Turbulent flows and coherent structures emerging within turbulent flow fields have been extensively studied for the past few decades and a wide variety of experimental and numerical techniques have been developed for measurement and analysis of turbulent flows. The complex nature of turbulence requires methods that can accurately estimate its highly chaotic spatial and temporal behavior. Some of the classical cases of turbulent flows with simpler geometries have been well characterized by means of the existing experimental techniques and numerical models. Nevertheless, since most turbulent fields are of complex geometries; there is an increasing interest in the study of turbulent flows through models with more complicated geometries. In this dissertation, characteristics of turbulent flows through two different facilities with complex geometries are studied applying two different experimental methods. The first study involves the investigation of turbulent impinging jets through a staggered array of rods with or without crossflow. Such flows are crucial in various engineering disciplines. This experiment aimed at modeling the coolant flow behavior and mixing phenomena within the lower plenum of a Very High Temperature Reactor (VHTR). Dynamic Particle Image Velocimetry (PIV) and Matched Index of Refraction (MIR) techniques were applied to acquire the turbulent velocity fields within the model. Some key flow features that may significantly enhance the flow mixing within the test section or actively affect some of the structural components were identified in the velocity fields. The evolution of coherent structures within the flow field is further investigated using a Snapshot Proper Orthogonal Decomposition (POD) technique. Furthermore, a comparative POD method is proposed and successfully implemented for identification of the smaller but highly influential coherent structures which may not be captured in the full-field POD analysis. The second experimental study portrays the coolant flow through the core of an annular pebble bed VHTR. The complex geometry of the core and the highly turbulent nature of the coolant flow passing through the gaps of fuel pebbles make this case quite challenging. In this experiment, a high frequency Hot Wire Anemometry (HWA) system is applied for velocity measurements and investigation of the bypass flow phenomena within the near wall gaps of the core. The velocity profiles within the gaps verify the presence of an area of increased velocity close to the outer reflector wall; however, the characteristics of the coolant flow profile is highly dependent on the gap geometry and to a less extent on the Reynolds number of the flow. The time histories of the velocity are further analyzed using a Power Spectra Density (PSD) technique to acquire information about the energy content and energy transfer between eddies of different sizes at each point within the gaps.

Afin d'élaborer des stratégies de contrôle des écoulements en temps réel, il est nécessaire d'avoir recours à des modèles d'ordre réduit (ROMs), car la résolution des équations complètes est trop coûteuse en temps de calcul (des jours, des semaines) et en espace mémoire. Dans cette thèse, les modèles réduits ont été construits avec la méthode POD (Proper Orthogonal Decomposition). Une méthode de projection basée sur la minimisation des résidus, initiée par les travaux de Leblond et al. [134] a été proposée. Dans certaines configurations, la précision des résultats est significativement augmentée, par rapport à une projection de Galerkin classique. Dans un second temps, un algorithme d'optimisation non-linéaire, à direction de descente basée sur la méthode des équations adjointes, a été couplé avec des modèles réduits utilisant des bases POD. Deux méthodes de construction de base POD ont été employées : soit avec un paramètre (un nombre de Reynolds,. . . ), soit avec plusieurs paramètres (plusieurs nombres de Reynolds, . . . ). Les ROMs obtenus ont été utilisés pour contrôler la dispersion d'un polluant dans une cavité ventilée puis pour contrôler le champ de température dans une cavité entraînée différentiellement chauffée. Le contrôle est réalisé en temps quasi-réel et les résultats obtenus sont plutôt satisfaisants. Néanmoins, ces méthodes sont encore trop coûteuses en espace mémoire pour être aujourd'hui embarquées dans les boîtiers de contrôle utilisés dans le bâtiment. Une autre stratégie de contrôle, s'appuyant sur les contrôleurs actuels, a ainsi été développée. Celle-ci permet d'obtenir la température (ainsi que la vitesse) dans la zone d'occupation du bâtiment, en utilisant une décomposition des champs par POD et un algorithme d'optimisation de Levenberg-Marquardt. Elle a été validée sur une cavité différentiellement chauffée, puis appliquée sur une cavité ventilée 3D, proche d'un cas réel.

