Le dimensionnement préliminaire d’un propulseur hybride passe par une phase d’essais à échelle réduite afin de caractériser entre autre la loi de régression du couple oxydant/combustible envisagé pour remplir les besoins de la mission en terme de performances, durée de fonctionnement, etc. Afin de limiter le recours à ces campagnes expérimentales onéreuses et génératrices de délais pour les industriels, il est nécessaire de développer des outils numériques fiables permettant de prévoir rapidement, sous différentes conditions de fonctionnement et géométries de chambre de combustion, la loi de régression d’un couple oxydant/combustible. L’objectif de cette thèse est de proposer une modélisation monodimensionnelle du mécanisme de régression des combustibles liquéfiables. Cette classe de combustibles offre des vitesses de régression trois à cinq fois plus élevées que celles rencontrées avec les combustibles généralement utilisés en propulsion hybride (PBHT par exemple). Ce modèle se base alors sur le transport de la phase gazeuse et du film liquide se développant sur le combustible solide, la vitesse de régression dépendant des transferts de masse et d’énergie entre ces trois phases. Afin de valider cette approche et l’architecture du code Hydres conçu pour la résolution de ce modèle et la prévision des performances propulsives d’un moteur hybride, des campagnes expérimentales ont été réalisées sur les bancs d’essais Hycarre et Hycom. Ces essais ont également permis de développer une technique de mesure permettant l’obtention de la vitesse de régression instantanée du combustible, conduisant à la restitution de la loi de régression instantanée du couple oxydant/combustible. / The preliminary design of a hybrid rocket engine requires lab-scale tests to characterize the regression law of the oxidizer/fuel pair intended to fulfil the mission needs in terms of performances, etc. To limit these costly and potentialy delaying experimental campaigns, it is necessary to develop reliable numerical tools to quickly predict the regression law of the oxidiser/fuel pair under different operating conditions and with different combustion chamber geometries. The objective of the thesis is to develop a one-dimensional model of the regression mechanism of liquefying fuels. These particular fuels offer regression rates three to five times higher than those found with classic polymers used in hybrid propulsion (eg. HTPB). The model is based on the transportof the gaseous flow and the liquid film which is developing along the solid fuel grain. The regression rate depends on mass and energy transfers between these three phases. To validate this approach and the Hydres numerical tool, specifically designed to solve this model and forecast the performances of a hybrid engine, experimental tests were performed with the Hycarre and Hycom facilities. These tests also allowed for the development of a technique to measure the instantaneous regression rate of the solid fuel, providing directly the instantaneous regression law of the oxidizer/fuel pair.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-03-29T18:21:36Z No. of bitstreams: 1 DissMCAad.pdf: 6301246 bytes, checksum: 1a4544ba506998d2e95d6d0e3106cbc2 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-03T20:08:32Z (GMT) No. of bitstreams: 1 DissMCAad.pdf: 6301246 bytes, checksum: 1a4544ba506998d2e95d6d0e3106cbc2 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-03T20:08:41Z (GMT) No. of bitstreams: 1 DissMCAad.pdf: 6301246 bytes, checksum: 1a4544ba506998d2e95d6d0e3106cbc2 (MD5) / Made available in DSpace on 2017-04-03T20:13:28Z (GMT). No. of bitstreams: 1 DissMCAad.pdf: 6301246 bytes, checksum: 1a4544ba506998d2e95d6d0e3106cbc2 (MD5) Previous issue date: 2016-08-31 / Não recebi financiamento / The structural modeling of mult-storey buildings using the simplified model in which the slabs is calculated in isolation and their efforts transferred to a three-dimensional frames is now overcome by the state of the art computational analysis. Currently even with structures formed by bar elements (three-dimensional frames) it is possible to make the analysis considering the effect monolithic of concrete structures or operating as a whole. For certain cases, it is essential to consider all the structural elements participating in the bracing to the structure is presented stable in the horizontal actions combined with vertical actions, such as the flat slabs systems.Through of analysis examples of structures of buildings with multiple floors in reinforced concrete are presented advantages in performing three-dimensional modeling, comparing the results obtained with the simplified models. It shows the importance of considering the slab stiffness in flat slabs systems and how the distribution of efforts to change the three-dimensional