Existing numerical techniques for modeling saturated deformable porous media are based on homogenization techniques and thus are incapable of performing micro-mechanical investigations, such as the effect of micro-structure on the deformational characteristics of the media. In this research work, a numerical scheme is developed based on the parallelized hybrid lattice-Boltzmann finite-element method, that is capable of performing micro-mechanical investigations through direct numerical simulations. The method has been used to simulate compression of model saturated porous media made of spheres and cylinders in regular arrangements. Through these simulations it is found that in the limit of small Reynolds number, Capillary number and strain, the deformational behaviour of a real porous media can be recovered through model porous media when the parameters porosity, permeability and bulk compressive modulus are matched between the two media. This finding motivated research in using model porous geometries to represent more complex real porous geometries in order to perform investigations of deformation on the latter. An attempt has been made to apply this technique to the complex geometries of ªfeltº, (a fibrous mat used in paper industries). These investigations lead to new understanding on the effect of fiber diameter on the bulk properties of a fibrous media and subsequently on the deformational behaviour of the media. Further the method has been used to investigate the constitutive relationships in deformable porous media. Particularly the relationship between permeability and porosity during the deformation of the media is investigated. Results show the need of geometry specific investigations.

<p>Much of the vibration in fast moving vehicles is caused bydistributed random excitation, such as turbulent flow and roadroughness. Piping systems transporting fast flowing fluid isanother example, where distributed random excitation will causeunwanted vibration. In order to reduce these vibrations andalso the noise they cause, it is important to have accurate andcomputationally efficient prediction methods available.</p><p>The aim of this thesis is to present such a method. Thefirst step towards this end was to extend an existing spectralfinite element method (SFEM) to handle excitation of planetravelling pressure waves. Once the elementary response tothese waves is known, the response to arbitrary homogeneousrandom excitation can be found.</p><p>One example of random excitation is turbulent boundary layer(TBL) excitation. From measurements a new modified Chase modelwas developed that allowed for a satisfactory prediction ofboth the measured wall pressure field and the vibrationresponse of a turbulence excited plate. In order to model morecomplicated structures, a new spectral super element method(SSEM) was formulated. It is based on a waveguide formulation,handles all kinds of boundaries and its elements are easily putinto an assembly with conventional finite elements.</p><p>Finally, the work to model fluid-structure interaction withanother wave based method is presented. Similar to the previousmethods it seems to be computationally more efficient thanconventional finite elements.</p>

In the context of interior noise reduction, the present work aims at proposing Finite Element (FE) solution strategies for interior structural-acoustic applications including 3D modelling of homogeneous and isotropic poroelastic materials, under timeharmonic excitations, and in the low frequency range. A model based on the Biot-Allard theory is used for the poroelastic materials, which is known to be very costly in terms of computational resources. Reduced models offer the possibility to enhance the resolution of such complex problems. However, their applicability to porous materials remained to be demonstrated.First, this thesis presents FE resolutions of poro-elasto-acoustic coupled problems using modal-based approaches both for the acoustic and porous domains. The original modal approach proposed for porous media, together with a dedicated mode selection and truncation procedure, are validated on 1D to 3D applications.In a second part, modal-reduced models are combined with a Padé approximants reconstruction scheme in order to further improve the efficiency.A concluding chapter presents a comparison and a combination of the proposed methods on a 3D academic application, showing promising performances. Conclusions are then drawn to provide indications for future research and tests to be conducted in order to further enhance the methodologies proposed in this thesis.

