Simulação computacional da interação fluido-estrutura em bombas de cavidades progressivas

The pumping through progressing cavities system has been more and more employed in the petroleum industry. This occurs because of its capacity of elevation of highly viscous oils or fluids with great concentration of sand or other solid particles. A Progressing Cavity Pump (PCP) consists, basically, of a rotor - a metallic device similar to an eccentric screw, and a stator - a steel tube internally covered by a double helix, which may be rigid or deformable/elastomeric. In general, it is submitted to a combination of well pressure with the pressure generated by the pumping process itself. In elastomeric PCPs, this combined effort compresses the stator and generates, or enlarges, the clearance existing between the rotor and the stator, thus reducing the closing effect between their cavities. Such opening of the sealing region produces what is known as fluid slip or slippage, reducing the efficiency of the PCP pumping system. Therefore, this research aims to develop a transient three-dimensional computational model that, based on single-lobe PCP kinematics, is able to simulate the fluid-structure interaction that occurs in the interior of metallic and elastomeric PCPs. The main goal is to evaluate the dynamic characteristics of PCP s efficiency based on detailed and instantaneous information of velocity, pressure and deformation fields in their interior. To reach these goals (development and use of the model), it was also necessary the development of a methodology for generation of dynamic, mobile and deformable, computational meshes representing fluid and structural regions of a PCP. This additional intermediary step has been characterized as the biggest challenge for the elaboration and running of the computational model due to the complex kinematic and critical geometry of this type of pump (different helix angles between rotor and stator as well as large length scale aspect ratios). The processes of dynamic generation of meshes and of simultaneous evaluation of the deformations suffered by the elastomer are fulfilled through subroutines written in Fortan 90 language that dynamically interact with the CFX/ANSYS fluid dynamic software. Since a structural elastic linear model is employed to evaluate elastomer deformations, it is not necessary to use any CAE package for structural analysis. However, an initial proposal for dynamic simulation using hyperelastic models through ANSYS software is also presented in this research. Validation of the results produced with the present methodology (mesh generation, flow simulation in metallic PCPs and simulation of fluid-structure interaction in elastomeric PCPs) is obtained through comparison with experimental results reported by the literature. It is expected that the development and application of such a computational model may provide better details of the dynamics of the flow within metallic and elastomeric PCPs, so that better control systems may be implemented in the artificial elevation area by PCP

Simulação do escoamento multifásico no interior de bombas de cavidades progressivas metálicas

The progressing cavity pumping (PCP) is one of the most applied oil lift methods nowadays in oil extraction due to its ability to pump heavy and high gas fraction flows. The computational modeling of PCPs appears as a tool to help experiments with the pump and therefore, obtain precisely the pump operational variables, contributing to pump s project and field operation otimization in the respectively situation. A computational model for multiphase flow inside a metallic stator PCP which consider the relative motion between rotor and stator was developed in the present work. In such model, the gas-liquid bubbly flow pattern was considered, which is a very common situation in practice. The Eulerian-Eulerian approach, considering the homogeneous and inhomogeneous models, was employed and gas was treated taking into account an ideal gas state. The effects of the different gas volume fractions in pump volumetric eficiency, pressure distribution, power, slippage flow rate and volumetric flow rate were analyzed. The results shown that the developed model is capable of reproducing pump dynamic behaviour under the multiphase flow conditions early performed in experimental works

Avaliação da aplicação de modelos para a secagem de pastas e suspensões em leito de jorro com alimentação contínua

This work studies the development, implementation and improvement of a macroscopic model to describe the behavior of the spouted bed dryer with continuous feeding for pastes and suspensions drying. This model is based on the CST model (Freire et al., 2009) and the model of Fernandes (2005), whose theoretical foundation is based on macroscopic mass and heat balances for the three phases involved in the process: gas, liquid and solid. Because this technique is quite relevant, the studies of modeling and simulation of spouted bed drying are essential in the analysis of the process as a whole, because through them it is possible to predict and understand the behavior of the process, which contributes significantly to more efficient project and operation. The development and understanding of the phenomena involved in the drying process can be obtained by comparing the experimental data with those from computer simulations. Such knowledge is critical for choosing properly the process conditions in order to obtain a good drying efficiency. Over the past few years, researches and development of works in the field of pastes and suspensions drying in spouted bed has been gaining ground in Brazil. The Particulate Systems Laboratory at Universidade Federal do Rio Grande do Norte, has been developing several researches and generating a huge collection of experimental data concerning the drying of fruit pulps, vegetables pastes, goat milk and suspensions of agro-industrial residues. From this collection, some data of goat milk and residue from acerola (Malpighia glabra L.) drying were collected. For the first time, these data were used for the development and validation of a model that can describe the behavior of spouted bed dryer. Thus, it was possible to model the dryer and to evaluate the influence of process variables (paste feeding, temperature and flow rate of the drying air) in the drying dynamics. We also performed water evaporation experiments in order to understand and to study the behavior of the dryer wall temperature and the evaporation rate. All these analysis will contribute to future works involving the implementation of control strategies in the pastes and suspensions drying. The results obtained in transient analysis were compared with experimental data indicating that this model well represents the process