model. Analyses are done using commercial software tool allowing verify quantitative variation of structural materials. Finally an analysis is made of the examples made showing the main differences in the new models. / A modelagem estrutural de edifícios de múltiplos andares usando o modelo simplificado no qual o pavimento é calculado de forma isolada e seus esforços transferidos para um pórtico tridimensional hoje está superada pelo estado da arte da análise computacional. Atualmente mesmo com estruturas constituídas por elementos de barras (pórticos tridimensionais) já é possível fazer a análise considerando o efeito monolítico das estruturas de concreto, ou seja, funcionando com um todo. Para determinados casos, é fundamental a consideração de todos os elementos estruturais participando do contraventamento para que a estrutura se apresente estável frente às ações horizontais combinadas com as ações verticais, como, por exemplo, os sistemas de lajes lisas. Por meio das análises de alguns exemplos de estruturas de edifícios de múltiplos pavimentos de concreto armado são apresentadas as vantagens em se realizar a modelagem tridimensional, comparando-se os resultados obtidos com os dos modelos simplificados. Mostra-se a importância da consideração da rigidez da laje em sistemas de lajes lisas e como a distribuição de esforços se altera no modelo tridimensional. As análises são feitas através de ferramenta computacional comercial permitindo assim verificar a variação de quantitativo de materiais estruturais. Por fim é feita uma análise dos exemplos realizados mostrando as principais diferenças encontradas nos novos modelos.

Orientador: Jose Roberto Nunhez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T08:15:27Z (GMT). No. of bitstreams: 1 Lopes_GabrielaCantarelli_M.pdf: 1710566 bytes, checksum: efab0c6308734536b15c2ef91d4d8337 (MD5) Previous issue date: 2008 / Resumo: Processos que envolvem escoamentos de fluidos no interior de dutos estão presentes em muitas aplicações industriais. Na indústria petroquímica um desses processos que vem se tornando cada vez mais importante é o craqueamento catalítico de frações pesadas do petróleo, já que as converte em frações leves e mais nobres. Por causa da crescente demanda mundial por gasolina e GLP e à sua alta rentabilidade para uma refinaria de petróleo, unidades de craqueamento catalítico em leito fluidizado (FCC) estão presentes em todo o mundo. Testes experimentais costumam ser usados no estudo dos fenômenos envolvidos nesse processo. Porém esse tipo de análise possui alto custo, que pode ser reduzido com o uso de simulações computacionais em seu estudo inicial. Assim, o objetivo deste trabalho foi desenvolver um modelo tridimensional e elíptico, em linguagem Fortran, capaz de fornecer dados para a análise preliminar de escoamentos no interior de reatores de FCC. Na modelagem desses problemas são usadas equações diferenciais parciais, e essas não possuem solução analítica conhecida, sendo necessário o emprego de métodos numéricos para esse fim. Neste trabalho foi usado o Método dos Volumes Finitos, que tem a função de substituir as equações diferenciais parciais por equações algébricas aplicadas a pequenos volumes de controle finitos pertencentes ao domínio. Uma das maiores dificuldades encontradas no tratamento numérico de escoamentos incompressíveis é a determinação de um campo de pressão que satisfaça a Equação da Continuidade. Esse problema foi resolvido fazendo-se uso da abordagem acoplp.da de solução. Para análise do modelo foram obtidos perfis numéricos de velocidade e pressão para fluidos escoando em regimes laminar e turbulento, que foram validados usando-se os dados obtidos com a solução analítica das equações, por correlações (semi-) empíricas ou por dados experimentais, conforme cada um dos casos. Notou-se que o modelo representa muito bem casos laminares, e gue 11.oS casos turbulentos foi necessário um maior refino da malha próximo a parede do tubo. Também foram feitas simulações para que se pudessem observar as características tridimensionais, elípticas e transientes da modelagem do escoamento. De maneira geral o modelo se mostrou bastante rápido, convergindo em poucas iterações. Palavras-Chave: Fluidodinâmica computacional; dutos cilíndricos; modelo tridimensional e elíptico; método dos Volumes Finitos; solução acoplada; turbulência / Abstract: Processes involving fluid flow in tubes are present in many industrial applications. In petrochemical industry one of these processes that are becoming more and more important is the fluid catalytic cracking of heavy petroleum fractions. This fact is due to the process capacity to convert heavy fractions in light and valuable ones. Because of the increasingly worldwide demand for gasoline and LPG and its high yield for a petroleum refinery, fluid catalytic