Les pompes à induction linéaires électromagnétiques (PEM) sont un sujet de recherche important dans le développement des réacteurs rapides refroidis au sodium de génération IV. En particulier, dans le cadre du programme de simulation numérique R&D du Commissariat à l’énergie atomique et aux énergies alternatives (CEA), la prédiction du comportement des pompes à induction linéaires annulaires (ALIP) a été évaluée en raison de ses avantages en termes de sécurité par rapport aux pompes mécaniques.Pour des raisons de sûreté nucléaire, il est nécessaire de connaître le comportement d'une ALIP dans des conditions hors conception. En conséquence, le présent travail se concentre sur l’étude de la phénoménologie magnétohydrodynamique (MHD) et de ses instabilités, ces dernières se produisant lors du passage d’une branche linéaire à une branche non linéaire de la courbe de performance au maximum de pression. Ce phénomène est associé à une diminution conséquente de la pression et du rendement développés par la pompe et intervient dans des régimes de fonctionnement à grand nombre de Reynolds magnétiques (RmB), lequel quantifie la relation convection-diffusion du champ magnétique.Cette recherche vise à développer différents outils permettant de décrire des phénomènes et de prévoir des comportements pour différents régimes de performance. Ce raisonnement a été construit selon trois axes principaux basés sur les recherches bibliographiques plus notables sur le sujet. Ils consistent en i) la caractérisation des principaux effets déclenchés lors de l'opération de l’ALIP à l'aide d'approches théoriques et l'obtention de seuils de stabilité à partir desquels l’écoulement MHD pourrait devenir instable, ii) la mise au point de modèles numériques précis capables de reproduire les comportements physiques proches de ceux des installations réelles et iii) l'observation et l'analyse de phénomènes utilisant différentes méthodes pour le post-traitement de données volumineuses acquises par l'exploitation de l'installation expérimentale PEMDyn, située au centre du CEA Cadarache.Dans ces travaux, la comparaison des résultats obtenus à travers ces trois approches différentes a permis de décrire les instabilités MHD attendues lors de l’opération à grand nombre de Reynolds magnétique de glissement (Rms). Ils sont caractérisés par des pulsations à basse fréquence (LF), des inhomogénéités de vitesse et de champ magnétique, des vibrations, etc. On a obtenu ici que ces phénomènes pourraient être dus à une amplification des perturbations à l'entrée, déclenchée par une certaine valeur de la vitesse de glissement. Cette amplification peut être quantifiée avec des modèles théoriques ou numériques et a été observée lors d'expériences.En outre, cette étude met l'accent sur le niveau de détail requis dans les modèles analytiques et numériques en fonction de leur portée. Un nombre important de modèles avec différentes exactitudes et hypothèses ont donc été développés. Une des conclusions principales extraites montre l’importance des effets de bouts dus à la longueur finie de l’inducteur sur les performances et la stabilité des ALIPs. / Electromagnetic Linear Induction Pumps (EMPs) are an important research subject in the development of Gen IV sodium-cooled fast reactors. Especially, in the framework of the French Alternative Energies and Atomic Energy Commission’s (CEA) R&D numerical simulation program, the prediction of the behavior of Annular Linear Induction Pumps (ALIPs) is been evaluated because of its safety advantages compared to mechanical pumps.For nuclear safety reasons, it is needed to know the behavior of an ALIP at off-design conditions. Consequently, the present work is focused on the study of magnetohydrodynamic (MHD) phenomenology and instabilities, these last occurring at the transition from linear to non-linear branch of the performance curve at the maximum of pressure. This phenomenon is associated to a consequent decrease of the pump developed pressure and efficiency and takes place at large magnetic Reynolds number (RmB), which quantifies the relation convection to diffusion of the magnetic field.This research aims to develop different tools permitting to describe phenomena and predict behavior for different performance regimes. This reasoning has been constructed following three main axes based on bibliographic researches on the subject. They consist of i) the characterization of main effects triggered during the performance of ALIPs using theoretical approaches and obtaining of stability thresholds from which the MHD flow might become unstable, ii) the development of accurate numerical models able to reproduce physical behavior close to real facilities and iii) the observation and analysis of phenomena using different methods for the post-treatment of big data acquired through the exploitation of the experimental facility PEMDyn, located in CEA Cadarache, France.In this work, the comparison of obtained results through these three different approaches has permitted to describe the MHD instabilities expected at operations with high values of slip magnetic Reynolds number (Rms). They are characterized by low frequency (LF) pulsations, velocity and magnetic field inhomogeneities, vibrations, etc. Here it has been obtained that these phenomena might be due to an amplification of inlet perturbations, triggered by the value of the slip velocity. Such amplification may be quantified with theoretical or numerical models, and has been observed on experiments.Furthermore, the current study puts the accent on the required level of detail in analytical and numerical models depending on their scope, and thus, an important number of models with different accuracies and assumptions has been developed. One of main conclusions extracted shows the importance of end effects due to the finite length of the inductor on the performance and stability of ALIPs.