Modelagem e simulação da solubilização da parafina em tubos circulares e em regime laminar

O óleo produzido nos novos campos de petróleo está cada vez mais parafínico e viscoso, com isso, à medida que o óleo é escoado, parafinas são depositadas sobre as paredes internas do tubo, e ao longo do tempo, tendem a reduzir drasticamente a área transversal ao escoamento. Visando estudar o processo de solubilização da parafina em dutos, esse trabalho objetiva desenvolver modelos matemáticos que represente o processo, com base nos fenômenos envolvidos no mesmo tais como transferência de massa, transferência de energia e equilíbrio sólido-líquido, implementando-os em um ambiente de desenvolvimento VBA (Visual Basic) for Excel ®. O presente trabalho foi realizado em quatro etapas: i) modelagem dos fenômenos de transferência de calor e massa, ii) modelagem da rotina dos coeficientes de atividade através do modelo UNIFAC e modelagem do sistema de equilíbrio sólido-líquido; iii) modelagem matemática do processo de solubilização e cálculo da espessura da parafina ao longo do tempo; iv) implementação dos modelos em um ambiente de desenvolvimento VBA for Excel® e criação de um simulador com uma interface gráfica, para simular o processo de solubilização da parafina depositada em dutos e sua otimização. O simulador conseguiu produzir soluções bastante adequadas, mantendo continuidade das equações diferenciáveis do balanço de energia e de massa, com uma interpretação física viável, sem a presença de dissipação de oscilações nos perfis de temperatura e massa. Além disso, esse simulador visa permitir a simulação nas diversas condições de escoamento, bem como compreender a importância das variáveis (vazão, temperatura de entrada, temperatura externa, cadeia carbônica do solvente). Através dos resultados foram possíveis verificar os perfis de temperatura, fração molar e o de solubilização

Estudo da circulação hidrodinâmica e da dispersão de óleo na zona costeira entre Macau e Galinhos RN

This paper presents a study on coastal hydrodynamics and the spread of an oil spill in waters off Macau and Galinhos, on the east coast of the state of Rio Grande do Norte in Northeast Brazil. This area has a very marked coastal dynamic owing to the complexity of its geomorphological features, developed in a regime of semidiurnal mesotides involving reefs, spits, estuaries, mangroves, lakes and dunes. The region also plays an important role in the socioeconomic development of the state, given that the production of oil, natural gas, salt and shrimp is concentrated there. The series of oil platforms is interconnected by a pipeline system that carries oil to the local terminal. This pipeline could leak at any moment, causing immense ecological damage. To gauge the risks of an oil leak and resulting contamination of the coastal region, two hydrodynamic scenarios were simulated. The results obtained were used to implement a contaminant transport model with the creation of various oil leak scenarios modeled at different volumes (from small to large) and intensities (sporadic and continuous), at points considered critical for the model (on two platforms and at two pipeline intersections), under different wind (summer and winter) and tidal (high and low at new, full and quarter moon phases) conditions. The use of hydrodynamic circulation computer models as a tool for representing a real project design has been increasingly frequent in recent years, given that they enable the realistic simulation of the hydrodynamic circulation pattern in bodies of water and an analysis of the impacts caused by contaminants released into the water. This study used the computer models contained in SisBAHIA®, in continuous development in the area of Coastal Engineering and Oceanography at COPPE/UFRJ

Construções metafóricas de vida e morte: cognição, cultura e linguagem

En esta investigación, tratamos de poner de relieve los aspectos cognitivos y culturales que subyacen a las metáforas en el lenguaje. Partimos de la premisa de que nuestra comprensión a cerca del mundo se construye socio-cognitivamente, sendo la metáfora un elemento clave de esta construcción. Por lo tanto, tenemos la intención de mirar debajo de la teoría de la Teoría Cognitiva de la Metáfora, visto desde el análisis del poema Morte e Vida Severina, de João Cabral de Melo Neto, la metáfora de la vida y muerte, inferíveis en el corpus forma patrones discursivos, llamado por nosotros como el Construccionismo del Bloques. Estas metáforas se encuentran en el nivel conceptual de nuestro lenguaje, emitido por modelos cognitivos idealizados, y mostrar las relaciones entre la lengua, la cultura y la cognición. Vemos una red de integración que implica la metáfora primaria llamada, elaborado a partir de los esquemas y los dominios conceptuales y metáforas congruentes, con la participación de la noción de marco.

