blast scenario in more detail including: explosive detonation, blast wave development and propagation, near-field fireball effects, blast wave reflection, as well as 3D blast wave interaction, reflection and refraction with a target. Both approaches were validated against experimental blast tests performed by Defense Research and Development Valcartier and ConWep databases for peak pressure, arrival time, impulse, and curve shape. The models were in good agreement with one another and follow the experimental data trend showing an exponential reduction in peak acceleration with increasing standoff distance until the Mach stem effect reached head height. The Mach stem phenomenon is a shock front formed by the merging of the incident and reflected shock waves; it increases the applied peak pressure and duration of a blast wave thus expanding the potential head injury zone surrounding a raised explosive. The enhanced blast model was in good agreement with experimental data in the near-field, and mid-field; however, overestimated the peak acceleration, and head injury criteria values in the far-field due to an over predicted pressure impulse force. The ALE model also over predicted the response based on the head injury criteria at an increased standoff distance due to smearing of the blast wave over several finite elements leading to an increased duration loading. According to the Abbreviated Injury Scale, the models predicted a maximal level 6 injury for all explosive sizes in the near-field, with a rapid acceleration of the head over approximately 1 ms. There is a drastic exponential reduction in the insult force and potential injury received with increasing standoff distance outside of the near-field region of an explosive charge.

<p align="justify">This work deals with the development of numerical methods for compressible flow simulation with application to the interaction of fluid flows and structural bodies.</p><p><p><p align="justify">First, we develop numerical methods based on multidimensional upwind residual distribution (RD) schemes. Theoretical results for the stability and accuracy of the methods are given. Then, the RD schemes for unsteady problems are extended for computations on moving meshes. As a second approach, cell centered and vertex centered finite volume (FV) schemes are considered. The RD schemes are compared to FV schemes by means of the 1D modified equation and by the comparison of the numerical results for scalar problems and system of Euler equations. We present a number of two and three dimensional steady and unsteady test cases, illustrating properties of the numerical methods. The results are compared with the theoretical solution and experimental data.</p><p><p><p align="justify">In the second part, a numerical method for fluid-structure interaction problems is developed. The problem is divided into three distinct sub-problems: Computational Fluid Dynamics, Computational Solid Mechanics and the problem of fluid mesh movement. The problem of Computational Solid Mechanics is formulated as a system of partial differential equations for an anisotropic elastic continuum and solved by the finite element method. The mesh movement is determined using the pseudo-elastic continuum approach and solved again by the finite element method. The coupling of the problems is achieved by a simple sub-iterative approach. Capabilities of the methods are demonstrated on computations of 2D supersonic panel flutter and 3D transonic flutter of the AGARD 445.6 wing. In the first case, the results are compared with the theoretical solution and the numerical computations given in the references. In the second case the comparison with experimental data is presented.</p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Malgré l’amélioration du régime des droits de propriété intellectuelle (DPI) en Chine après l’accession de celle-ci à l’Organisation mondiale du commerce (OMC) en 2001, la question relative aux DPI demeure l’un des « sujets de vive préoccupation » dans le commerce sino-européen. Selon la stratégie européenne visant à assurer le respect des DPI dans les pays tiers, adoptée en 2005 et renouvelée en 2014, la Chine est ciblée par la Commission européenne comme le premier pays tiers dans lequel les autorités locales ne prennent pas de mesure efficace pour s’attaquer aux problèmes de violations des DPI. En raison des enjeux politiques et économiques importants pour l’UE, son intervention est nécessaire pour améliorer le régime des DPI et l’environnement de l’investissement en Chine. L’analyse de l’action extérieure de l’UE s’appuie sur l’étude des instruments auxquels elle recourt en vue de renforcer la protection et le respect des DPI en Chine. L’objet de notre recherche est d’examiner la manière dont l’Union choisit d’exploiter les instruments à géométrie variable au sein des enceintes multilatérale et bilatérale. Deux axes distincts mais complémentaires orientent la mise en œuvre de l’action extérieure de l’UE vis-à-vis de la Chine : l’approche coopérative, d’une part, et de l’approche conventionnelle, d’autre part. L’approche coopérative vise d’abord à rapprocher le régime juridique chinois des standards les plus élevés du droit de l’UE. En dépit d’un certain nombre de difficultés limitant l’efficacité de l’action extérieure de l’UE, la coopération bilatérale avec la Chine permet de contribuer à l’amélioration du régime juridique chinois. La convergence normative devrait ensuite faciliter l’apparition d’une approche commune entre l’UE et la Chine sur le plan conventionnel. Il importe à cet égard de souligner la position divergente de la Chine face à la promotion de l’UE, par la voie conventionnelle, d’un renforcement de la protection et du respect des DPI. Malgré la convergence accrue des positions européenne et chinoise favorables à la protection « ADPIC-plus » des DPI, la Chine se montre réticente voire hostile envers les initiatives conventionnelles de l’UE tendant à renforcer les mesures relatives au respect des DPI. / Despite the improvement of China’s intellectual property rights (IPR) regime after this country’s World Trade Organization (WTO) accession in 2001, the IPR remains one of “major concerns” in Sino-European trade relation. According to European strategy for the enforcement of intellectual property rights in third countries, adopted in 2005 and renewed in 2014, China is identified by the European Commission as first priority country, in which the local authority does not take effective measures to tackle the problems caused by IPR violations. Taking into account the EU’s important political and economic concerns, his action is necessary in order to improve the IPR regime and the investment environment in China. The analysis of EU’s external action is based on the instruments used to strengthen IPR’s protection and enforcement in China. The purpose of our research is to examine the EU’s method to use the different instruments within the multilateral and bilateral fora. Two distinct but complementary axes orientate the undertaking of EU’s external action vis-à-vis China: cooperative approach, on the one hand, and the conventional approach, on the other hand. Firstly, the cooperative approach aims to bring Chinese legal system closer to higher standards in EU law. In spite of certain difficulties limiting the efficacy of EU external action, the bilateral cooperation with China can contribute to a better legal system in China. Then, the normative convergence should be able to facilitate the emergence of a common approach between the EU and China in the conventional framework. In this respect, it is important to emphasis Chinese divergent position with regard to EU’s conventional approach aiming to strengthen IPR protection and enforcement. Despite the increasing convergence of European and Chinese positions favorable toward “TRIPs-plus” protection, China seems reluctant even hostile to EU’s conventional initiatives intending to strengthen IPR enforcement measures.