Das Innenohr des Säugetieres ist ein hochspezialisiertes sensorisches System, das durch ein komplexes mechanisches Verhalten gekennzeichnet ist. Neben der komplizierten Morphometrie und Geometrie kommen auch dem richtungsabhängigen Materialverhalten eine wesentliche Bedeutung zu. Es zeigt sich, daß im Cortischen Organ mit der äußeren Haarsinneszelle ein Zelltyp vorliegt, der durch seine physikalischen Eigenschaften das Gesamtverhalten des Innenohres maßgeblich beeinflußt. Wie jede tierische Zelle weist die äußere Haarsinneszelle als biomechanisches System eine heterogene Mikrostruktur auf. Vom mechanischen Standpunkt aus gesehen, ist neben der mehrschichtigen basolateralen Zellwand jede Einzelzelle durch ein viskoses inneres Fluid (Zellplasma) und einen Zellkern (Nukleus) gekennzeichnet. Die resultierenden mechanischen Eigenschaften des Gesamtsystems ”äußere Haarsinneszelle” können durch Experimente und eine geeignete Modellierung determiniert werden. In dieser Arbeit wird ein neuer Ansatz zur Bestimmung der viskoelastischen Materialeigenschaften der basolateralen Wand vorgestellt. Durch Anwendung einer effektiven Fluid-Struktur-Interaktion wird das Gesamtsystem geschlossen untersucht und eine umfangreiche Materialparameterstudie durchgeführt. Dabei werden im Rahmen der Kontinuumsmechanik gültige Materialgesetze angewendet. Das durch partielle Differentialgleichungen formulierte mechanische Feldproblem wird im Rahmen der Finiten-Elemente-Methode approximiert, was zu einem linearen Gleichungssystem führt. Auf dieser Grundlage wird ein Finite-Elemente-Modell der äußeren Haarsinneszelle entwickelt. Die zur Beschreibung notwendigen Systemmatrizen – insbesondere die Dämpfungsmatrix – basieren dabei vollständig auf einem viskoelastischen Materialgesetz. Die benutzte Methodik läßt weiterhin eine effiziente Berechnung im Frequenzbereich zu. Es zeigt sich, daß eine spezielle Dämpfungsformulierung die experimentell bestimmten dynamischen Eigenschaften der Zelle adäquat widerspiegelt. Eine Analyse auf Materialgesetzebene zeigt, daß dafür reine Schubdämpfung und damit eine spezielle Anisotropie im Viskositätstensor verantwortlich ist. Diese Eigenschaft bestimmt das dynamische Verhalten der äußeren Haarsinneszelle bis mindestens 10 kHz und liegt damit im Hörbereich. Der Modellierung der Zelle geht eine angepaßte Auswertung der experimentell ermittelten Daten voraus. Die mechanisch geeignete Auswertung der zugrundeliegenden Experimente weist dabei auf mögliche Fehlerquellen bei der Analyse der Rohdaten hin. Das hat zur Konsequenz, daß der experimentellen Umgebung die gleiche Aufmerksamkeit geschenkt werden muß wie dem Meßobjekt selbst. Nur so kann eine geeignete Extraktion der für das Meßobjekt spezifischen Eigenschaften erfolgen.

Η παρούσα διδακτορική διατριβή έχει ως στόχο την ανάλυση και έλεγχο ρευστοδυναμικών συστημάτων χρησιμοποιώντας έξυπνα υλικά όπως πιεζοκρύσταλλοι για τον σχεδιασμό επενεργητών. Στο Μέρος Ι, εκτιμάται η απόδοση μιας πρωτότυπης πιεζο-υδραυλικής αντλίας με χρήση Πεπερασμένων Στοιχείων. Η συγκεκριμένη διάταξη αποτελείται από ένα έμβολο και δύο παθητικές βαλβίδες με συχνότητα λειτουργίας μεγαλύτερη των 100Hz. Το αναπτυχθέν μοντέλο πεπερασμένων στοιχείων λαμβάνει υπόψιν την συμπιεστότητα του ρευστού, την περιορισμένη διάδοση του κύματος πίεσης, τυρβώδη ροή και αμφίδρομη αλληλεπίδραση ρευστού-στερεού των