cracking (FCC) units are present in the whole world. Experimental tests are used in the study of the phenomena involved in this processo However this kind of analysis has high cost which can be reduced by using computational simulations in its initial study. Thus, the aim of this work was the development of a three-dimensional and elliptical mo dei in Fortran language in order to provide data for fluid flow preliminary analysis in FCC reactors. Partial differential equations were used in the modeling of these problems. These equations do not have known analytical solution, being necessary therefore the use of numerical methods. In this work the Finite Volume Method were applied with this purpose. This method has as a role to substitute the partial differential equations of the mo dei for algebric equations applied to small finite control volumes of the domain. One of the biggest difficulties found in the numerical treatment of incompressible fluid flows is the determination of apressure field that satisfies the Continuity Equation. This problem was solved using the coupled solution approach. For model analysis, numerical velocity and pressure proJ:iles for laminar and turbulent flows were obtained, that had been validated using the data obtained through the analytical solution of the equations, by empirical correlations or by experimental data, according to each one of the cases. The model represented well laminar cases, and in the turbulent ones the mesh had to be more refined near the tube wall. Other simulations were performed, in aQalyzing the three-dimensional, elliptical and transient model characteristics. In general, the mo dei was very fast, converging in a few interations. Keywords: Computational fluid dyn~mic; cylindrical ducts; three-dimensional and elliptical model; Finite Volume Method; coupled solution; turbulence / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

Depuis quelques années, les modèles 0D trouvent un regain d'intérêt auprès des motoristes. En effet, ces modèles, fournissant aisément un comportement thermodynamique du moteur, peuvent être couplés avec des outils de contrôle moteur. Néanmoins, leur précision doit être augmentée, pour répondre aux enjeux technologiques actuels. Dans les moteurs à allumage commandé, la flamme turbulente prémélangée est modélisée comme un ensemble de flammelettes cohérentes entre elles. Cette approche généraliste nécessite un traitement particulier en proche paroi, motivé par une modification de la structure de flamme due aux couches limites thermique et cinématique. Ce présent travail propose des approches de modélisations 0D de la combustion, en proche paroi et dans la zone réactionnelle de la flamme. Pour modéliser la combustion en proche paroi, la flamme est scindée en une contribution en propagation libre, et une contribution en interaction avec les parois. Chaque contribution est divisée en une zone de transport, dans laquelle l'entraînement des gaz frais est décrit, et une zone de réaction, dans laquelle la réaction de combustion est modélisée. L'ajout d'une zone de réaction en interaction avec les parois permet de modéliser un gradient de température et une réaction de combustion ralentie en proche paroi. Pour modéliser la zone réactionnelle, une discrétisation de la flamme en N zones de réaction indépendantes est proposée. Une plage de fonctionnement moteur a été simulée avec nos approches de modélisation, afin de quantifier la variabilité des paramètres de calibration. Pour ce faire, les modèles sont calibrés sur chaque point de fonctionnement, par une méthode de minimisation de l'erreur quadratique moyenne sur la loi de dégagement d'énergie. Des corrélations aisées de paramètres de calibration peuvent être établies, en fonction de paramètres moteurs. Les résultats de simulations, obtenus à partir de ces corrélations, sont satisfaisants. / Recently, the interest for zero-dimensional models has increased. Indeed, these models provide easily the engines thermodynamic behavior and can be coupled with control tools. However, their accuracy must be improved to meet the current technological challenges. In the spark ignition engines, the premixed turbulent flame is modeled as a set of coherent flamelets. This approach requires special treatment near the walls, motivated by the modifications of the flame structure due to boundary layers. The present work proposes 0D modeling of combustion near the walls and in the reaction zone of the flame. To combustion model near the walls, the flame is divided into a free propagation contribution, and an interacting contribution with the walls. Each contribution is divided into a convective zone, wherein the entrainment of fresh gas is described, and a reaction zone, wherein the combustion reaction is modeled. Adding a reaction zone near the walls allows modeling a thermal gradient and a slower combustion reaction near the walls. To model the reaction zone, a flame discretization is made into several reaction zones. An engine operating range is simulated with our models, for quantifying the calibration parameters variability. To do this, models are calibrated on each operating point, by a method of minimization of the quadratic error on the heat released rate. Linear correlations can be found, depending on engines parameters. A good agreement between experimental data and simulation results is obtained with these parameters correlations.