Dans le milieu aéronautique, la simulation numérique s'est largement imposée dans le développement industriel des systèmes complexes. De la conception au suivi en service, les simulations numériques sont nombreuses et variées. Afin de proposer des méthodes alternatives aux méthodes de calcul intensif, la réduction de modèle permet de réduire considérablement le coût de la résolution numérique des problèmes non linéaires en projetant les équations aux dérivées partielles sur une base réduite. De plus, la description des phénomènes physiques requiert une loi de comportement élaborée dont une simplification est considérée en exploitant une partie restreinte du domaine spatial. Les études effectuées ont pour but d'apporter certains développements à la méthode incrémentale et adaptative A Priori Hyper Reduction dans le cas des matériaux hétérogènes. Ces développements sont intégrés dans le code éléments finis Z-set et utilisés pour traiter une série d'exemples académiques sur des structures composites.

Combustion instability due to feedback coupling between unsteady heat release and natural acoustic modes can cause catastrophic failure in liquid rocket engines and to predict and prevent these instabilities the mechanisms that drive them must be further elucidated. With this goal in mind, the objective of this thesis was to develop techniques that improve the understanding of the specific underlying physical processes involved in these driving mechanisms. In particular, this work sought to develop a small-scale, optically accessible liquid rocket engine simulator and to apply modern, high-speed diagnostic techniques to characterize the reacting flow and acoustic field within the simulator. Specifically, high-speed (10 kHz), simultaneous data were acquired while the simulator was experiencing a 170 Hz combustion instability using particle image velocimetry, OH planar laser induced fluorescence, CH* chemiluminescence, and dynamic pressure measurements. In addition, this work sought to develop approaches to reduce the large quantities of data acquired, extracting key physical phenomena involved in the driving mechanisms. The initial data reduction approach was chosen based on the fact that the combustion instability problem is often simplified to the point that it can be characterized by an approximately linear constant coefficient system of equations. Consistent with this simplification, the experimental data were analyzed by the dynamic mode decomposition method. The developed approach to apply the dynamic mode decomposition to simultaneously acquired data located a coupled hydrodynamic/combustion/acoustic mode at 1017 Hz. On the other hand, the dynamic mode decomposition's assumed constant operator approach failed to locate any modes of interest near 170 Hz. This led to the development of two new data analysis techniques based on the dynamic mode decomposition and Floquet theory that assume that the experiment is governed by a linear, periodic system of equations. The new periodic-operator data analysis techniques, the Floquet decomposition and the ensemble Floquet decomposition, approximate, from experimental data, the largest moduli Floquet multipliers, which determine the stability of the periodic solution trajectory of the system. The unstable experiment dataset was analyzed with these techniques and the ensemble Floquet decomposition analysis found a large modulus Floquet multiplier and associated mode with a frequency of 169.6 Hz. Furthermore, the approximate Rayleigh criterion indicated that this mode was unstable with respect to combustion instability. Overall, based on the positive finding that the ensemble Floquet decomposition was able to locate an unstable combustion mode at 170 Hz when the operator's time period was set to 1 ms, suggests that the dynamic mode decomposition based 1017 Hz mode parametrically forces the 170 Hz mode, resulting in what could be characterized as a parametric combustion instability.

Turbulent flow inside a street canyon was investigated in an open circuit wind tunnel and in a blow-down wind channel. Two geometries were used for comparison purposes: buildings with pitched roofs and with flat roofs. Both generate the flow of a different category, so the induced ventilation regimes are fundamentally different. Quadrant, Fourier and Wavelet analysis, Proper Orthogonal Decomposition (POD) and vortex detection methods are used to identify coherent structures in the flow and establish their impact on the ventilation of pollution. Two types of the organised motions are detected: the compact areas of sweep and ejection with the scale comparable to the size of building and the small vortices generated in the shear layer behind the building roof. POD identifies the most dominant modes with high coherency in the flow and evaluates the relative contributions of each mode to the overall kinetic energy of turbulence. Rigorous analysis of the correctness of the physical interpretation for such a decomposition is carried out. Wavelet analysis is applied to the time-series of the POD expansion coefficients in order to reveal control mechanism of the dynamics of the modes. Vorticity, calculated from the original velocity data, is decomposed by POD as well. Finally, the correlation between the vorticity...