βαλβίδων. Με τα αποτελέσματα των προσομοιώσεων υπολογίστηκε η απόδοση της αντλίας και ακολούθησε παραμετρική βελτιστοποίηση κύριων παραμέτρων της βαλβίδας. Έτσι, έγινε εφικτή η λειτουργία σε υψηλότερες συχνότητες (500Hz) με βελτιωμένη απόδοση. Στην συνέχεια, μελετήθηκε ιδεατό σύστημα με ενεργές βαλβίδες ώστε να αναπτυχθούν τεχνικές ελέγχου του χρονισμού των βαλβίδων. Οι προσομοιώσεις έδειξαν σημαντικά περιθώρια βελτίωσης με ενεργές βαλβίδες, ενώ ανέδειξαν την σημασία της διάδοσης του κύματος, ιδιαίτερα κατά τον συντονισμό. Στο Μέρος ΙΙ, προτάθηκε ένας πρωτότυπος επενεργητής, βασισμένος στην εκμετάλλευση του συντονισμού του ρευστού. Αυτή η προσέγγιση επιτρέπει την μηχανική ολοκλήρωση της αντλίας μέσα στον επενεργητή, ενώ απαιτείται μόνο μια βαλβίδα υψηλής συχνότητας σε αντίθεση με υπάρχοντα συστήματα όπου απαιτούνται δύο (εισαγωγής, εξαγωγής). Ο πρωτότυπος επενεργητής μοντελοποιήθηκε με απευθείας διακριτοποίηση των εξισώσεων Navier Stokes με συμπιεστότητα και εξήχθη ένα μοντέλο χώρου κατάστασης. Παράλληλα με το μοντέλο πιεζοκρυστάλλων και της ροής της βαλβίδας ολοκληρώθηκε το μοντέλο του επενεργητή, ενώ τα βασικά στοιχεία του μοντέλου επιβεβαιώθηκαν με πειραματικά δεδομένα. Επίσης επιβεβαιώθηκε η αρχή λειτουργίας του προτεινόμενου συστήματος του επενεργητή με πειραματικές μετρήσεις. Στην τελευταία ενότητα της διατριβής αναλύονται βασικά στοιχεία με στόχο την βελτίωση της λειτουργίας του επενεργητή. / The present PhD thesis has a key object the analysis and control of fluid dynamics systems taking advantage of the smart material properties like piezocrystals for the design of actuators. In Part I, the performance of a prototype piezohydraulic pump is estimated using the Finite Element Method. The specific setup consists of a piston and two passive valves with an operating frequency greater than 100Hz. The developed Finite Element Model takes into account fluid's compressibility, the limited pressure wave propagation, turbulent flow and Fluid Structure Interaction of the valves with the fluid. Simulation results were used to calculate the pump's performance and a parametric optimization of valve's key parameters is performed. Much higher operating frequencies (500Hz) with improved performance is achieved. In the sequel, studies on a ideal active valve system are undertaken and control techniques of valve timing are developed. Simulations revealed the potential benefit from an active valve system and also revealed the importance of accounting wave propagation phenomena, especially during resonance. In Part II, a novel fluid actuator based on the exploitation of fluid resonance is proposed. This approach allows the integration of the pump within the actuator, whereas only one high frequency valve is needed, in contrast with existing systems where two high frequency valves are needed (inlet, outlet). The novel actuator is modeled using a direct discretization of the compressible Navier Stokes equations and a state space model is derived. Along with the piezoelectric and valve flow model a complete model of the actuator is formulated. The key components of the model are verified with experimental data from a prototype actuator. Also, the concept of the new actuator is proved by experimental measurements. At the last section of the thesis key aspects of the systems for further improvement of the actuator are proposed.