Dans la première partie de cette thèse, je présenterai le 5D MSSM qui est un modèle super symétrique avec une dimension supplémentaire. (Five Dimensional Minimal Supersymmetric Standard Model). Apres compactification sur l'orbifold S1/Z2, le calcul des équations du groupe de renormalisation (RGE) à une boucle montre un changement dans l'évolution des paramètres phénoménologiques. Dès que l'énergie E = 1/R est atteinte, les états de Kaluza- Klein interviennent et donnent des contributions importantes. Plusieurs possibilités pour les champs de matière sont discutés : ils peuvent se propager dans le "bulk" ou ils sont localisés sur la "brane". Je présenterai d'une part l'évolution des équations de Yukawa dans le secteur des quarks ainsi que les paramètres de la matrice CKM, d'autre part, les effets de ce modèle sur le secteur des neutrinos notamment les masses, les angles de mélange, les phases de Majorana et de Dirac. Dans la deuxième partie, je parlerai du modèle AMSB et ses extensions (MM-AMSB et HCAMSB). Ces modèles sont des scenarios de brisure assez bien motivés en super symétrie. En calculant des observables issues de la physique des particules puis en imposant des contraintes de cosmologie standard et alternative sur ces scénarios, j'ai déterminé les régions qui respectent les contraintes de la matière noire et les limites de la physique des saveurs. Je reprendrai ensuite l'analyse de ces modèles en utilisant de nouvelles limites pour les observables. La nouvelle analyse est faite en ajoutant les mesures récentes sur la masse du Higgs et les rapports de branchement pour plusieurs canaux de désintégrations / In the first part of this thesis, we review the Universal Extra-Dimensional Model compactified on a S1/Z2 orbifold, and the renormalisation group evolution of quark and lepton masses, mixing angles and phases both in the UED extension of the Standard Model and of the Minimal Supersymmetric Standard Model (the five-dimensional MSSM). We consider two typical scenarios: all matter fields propagating in the bulk, and matter fields constrained on the brane. The two possibilities give rise to quite different behaviours. For the quark sector we study the Yukawa couplings and various flavor observables and for the neutrino sector, we study the evolution of neutrino masses, mixing angles and phases. The analysis is performed in the two cases for different values of tan β and different radii of compactification. The resulting renormalization group evolution equations in these scenarios are compared with the existing results in the literature, together with their implications. In the second part, we present a simulation study about anomaly mediated supersymmetry breaking and its extensions. Anomaly mediation is a popular and well motivated supersymmetry breaking scenario. Different possible detailed realisations of this set-up are studied and actively searched for at colliders. Apart from limits coming from flavour, low energy physics and direct collider searches, these models are usually constrained by the requirement of reproducing the observations on dark matter density in the universe. We reanalyse these bounds and in particular we focus on the dark matter bounds both considering the standard cosmological model and alternative cosmological scenarios. We briefly discuss the implications for phenomenology and in particular at the Large Hadron Collider. After that we update our analysis by using new limits from observables and adding recent Higgs boson measurements for the mass and signal strengths in different decay channels

The diploma thesis is focused on a quantification of hydrodynamic load of overflowed bridge deck. Solution was pursued by using two–dimensional numerical simulation of open channel flow in vertical plane created in ANSYS 15.0 software (modules: Workbench, Design Modeler, Meshing, Fluent). Values of drag force, lift force, moment, drag coefficient, lift coefficient and moment coefficient is result of computation. Various types of bridge decks were tested in relation to the degree of inundation (inundation ratio) and flow velocity.The thesis provides comparison of numerical simulation with physical experimental testing and result published in accessible resources.