O objetivo deste trabalho é a análise dos elementos de cortesia e atenuação no Português falado na região de São José do Rio Preto e no Espanhol falado na região de Málaga. Os corpora analisados foram obtidos por meio de entrevistas semidirigidas e fazem parte do Projeto ALIP Amostra Linguística do Interior Paulista, o brasileiro, e PRESEEA - Proyecto para el Estudio Sociolingüístico del Español de España y América, o espanhol. Analisamos um total de 24 entrevistas, sendo 12 de nível médio e 12 de superior, seis em cada idioma, divididas igualmente entre falantes do sexo feminino e do sexo masculino. Os falantes de nível médio tinham idades entre 25 e 45 anos, enquanto que a faixa etária entre os de nível superior era entre 50 e 70 anos. Partindo da teoria pragmática dos Atos de Fala e de estudos mais recentes sobre cortesia e atenuação de teóricos como Leech (2007), Bravo (2001, 2004, 2005), Kerbrat-Orecchioni (2004, 2005, 2006), entre outros, analisamos tanto a fala dos entrevistadores quanto a dos informantes. A partir da fala dos entrevistadores, pudemos observar como as perguntas, as solicitações de informações eram elaboradas em ambos os idiomas. Tal análise possibilitou a verificação de como o entrevistador se posicionava e quais eram as estratégias utilizadas verbos no imperativo, enunciados diretos, uso de atos de preparação ou verbos que visavam a proteger a face do informante. Já a análise da fala dos informantes objetivou a averiguação do uso de outras estratégias, cuja intenção era a defesa pessoal ou de terceiros, protegendo sua própria face ou a do entrevistador. Entre essas estratégias citamos a desfocalização do eu, a proteção à própria face ou à do outro, o uso de elementos atenuadores no momento de expressar opiniões, entre outras. Ao longo de nossa análise investigamos também o posicionamento de cada entrevista no eixo de solidariedade ou poder de acordo com a teoria de Brown e Gilman (1960). Para isso, foi necessário o estudo das formas de tratamento empregadas, bem como o uso ou não de formas nominais. Os resultados obtidos, dentro dos corpora estudados, mostram que a Língua Espanhola é uma língua de mais aproximação com o interlocutor, enquanto que a Língua Portuguesa denota maior distância. Observou-se ainda que determinados elementos como o uso de um tratamento mais formal no caso da Língua Portuguesa se caracteriza mais como uma estratégia conversacional do que uma distância social. / The present paper aims at the analysis of the politeness and attenuation elements in both the Portuguese spoken in São José do Rio Preto region and in the Spanish spoken in Malaga region. The studied corpora were obtained by means of partially guided interviews and are part of the ALIP Project (São Paulo\'s Countryside Linguistic Sampling), the Brazilian one, and the PRESEEA ( Project for the Sociolinguistic Study of the Spanish Spoken in Spain and America), the Spanish one. A total of 24 interviews were analysed, being 12 of those on an average level and the other 12 on a superior one, six in each language, equally divided into male and female speakers. The average level speakers range aged from 25 to 45 whereas the superior level ranged from 50 to 70. Considering the pragmatic theory of Speech Acts and other more recent studies on politeness and attenuation by theorists such as Leech (2007), Bravo (2001, 2004, 2005), Kerbrat-Orecchioni (2004, 2005, 2006), among others, both interviewers\' and interviewees\' speeches were analysed. From the interviewers\' speeches it was possible to observe how the questions, the information required, were built up in both languages. Such an analysis made possible verifying how the interviewer was positioned as well as which strategies were used: verbs in imperative, direct enunciations, preparation acts usage or verbs aiming at protecting the informer\'s face. Yet the informers\' speech analysis aimed at the inquiry of other strategies usage being the intention of such the personal or third parties\' defense, proctecting oneself\'s face or the interviewer\'s one. Among these strategies we mention defocusing the self, protecting oneself\'s own face or the other\'s one, attenuating elements usage when expressing opinions, among others. Throughout our analysis we investigated also the positioning of each interview coming to the axis solidarity or power according to Brown and Gilman\'s theory (1960). For such, it was made necessary the study of the treatment forms applied as well as the use or not of noun forms. The achieved results in the studied corpora showed that the Spanish language proves to be a language of more approximation coming to the interlocutor whereas the Portuguese language denotes more distance. It could also be noticed that certain elements such as the use of a more formal treatment coming to the Portuguese language are characterized more as a conversational strategy than as a social distance element.