Fluid-structure interaction (FSI), occurrent in many areas of engineering and in the natural world, has been the subject of much research using a wide range of modelling strategies. However, problems with high levels of structural deformation are difficult to resolve and this is particularly the case for biomedical flows. A Lagrangian flow model coupled with a robust model for nonlinear structural mechanics seems a natural candidate since large distortion of the computational geometry is expected. Smoothed particle Hydrodynamics (SPH) has been widely applied for nonlinear interface modelling and this approach is investigated here. Biomedical applications often involve thin flexible structures and a consistent approach for modelling the interaction of fluids with such structures is also required. The Lagrangian weakly compressible SPH method is investigated in its recent delta-SPH form utilising inter-particle density fluxes to improve stability. Particle shifting is also used to maintain particle distributions sufficiently close to uniform to enable stable computation. The use of artificial viscosity is avoided since it introduces unphysical dissipation. First, solid boundary conditions are studied using a channel flow test. Results show that when the particle distribution is allowed to evolve naturally instabilities are observed and deviations are noted from the expected order of accuracy. A parallel development in the SPH group at Manchester has considered SPH in Eulerian form (for different applications). The Eulerian form is applied to the channel flow test resulting in improved accuracy and stability due to the maintenance of a uniform particle distribution. A higher-order accurate boundary model is developed and applied for the Eulerian SPH tests and third-order convergence is achieved. The well documented case of flow past a thin plate is then considered. The immersed boundary method (IBM) is now a natural candidate for the solid boundary. Again, it quickly becomes apparent that the Lagrangian SPH form has limitations in terms of numerical noise arising from anisotropic particle distributions. This corrupts the predicted flow structures for moderate Reynolds numbers (O(102)). Eulerian weakly compressible SPH is applied to the problem with the IBM and is found to give accurate and convergent results without any numerical stability problems (given the time step limitation defined by the Courant condition). Modelling highly flexible structures using the discrete element model is investigated where granular structures are represented as bonded particles. A novel vector-based form (the V-Model) is identified as an attractive approach and developed further for application to solid structures. This is shown to give accurate results for quasi-static and dynamic structural deformation tests. The V-model is applied to the decay of structural vibration in a still fluid modelled using Eulerian SPH with no artificial stabilising techniques. Again, results are in good agreement with predictions of other numerical models. A more demanding case representative of pulsatile flow through a deep leg vein valve is also modelled using the same form of Eulerian SPH. The results are free of numerical noise and complex FSI features are captured such as vortex shedding and non-linear structural deflection. Reasonable agreement is achieved with direct in-vivo observations despite the simplified two-dimensional numerical geometry. A robust, accurate and convergent method has thus been developed, at present for laminar two-dimensional low Reynolds number flows but this may be generalised. In summary a novel robust and convergent FSI model has been established based on Eulerian SPH coupled to the V-Model for large structural deformation. While these developments are in two dimensions the method is readily extendible to three-dimensional, laminar and turbulent flows for a wide range of applications in engineering and the natural world.

Le travail réalisé dans le cadre de cette thèse en co-tutelle concerne deux domaines d’étude de l'interaction fluide-structure. Le premier relevant du Génie Minier traite de l'interaction entre une grille mobile au sein d'un sluice et de l'écoulement confiné associé. Le second relevant de l'Hydrodynamique fondamentale porte sur l'interaction d'un cylindre monté sur appuis souples et un écoulement à surface libre en présence de fond. Notre travail contribue à l’étude des écoulements confinés à surface libre par une approche expérimentale. Nous avons couplé des techniques de visualisation par caméra CCD, de mesures de champs de vitesse par PIV et d'efforts hydrodynamiques pour qualifier la dynamique des objets en mouvement dans l'écoulement. Les méthodes et dispositifs expérimentaux sont alors appliqués à l'étude de l'écoulement autour de deux maquettes simplifiées d'un JIG à grille mobile puis à celui du cylindre vibrant sous l'effet de l'écoulement. L’acquisition par PIV suivi des traitements statistique multi-variables par POD nous a permis d'étudier l'évolution des zones de recirculation dans le compartiment ainsi que le champ de vitesse instationnaire. L’étude expérimentale a été complétée par une simulation numérique par ANSYS14.5 pour la maquette de JIG et par un modèle numérique d’oscillation du sillage pour le cylindre. Ces travaux nous ont permis de mettre en évidence une technique simple pour mettre en mouvement, dans un sluice, un filet attaché à un cylindre et d'étudier les effets du confinement sur un cylindre vibrant en présence de surface libre. / The work realized under this co-supervised thesis concerns two study areas of fluid-structure interaction. The first concerned the Mineral Engineering and deals with the interaction between a moving grate in a sluice and the confined flow associated. The second concerns the fundamental Hydrodynamics and deals with the interaction of a cylinder