This thesis presents the theme of low political awareness of adult citizens in the Czech Republic from the perspective of public policy. Low level of political awareness is conceived as a major reason that voters are not able to vote according to their real interests. The focus is on whether the problem is a topic that public policy should pursue and whether it is possible to find a public policy tools to deal with it. It is mainly based on the three-dimensional model of political sophistication, Evert Vedung's concept of public policy instruments, the concept of the correct voting and ideas of participatory democracy. Despite the fact that the given issue bears the hallmarks of an ideal problem for public policy and we can find some tools that could improve the current situation, there are broader factors that hinder their operations. These include the impact of previous undemocratic regime or the behavior of politicians. Such barriers are closely related to the way of human thinking and can be removed only with difficulty.

Bakgrund Bakgrunden till arbetet grundar sig i att ledarskap är ett komplext ämne som kan definieras på flera olika sätt. I det här arbetet bryter vi ner definitionen av ledarskap och utgår från tre ledarskapsstilar. Ledarskap är ett relevant och viktigt fenomen att studera då det återfinns överallt i samhället och kan skapa en känsla av sammanhang. Det finns också risker med ledarskap som kan leda till minskad arbetstillfredsställelse, fel beslut eller att organisationen tappar konkurrensfördelar. Syfte I denna studie undersöks ledarskapet genom tre-dimensionsmodellen som omfattas av relationsorienterat, uppgiftsorienterat samt förändrings- och utvecklingsorienterat ledarskap. Syftet med studien är att undersöka samt analysera ledarskapet genom både tre-dimensionsmodellen och en 360 graders utvärdering för att därigenom belysa aspekter av ledarskapet samt skapa förutsättningar till utveckling inom ledarskapet. Detta genom attkombinera tre-dimensionsmodellen med en 360 graders utvärdering som innebär att den aktuella ledaren får återkoppling både horisontellt och vertikalt. Metod Arbetet bygger på kvalitativ metod i form av semi-strukturerade intervjuer. Det genomfördes totalt nio intervjuer. De nio intervjupersoner som deltog i studien var den aktuella ledare, ledarens chef, två kollegor och fem medarbetare. Slutsats Studien undersöker en ledare inom en organisation i syfte att belysa delar som appliceras inom ledarskapet. Men även för att fånga upp och lyfta fram utvecklingsmöjligheter för organisationen och den aktuella ledaren. Studien kan användas som vägledning för att öka kompetensen kring ledarskap. Studien visar att en 360 graders utvärdering kan skapa förutsättningar för utveckling inom ledarskapet. Genom en 360 graders utvärdering etablerasen bild av ledaren från flera perspektiv vilket bidar till att skapa en bild och lägga ett pussel som visar ledarens egenskaper utifrån fler perspektiv i syfte att lyfta fram utvecklingsmöjligheter hos den aktuella ledaren. / Background Leadership is a complex subject that requires several definitions. In this study, we will break down the definition of leadership into three different styles. The subject of leadership is a relevant and important topic to study due to its prevalence in society, and its ability to create a context. There are also risks surrounding the leadership role which may lead to a decreased satisfaction at work, making wrong decisions, or loosing competitive advantages. Purpose In this study, the subject of leadership is examined through the three-dimensional model, which consists of relationship-oriented, task-oriented, and change- and development-oriented leadership. The purpose of this study is to examine and analyze leadership through the three-dimensional model and a 360-degree appraisal feedback process and highlight the leadership aspect, in order to create conditions for leadership development. By combining the two methods, the leader will receive feedback both horizontally and vertically. Method This study is based on a qualitative method in the shape of semi-structured interviews. A total of nine interviews were conducted. The people who were interviewed were: a leader, the boss of a leader, two colleagues of a leader as well as five employees of a leader.  