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

The Czech Republic has a very dense network of waterways and a lot of lakes and small ponds. Floods belong to the most frequent natural disasters in the CR. Small water reservoirs in the flood protection system are of great importance. The retention capacity of those water reservoirs and feasibility to control water outflow are used. The aim of this study is to determine the state of preparedness to manage consequences of a possible failure and an accident on one of such water-works of category II, the pond Hvězda. Vulnerability of the area is assessed in terms of preparedness of state and local government authorities responsible for special flood consequences management. Meeting this objective is possible through compliance with the methodological procedure. The procedure implies studying legislation and normatives applied to the area, flood protection, population protection and crisis management. And it also involves evaluation of responsible institutions and the status of their documents concerning planning, and making comparisons with legislation requirements. Another objective is a proposal of my own solutions to the identified failures management. This is a project of planning documents completion, to be specific, a plan for the area below the water-works protection. The plan is a general conception and allows itself to be used for any water-work. The thesis also includes a brief elaboration of educational material in the form of a presentation, designed for involved authorities that are supposed to compile the plan, or to participate in its compilation. The objective, content and the method of the plan preparation are outlined. It is useful to inform the entities involved in the special flood management such as the Fire Prevention Unit, the Integrated Rescue System components about this issue. This thesis offers a solution to a specific problem, which is protection of inhabitants and areas located below water-works against a special flood impact. It also suggests the future view of an area vulnerability assessment, which consists in a comprehensive hazard mapping and its evaluation according to a unified methodology in the CR territory and assuring its compatibility within the EU.

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-06-29T22:20:43Z No. of bitstreams: 2 Dissertação - Ingrid Luz Guimarães - 2017.pdf: 1402447 bytes, checksum: 7d2b3bc12c14d9a3bd34392e4f9d7049 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-07-10T10:46:04Z (GMT) No. of bitstreams: 2 Dissertação - Ingrid Luz Guimarães - 2017.pdf: 1402447 bytes, checksum: 7d2b3bc12c14d9a3bd34392e4f9d7049 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-07-10T10:46:05Z (GMT). No. of bitstreams: 2 Dissertação - Ingrid Luz Guimarães - 2017.pdf: 1402447 bytes, checksum: 7d2b3bc12c14d9a3bd34392e4f9d7049 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Soybean pre-cleaning residue is found in large quantities in the processing and processing dryers' farms, resulting in serious inconvenience if it is not removed to farther places before the fermentation process begins. Among the residues generated at the time of harvesting and cleaning of the grains are soybean pods, which presents as an alternative lignocellulosic material to be used in the production of Agglomerated panels of the MDP type. The objective of this work was to verify the effect of the use of soybean pods in the production of eucalyptus MDP panels. The panels, with a nominal density of 0.70 g / cm³, were composed of three layers, the thin layers of eucalyptus wood were used in the covers and the core was composed of a mixture of eucalyptus particles and soybean pods. The proportions used of soybean residue particles in relation to those of eucalyptus in the kernels were 0, 25, 50, 75 and 100%. For the glueing of the particles the adhesive urea formaldehyde, in the proportion of 12%, was used for both the covers and the crumb. The pressing cycle had a temperature of 160 ° C for a period of 15 minutes at a pressure of 4MPa. To evaluate the quality of the panels produced, their physical and mechanical properties of apparent density; Compaction ratio; Water absorption and swelling in thickness at 2 and 24 hours of immersion were determinater; Perpendicular traction; Modulus of elasticity and modulus of rupture in the static bending. To meet the requirements of Brazilian standard (NBR 14.810 / 2002), for the properties of swelling in thickness (2h) and modulus of rupture, the maximum amount of soybean recommended for MDP panels is 20%. / O resíduo da pré-limpeza de soja é encontrado em grande quantidade no pátio das indústrias de beneficiamento e dos secadores das fazendas, acarretando sérios transtornos caso não seja removido para locais mais afastados antes que o processo de fermentação se inicie. Dentre os resíduos gerados no momento da colheita e limpeza dos grãos estão às vagens de soja, que se apresenta como um material lignocelulósico alternativo para ser utilizado na produção de painéis aglomerados do tipo MDP. Este trabalho teve como objetivo verificar o efeito da utilização de vagens de soja na produção de painéis MDP de eucalipto. Os painéis, com densidade nominal de 0,70 g/cm³, foram constituídos por três camadas, de modo que nas capas foram utilizadas finas partículas de madeira de eucalipto e o miolo foi composto por uma mistura de partículas de eucalipto e de vagens soja. As proporções utilizadas de partículas de resíduo de soja em relação às de eucalipto no miolo foram de 0, 25, 50, 75 e 100%. Para o encolamento das partículas foi utilizado o adesivo uréia formaldeído, na proporção de 12%, tanto para as capas como para o miolo. O ciclo de prensagem teve temperatura de 160°C, por um período de 15 minutos a uma pressão de 4MPa. Para avaliar a qualidade dos painéis produzidos, foram determinadas suas propriedades físicas e mecânicas de densidade aparente; razão de compactação; absorção de água e inchamento em espessura em 2 e 24 horas de imersão; tração perpendicular; módulo de elasticidade e módulo de ruptura na flexão estática. Para atender as exigências da norma brasileira (NBR 14.810/2002), para as propriedades de inchamento em espessura (2h) e módulo de ruptura, a quantidade máxima de vagem de soja recomendada para painéis MDP é de 20%.