mounted on flexible supports and a free surface flow in presence of plane wall. Our work contributes to the study a confined free surface flow by experimental approach. We coupled techniques of CCD camera visualization, velocity fields measurements by PIV and hydrodynamic forces to qualify the dynamics of structure motion in the flow. Experimental methods and devices are applied to the study the flow around two simplified models of a moving JIG grate and then to study a vibrating cylinder due to flow. Treatments of PIV data acquisitions by multivariable statistical POD enabled us to describe evolution of recirculation zones in the compartment and unsteady velocity field. Experimental study was completed by a numerical simulation of Jig model by using ANSYS14.5 and a numerical wake oscillator model for the case of the cylinder. This work highlighted a simple technique to give motion, in a sluice, a attached net to a cylinder and to study effects of free surface flow confinement on a vibrating cylinder

L'objectif de cette thèse est d'améliorer la compréhension des phénomènes jouant un rôle dans la mesure effectuée dans un analyseur sanguin, en particulier le comptage et la mesure de volumétrie d'une population de globules rouges reposant sur l'effet Coulter. Des simulations numériques sont effectuées dans le but de prédire la dynamique des globules rouges dans les zones de mesure et pour reproduire la mesure électrique associée, servant au comptage et à la volumétrie des cellules. Ces simulations sont effectuées à l'intérieur de configurations industrielles d'analyseur sanguin, en utilisant un outil numérique développé à l'IMAG, le solveur YALES2BIO. En utilisant la méthode des frontières immergées avec suivi de front, un modèle de particule déformable est introduit, celui-ci prend en compte le contraste de viscosité ainsi que les effets mécaniques de la courbure et de l'élasticité sur la membrane. Le solveur est validé grâce à de nombreux cas tests parcourant différents régimes et effets physiques. L'écoulement fluide dans cette géométrie d'analyseur sanguin est caractérisée par un fort gradient de vitesse axial dans la direction de l'écoulement, impliquant la présence d'un écoulement extensionnel au niveau du micro-orifice, là où a lieu la mesure. La dynamique des globules rouges est étudiée par des simulations numériques pour différentes conditions initiales, telles que sa position ou son orientation. Il est observé que les globules rouges vont se réorienter selon l'axe principal de l'analyseur sanguin dans tous les cas. Pour comprendre le phénomène, des modèles analytiques sont adaptés au cas des écoulements extensionnels et reproduisent correctement les tendances de réorientation.Cette thèse présente également la reproduction de la mesure électrique utilisée pour le comptage et la mesure de la distribution des volumes de globules rouges. De nombreuses simulations de la dynamique des globules rouges sont effectuées et utilisées pour générer l'impulsion électrique correspondant au passage du globule rouge dans le micro-orifice. Les amplitudes d'impulsions électriques résultantes permettent la caractérisation de la réponse électrique en fonction des paramètres initiaux de la simulation par une approche statistique. Un algorithme de Monte-Carlo est utilisé pour la quantification des erreurs de mesure liées à l'orientation et la position des globules rouges dans le micro-orifice. Ceci permet la génération d'une distribution de volume mesurée pour une population de globules rouges bien définie et la caractérisation des erreurs de mesure associées. / The aim of this thesis is to improve the understanding of the phenomena involved in the measurement performed in a blood analyzer, namely the counting and sizing of red blood cells based on the Coulter effect. Numerical simulations are performed to predict the dynamics of red blood cells in the measurement regions, and to reproduce the associated electrical measurement used to count and size the cells. These numerical simulations are performed in industrial configurations using a numerical tool developed at IMAG, the YALES2BIO solver. Using the Front-Tracking Immersed Boundary Method, a deformable particle model for the red blood cell is introduced which takes the viscosity contrast as well as the mechanical effects of the curvature and elasticity on the membrane into account. The solver is validated against several test cases spreading over a large range of regimes and physical effects.The velocity field in the blood analyzer geometry is found to consist of an intense axial velocity gradient in the direction of the flow, resulting in a extensional flow at the micro-orifice, where the measurement is performed. The dynamics of the red blood cells is studied with numerical simulations with different initial conditions, such as its position or orientation. They are found to reorient along the main axis of the blood analyzer in all cases. In order to understand the phenomenon, analytical models are adapted to the case of extensional flows and are found to reproduce the observed trends.This thesis also presents the reproduction of the electrical measurement used to count red blood cells and measure their volume distribution. Numerous dynamics simulations are performed and used to generate the electrical pulse corresponding to the passage of a red blood cell inside the micro-orifice. The resulting electrical pulse amplitudes are used to characterize the electrical response depending on the initial parameters of the simulation by means of a statistical approach. A Monte-Carlo algorithm helps quantifying the errors on the measurement of cell depending on its orientation and position inside the micro-orifice. This allows the generation of a measured volume distribution of a well defined red blood cell population and the characterization of the associated measurement errors.