Conclusion This study examines the role of a leader within an organization with the aim of highlighting leadership applications and to highlight opportunities for development, both for the organization and the leader. This study can be used as a guide in order to increase knowledge around the subject of leadership. The study shows that the application of a 360-degree appraisal feedback process can create conditions for development within leadership. By using this survey, we will look at the role of the leader from several perspectives in order to highlight development opportunities within the leadership.

No description available.

Syftet med studien i föreliggande uppsats är att pröva hur dimensionella modellen kan bedöma de avsikter skolchefen formulerar för att förbättra fritidshemmets undervisning, för att, i ett nästa steg, bidra i det systematiska kvalitetsarbetet.  Frågeställningen undersöker på vilket sätt den dimensionella modellens kvalitativa bedömningskriterier kan bidra, dels med kvalitativa bedömningar av skolchefens avsikter att förbättra fritidshemmets undervisning, dels fungera som underlag att generera formativa frågor för kommande systematiska kvalitetsarbete.  Denna kvalitativa, deduktiva studie använder systemteori som utgångspunkt. Teorin utgår från tanken att skolors likaväl som skolsystems kultur och historia ser olika ut, varför insatser behöver differentieras för att motsvara skolans uppdrag. System avser i det här fallet helheter, bildade av individer och organisationer.  Medvetenhet om detta gör det lättare att orientera sig i skolans komplexa verksamhet och det blir möjligt att förändra och därmed förbättra.  Empiriskt material inhämtades ur grundskolors huvudmannaplaner. Resultatet visar en bild där fritidshemmet är relativt osynligt, särskilt gällande utbildningsuppdraget. Skolchefens avsikter likaså. Dimensionella modellen bidrog till bilden genom att belysa centrala dimensioner i planerna samt med underlag för formativa frågor. Slutsatsen är att planerna har ett stort utrymme till förbättring, utifrån samtliga dimensionerna. I utrymmet framträder frågor att använda formativt för att förbättra måluppfyllelsen i fritidshemmet. / The aim is to test how The Dimensional model can assess the intentions formulated by the Superintendent to improve teaching in the LtCs, to, in the following, contribute to the systematic quality work.   The question examines how The Dimensional model's qualitative assessment criteria can con-tribute, partly with qualitative assessments of the Superintendents' intentions to improve teaching in the LtCs and partly serve as a basis for generating Formative questions for future Systematic quality Development Work.   This qualitative, deductive study uses Systems Theory as starting point. The theory is based on the idea that schools as well as school systems look different in terms of culture and history, which is why efforts need to be differentiated to meet the purpose. Here, systems are wholes, formed by individuals and organizations. Awareness of this makes it easier to orientate oneself in complex activities in schools and it becomes possible to change and thus also improve.   Data was gathered from Plans of the Schoolboard for the compulsory school.   The results draw a picture of the LtCs being relatively undetectable. That is also true for the aims of the Superintendent. The Dimensional model added to the picture by illustrating core dimensions in the Plans and well as Formative questions.    The conclusion is that the Plans have a lot of room for improvement. In that gap, questions emerge to use formatively to improve the fulfillment of goals in the LtCs.