O objetivo deste trabalho é a análise dos elementos de cortesia e atenuação no Português falado na região de São José do Rio Preto e no Espanhol falado na região de Málaga. Os corpora analisados foram obtidos por meio de entrevistas semidirigidas e fazem parte do Projeto ALIP Amostra Linguística do Interior Paulista, o brasileiro, e PRESEEA - Proyecto para el Estudio Sociolingüístico del Español de España y América, o espanhol. Analisamos um total de 24 entrevistas, sendo 12 de nível médio e 12 de superior, seis em cada idioma, divididas igualmente entre falantes do sexo feminino e do sexo masculino. Os falantes de nível médio tinham idades entre 25 e 45 anos, enquanto que a faixa etária entre os de nível superior era entre 50 e 70 anos. Partindo da teoria pragmática dos Atos de Fala e de estudos mais recentes sobre cortesia e atenuação de teóricos como Leech (2007), Bravo (2001, 2004, 2005), Kerbrat-Orecchioni (2004, 2005, 2006), entre outros, analisamos tanto a fala dos entrevistadores quanto a dos informantes. A partir da fala dos entrevistadores, pudemos observar como as perguntas, as solicitações de informações eram elaboradas em ambos os idiomas. Tal análise possibilitou a verificação de como o entrevistador se posicionava e quais eram as estratégias utilizadas verbos no imperativo, enunciados diretos, uso de atos de preparação ou verbos que visavam a proteger a face do informante. Já a análise da fala dos informantes objetivou a averiguação do uso de outras estratégias, cuja intenção era a defesa pessoal ou de terceiros, protegendo sua própria face ou a do entrevistador. Entre essas estratégias citamos a desfocalização do eu, a proteção à própria face ou à do outro, o uso de elementos atenuadores no momento de expressar opiniões, entre outras. Ao longo de nossa análise investigamos também o posicionamento de cada entrevista no eixo de solidariedade ou poder de acordo com a teoria de Brown e Gilman (1960). Para isso, foi necessário o estudo das formas de tratamento empregadas, bem como o uso ou não de formas nominais. Os resultados obtidos, dentro dos corpora estudados, mostram que a Língua Espanhola é uma língua de mais aproximação com o interlocutor, enquanto que a Língua Portuguesa denota maior distância. Observou-se ainda que determinados elementos como o uso de um tratamento mais formal no caso da Língua Portuguesa se caracteriza mais como uma estratégia conversacional do que uma distância social. / The present paper aims at the analysis of the politeness and attenuation elements in both the Portuguese spoken in São José do Rio Preto region and in the Spanish spoken in Malaga region. The studied corpora were obtained by means of partially guided interviews and are part of the ALIP Project (São Paulo\'s Countryside Linguistic Sampling), the Brazilian one, and the PRESEEA ( Project for the Sociolinguistic Study of the Spanish Spoken in Spain and America), the Spanish one. A total of 24 interviews were analysed, being 12 of those on an average level and the other 12 on a superior one, six in each language, equally divided into male and female speakers. The average level speakers range aged from 25 to 45 whereas the superior level ranged from 50 to 70. Considering the pragmatic theory of Speech Acts and other more recent studies on politeness and attenuation by theorists such as Leech (2007), Bravo (2001, 2004, 2005), Kerbrat-Orecchioni (2004, 2005, 2006), among others, both interviewers\' and interviewees\' speeches were analysed. From the interviewers\' speeches it was possible to observe how the questions, the information required, were built up in both languages. Such an analysis made possible verifying how the interviewer was positioned as well as which strategies were used: verbs in imperative, direct enunciations, preparation acts usage or verbs aiming at protecting the informer\'s face. Yet the informers\' speech analysis aimed at the inquiry of other strategies usage being the intention of such the personal or third parties\' defense, proctecting oneself\'s face or the interviewer\'s one. Among these strategies we mention defocusing the self, protecting oneself\'s own face or the other\'s one, attenuating elements usage when expressing opinions, among others. Throughout our analysis we investigated also the positioning of each interview coming to the axis solidarity or power according to Brown and Gilman\'s theory (1960). For such, it was made necessary the study of the treatment forms applied as well as the use or not of noun forms. The achieved results in the studied corpora showed that the Spanish language proves to be a language of more approximation coming to the interlocutor whereas the Portuguese language denotes more distance. It could also be noticed that certain elements such as the use of a more formal treatment coming to the Portuguese language are characterized more as a conversational strategy than as a social distance element.