This thesis analyses the impact of granular aggregates with structures using experiments and numerical simulations. Original contributions include an insight into multiple factors affecting the loading and damage to the structures, along with study of numerical parameters important for realistic prediction of the interaction between the granular media and structures. It extends the current understanding related to such interactions, with an underlying motivation to guide strategies in order to reduce the structural damage. The response of structures impacted by granular media (sand or soil) is of significant research interest for many applications. One of the applications is for landmine explosions which causes ejection of soil from ground and damage to structures impacted by this ejected soil. Experimentation is done in a laboratory setting where the cylindrical sand slugs are generated at high speed using an impulse provided by a piston. This induces a velocity gradient along the slug, because of which the slug expands during the flight before impacting the target. Deformable as well as rigid flat targets are considered in two orientations relative to the incoming slug: perpendicular (i.e. normal orientation) and inclined at an angle of 45°. The targets are supported by force transducers to capture the loading from the slug. Simulations are performed using a combination of discrete particle and finite element schemes, which enables the analysis of the fully coupled interaction between the flowing granular media and the structure. A contact model involving multiple parameters is used for inter-particle and particle-target contact. Firstly, a numerical analysis is performed to characterise the temporal evolution of slugs and their impact on monolithic beams constrained at the ends. Out of all the parameters used for inter-particle contact definition in discrete particle method, only the contact stiffness is found to effect the velocity gradient in the slug before it impacts the target. Other factor influencing the gradient is the acceleration provided by the piston. A strong dependence of beam deflection on the stand-off distance is observed due to the velocity gradient in the slugs. As the second step, the effect of target surface properties on the transmitted momentum is analysed. Experiments are done by applying coatings of different hardness and roughness on the target surface impacted by sand slugs. For normally oriented targets, the transmitted momentum is observed to be insensitive to the change in surface coating. In contrast, for inclined targets, a significant influence of coatings is observed. Additionally, the momentum transmitted to the inclined targets is always less than that for normal targets. Numerical analysis of this surface effect reveals that assuming the slug particles to be spherical shape in simulations does not capture the particle/target interactions accurately and under-predicts the frictional loading on the target. Following this, a detailed numerical study is done to understand the effect of the shape of particles in the slug. Simple shaped non-spherical particles are constructed by combining spherical sub-particles. With increasing angularity of particles in the slug, the frictional loading on the target is shown to increase. This results in an increase of momentum transmitted to inclined targets. For normally oriented targets however, the particle shape does not affect the overall transmitted momentum, which is a behaviour similar to that observed when studying the effect of target surface properties. In addition, effect of fracture of particles in the slug is analysed by using beam connections between sub-particles that break during the impact with the target. If the fracture results in increasing particle angularity, the transmitted momentum increases, whereas the situation reverses if fracture results on more spherical shaped particles. Lastly, a strategy to reduce the loading on the targets is analysed by using sacrificial coating on the target surface. In experiments, this coating is placed on the rigid target surface using a lubricant at their interface. When impacted by the slug, this coating slides on the target surface, resulting in a reduction of frictional loading on the target. If the friction at the coating/target interface vanishes, the transmitted momentum approaches the theoretical minimum value. Simulations are used to first validate the experimental observations and then to extend the concept of sliding coatings using deformable targets. Both the transmitted momentum and deflections depended on the thickness of the target and coating. When a coating is used, the deflections increase due to reduction in target thickness. It is found that the best strategy to reduce the damage to the target is to use least possible thickness of the coating and minimise the friction at the interface between the coating and the target. The presented work examines many of the factors that affect the loading on the target impacted by granular slugs, in addition to characterising the expansion of slugs before the target impact. The analysed factors include those already known such as target stand-off distance, inclination and unveils others such as target surface properties and granular properties. The numerical analysis discloses important parameters and shows the effect of particle shape, highlighting the shortcomings of widely used spherical particle assumption in the numerical studies. A strategy using a sacrificial coating to reduce damage to the target is also analysed.