El objetivo de esta monografía es tratar de determinar en qué medida y de qué manera cuatro manuales didácticos suecos de español como lengua extranjera (ELE), usados en la enseñanza en el nivel de bachillerato, tratan aspectos pragmáticos. Además, evaluaremos el potencial y la relevancia de la información metapragmática y las actividades relacionadas a los aspectos pragmáticos para el proceso de adquisición de una competencia tanto metapragmática como pragmática. En este estudio se parte de la noción de la competencia pragmática como una destreza orientada a saber crear y comprender significados en la interacción de manera eficaz (Thomas, 1995), que supone, más que los conocimientos lingüísticos en una interacción intercultural, los conocimientos extralingüísticos (cf. Bravo, 2005). La hipótesis de partida de este trabajo postula que los manuales no explican a fondo por qué cierto lenguaje se utiliza en ciertos contextos y que el contenido pragmático sería poco variado y difícil de asimilar y que los ejercicios no estarían diseñados principalmente para desarrollar la competencia pragmática. Hasta cierta medida se puede decir que los resultados de esta investigación confirman la hipótesis: los manuales podrían efectivamente ser más exhaustivos en cuanto a los temas que abarcan, asimismo podrían variar y explicar más a fondo aquellos temas. No obstante, parece haber un esfuerzo de incorporar actividades comunicativas e información extralingüística, sin embargo, hace falta una conceptualización y progresión en cuanto a cómo tratar estos temas como el propósito principal. Ni siquiera se ofrecen en las guías del profesor modelos didácticos o información adicional, y por lo general, no se combina la información metapragmática en los manuales con actividades complementarias que pretenden desarrollar las destrezas comunicativas. / The purpose of this paper is to try to determine to what extent and in what way four Swedish textbooks on Spanish as a foreign language (SFL) treat pragmatic aspects, as well as to evaluate the potential and relevance of the metapragmatic information and activities related to pragmatic aspects provided by the textbooks, for the development of pragmatic awareness and competence in Spanish. This study parts from the notion of pragmatic competence as a skill of knowing how to create and understand meanings in interaction effectively (Thomas, 1995), which in intercultural interaction probably requires extra-linguistic knowledge more than language skills (cf. Bravo, 2005). The hypothesis postulated at the beginning of the study was that the manuals would not fully explain why certain language is being used in certain contexts, that the pragmatic content would be scarcely varied and rather difficult to assimilate and that the exercises would not be designed primarily to develop a pragmatic competence. To some extent it can be said that the hypothesis is confirmed: the manuals could have been more comprehensive in terms of the topics covered, they could also have varied and explained those issues further. Despite the fact that there seems to be an effort to incorporate extra-linguistic information and communicative activities, the results indicate that there is a lack of emphasis on or progression on how to treat these issues. For example, there are no didactic models or suggestions in the teacher’s guide, nor is additional information provided elsewhere; usually the metapragmatic information is not combined with any activities, and the activities that aim to develop communicative skills are not combined with further metapragmatic information.

This diploma thesis examines changes, which the Czech-German Future Fund went through during its almost 20 years of functioning. The first part the author dedicated to theoretical concepts, which shed light on study of the Czech-German Future Fund. These theoretical concepts are reconciliation and public diplomacy. Thereafter are in tis thesis described efforts to compensate victims of National Socialism in Czechoslovakia and in the Czech Republic. This part of thesis is followed by description of the Czech-German Future Fund and its history. Based on this German-Czech Declaration of Mutual Relations and their Future Development of 1997 was the fund's mission to compensate victims of National Socialism, who didn't receive a compensation until then. The fund fulfilled this mission after 10 years of its function and also went through by many changes during almost 10 years of its functioning. The author describes these changes on which is based description of the project policy development of Czech-German Future Fund. After that the diploma thesis concentrates on changes in individual fund project groups, which are supported by the fund. These changes have an impact on financial character of individual project groups, on change of their structure or on change of the place, where are individual...