Vanilla planifolia, orchidée épiphite florifère, est la principale source naturelle de l'arôme de vanille. Largement utilisé dans les produits laitiers, les boissons, les pâtisseries et les parfums, cet arôme est le résultat d'un processus complexe : de huit à neuf mois après la fécondation des fleurs, les gousses matures sont récoltées et traitées pendant environ un an afin de libérer leur bouquet aromatique. Aujourd'hui, plus de la moitié de la production mondiale de vanille provient de Madagascar. Pour faire face à cette concurrence, les producteurs de la Réunion se tournent vers la production de vanille "haut de gamme". L'exploitation des vanilliers les plus intéressants du point de vue aromatique est donc favorisée. Toutefois, les programmes d'amélioration se heurtent au manque de connaissances sur la physiologie de la plante. Il devient alors essentiel de mieux comprendre les mécanismes physiologiques et biochimiques impliqués dans la production aromatique des gousses de V. planifolia. Dans ce travail de thèse, une analyse des métabolites présents dans les gousses vertes et les feuilles de vanille a été effectuée par Résonance Magnétique Nucléaire. Cette technique permet l'évaluation qualitative et quantitative des métabolites primaires (sucres, acides animés et organiques...) et secondaires (composés phénoliques...) présents dans la plante dans diverses conditions physiologiques : au cours du développement de la gousse, lors d'une infection virale, selon les saisons ou encore sur différentes accessions. / Vanilla planifolia, a flowering epiphitic orchid, is the major natural source of vanilla flavour. Largely used in dairy products, beverages, bakeries and perfume, vanilla flavour is obtained after a long process: from eight to nine months after flower pollinisation, mature pods are harvested and then prepered during about one year in order to release the characteristic vanilla aroma. Nowadays, more than half vanilla pods world production comes from Madagascar. To face the concurrence, a solution could be develop higher quality pods. Selection of the most aromatic vanilla plant is then preferred. Nevertheless, amelioration program are facing up to a lack of knowledge in vanilla plant physiology. It is now essential to understand more the physiological and biochemical mechanisms implied in the aromatic production of V. planifolia pods. In this thesis, a metabolomic analysis of vanilla green pods and leaves has been performed by nuclear magnetic resonance. This technique has allowed the qualitative and quantitative analysis of primary (sugar, amino and organic acids...) and secondary metabolites (phenolic compounds...) present in vanilla plant according to various physiological conditions: developing pods, viral infection, inter-accession or seasonal variation.

This thesis is concerned with the legislature of the Czech Republic, Bundesrepublik Deutschland and the Republic of France, as regards the anonymous abandonment of children in babyboxes, anonymous births and births with the identity of the mo- ther classified. It presents a complex overview of the legal framework in which the above mentioned institutions are functioning, from the point of view of the current legislation and factual state of affairs, set in the background of historical evolution of the individual institutes in individual states. The first chapter of the thesis de- als with the terminology, which in these questions is often somewhat confused and confusing, due to laymen influences and translations between languages. The se- cond chapter presents the current legal framework of the individual states, together with the umbrella framework of the international Agreements which are binding to all three of the countries. The third chapter deals with babyboxes, describing their functioning in Germany and in the Czech Republic. The fourth chapter presents the issue of anonymous births and of the french l'accouchement sous X, which is on the line between the anonymous birth and the birth with the identity of the mother classified. Fifth chapter is concerned with the births with classified identity...