O objetivo deste trabalho é estudar e desenvolver procedimentos numéricos adequados para a análise de problemas da Engenharia do Vento Computacional (EVC). O escoamento é analisado a partir das equações de Navier-Stokes para um fluido Newtoniano e de uma equação de conservação de massa considerando a hipótese de pseudo-compressibilidade, ambas em um processo isotérmico. Na presença de escoamentos turbulentos emprega-se a Simulação de Grandes Escalas (“LES”) com os modelos clássico e dinâmico de Smagorinsky para as escalas inferiores à resolução da malha. Dois modelos numéricos de Taylor-Galerkin para a análise do escoamento são estudados: o esquema explícito de dois passos e o esquema explícito-iterativo. O Método dos Elementos Finitos (MEF) é empregado para a discretização do domínio espacial utilizando o elemento hexaédrico trilinear isoparamétrico com integração reduzida das matrizes em nível de elemento. Em problemas envolvendo efeitos de interação fluido-estrutura emprega-se um esquema de acoplamento particionado com características superiores de conservação, permitindo, inclusive, o uso de subciclos entre as análises do fluido e da estrutura e de malhas não compatíveis na interface. A estrutura é considerada como um corpo deformável constituído de um material elástico linear com a presença de nãolinearidade geométrica. O MEF é também usado para a discretização da estrutura, empregando-se para tanto o elemento hexaédrico trilinear isoparamétrico com integração reduzida e controle de modos espúrios. A equação de equilíbrio dinâmico é integrada no tempo utilizando o método implícito de Newmark no contexto do método de estabilização α- Generalizado. Na presença de estruturas deformáveis, o escoamento é descrito através de uma formulação arbitrária Lagrangeana-Euleriana (ALE). Ao final, comparações com exemplos numéricos e experimentais são apresentadas para demonstrar a viabilidade dos algoritmos desenvolvidos, seguindo-se com as conclusões do trabalho e as sugestões para trabalhos futuros. / Analysis and development of numerical tools to simulate Computational Wind Engineering (CWE) problems is the main goal of the present work. The isothermal flow is analyzed using the Navier-Stokes equations for viscous fluids and a mass conservation equation obtained according to the pseudo-compressibility assumption. Turbulent flows are simulated employing Large Eddy Simulation (LES) with the classical and dynamic Smagorinsky’s models for subgrid scales. Two Taylor-Galerkin models for the flow analysis are investigated: the explicit two-step scheme and the explicit-iterative scheme. The Finite Element Method (MEF) is employed for spatial discretizations using the eight-node hexahedrical isoparametric element with one-point quadrature. Fluid-structure interaction problems are analyzed with a coupling model based on a conservative partitioned scheme. The Finite Element Method (MEF) is employed for spatial discretizations using the eight-node hexahedrical isoparametric element with one-point quadrature. Fluid-structure interaction problems are analyzed with a coupling model based on a conservative partitioned scheme. Subcycling and nonmatching meshes for independent discretizations of the fluid and structure domains are also available. The structure is considered as a deformable body constituted by a linear elastic material with geometrically nonlinear effects. The FEM is used for the spatial discretization of the structure as well. Eight-node hexahedrical isoparametric elements with one-point quadrature and hourglass control are adopted in this process. The implicit Newmark algorithm within the framework of the α-Generalized method is employed for the numerical integration of the dynamic equilibrium equation. An arbitrary Lagrangean-Eulerian (ALE) description is adopted for the kinematic description of the flow when deformable structures are analyzed. Numerical and experimental examples are simulated in order to demonstrate the accuracy of the developed algorithms. Concluding remarks and suggestions for future works are pointed out in the last chapter of the present work.