O imaginário da mediunidade no processo de escritura em Fernando Pessoa

The answer to creating a fictional world? Repulsion or form of reaction to an outside world? Mental illness, whose brand can be symbolic simulation or depersonalization? Hard to take a stand when the deed is a poet Fernando Pessoa as what is at stake. Notes Schlafman Léo (1998) who, at the age of 20 years, Fernando Pessoa wrote in English, in his diary, "One of my mental complications is the fear of madness, which in itself already is crazy." What rid of madness, notes Robert Bréchon (1986), was the taste of the game and was playing it for your writing. Even though it has rid the madness, the poet does not quit seeking explanations - or provide it - for the phenomena much bother him, or defined.'s where we come across the alignment of Fernando Pessoa within philosophical as occultism and reading about psychological and mental disorders treated. paths were pursued by him to explain the existence of his heteronyms and its entry process. This work therefore presents main objective: to analyze the personal papers of Fernando Pessoa, whose outstanding feature is the presence of occult and alleged mediumship demonstrations held in response to non-literary and heteronímicas. Therefore, I focused on specific goals, which are: a) to study the speech of Fernando Pessoa on his mediumship / occult b) analyzing specific texts that are, for the poet, psychic demonstrations, c) study of a series of excerpts personal letters in which Fernando Pessoa suggested to be a medium. Admittedly, this essay will touch many arguments already made by scholars and experts of Fernando Pessoa, but consider the possibility of developing issues and contribute to the critical fortune of the poet. We assume that announces the Portuguese scholar Jerome Pizarro (2006), one of the greatest scholars of the work Pessoan: those interested in Fernando Pessoa be lost in the maze created by him. It is the image of a person-Minotaur, devouring all but, holding us in its labyrinthine tessitura, as marked by mystery. Will draw on our analysis, a theory aligned themselves to objects of research, whose main authors are Sigmund Freud (1908) Carl Jung (1991.1996). Gaston Bachelard (1996), Helena Blavatsky (2008), among others

Estratégias de relativização no português brasileiro e implicações para o ensino: o caso das cortadoras

This work consists of a cognitive-functional approach of relativization strategies of Brazilian Portuguese (BP), this is, standard relatives (with preposition or without it) and non-standard relatives (copiadora and the deletion pattern), and it emphasizes the last one. We investigate the use of the relative construction strategies in spoken and written texts produced by speakers from different school levels in a specific situation: a face-to-face interviewing. Our database is the corpora Discurso & Gramática: a língua falada e escrita na cidade do Natal e a língua falada e escrita na cidade do Rio de Janeiro. We contrast the use of the standard relative to the deletion pattern in prepositional context, by considering cognitive, social and interactional motivations for the use of the deletion pattern instead of the standard one. Our research leads us to verify that the deletion pattern is fixing as the preferred relativization strategy in prepositional contexts, and, in this way, it brings out a grammaticalization process in working. For this reason, we propose to take this relative construction as a common way to structure a relative clause, in the same way we take the standard pattern. Finally, we discuss the treatment of questions related to the processes of teaching and learning of Portuguese language and some suggestions are given in terms of class activities. We expect that the development of this research may give both support for the Portuguese teachers and suggestions to improve the teaching and learning process of Portuguese language, contributing in special to the treatment of the syntax of complex clauses.

Modelos de realizações discursivas nos benditos populares e nas novenas

With the purpose of contribute to the understanding of oral texts constituent processes, we seek, with this work, verify how formulaicity processes in the benditos and novenas , religious intangible heritage, are established. For this, we made an overview on the performance of repetitions which are established in the corpus collected for the study, considering the presence of Discourse Traditions in the analyzed texts. It is noteworthy that the corpus consists of benditos and novenas collected in the municipality of Lajes, Rio Grande do Norte. This material is part of the differential corpus of the Project for the History of Brazilian Portuguese (PHPB-RN). Regarding the theoretical framework used to guide the research, we based our analysis on Discourse Traditions (DTs) theoretical assumptions, with the ideas defended by Johannes Kabatek, besides taking into consideration the assumptions of Paul Zumthor about orality in popular religious texts, among other authors cited throughout the work. In the context of popular cultures, the existence of oral texts serves to various interactive objects and this is not different in popular benditos and novenas (cf. Sá Júnior, 2009). In this sense, focusing the gaze through Discourse Traditions (DTs), we can verify that the texts/discourses present discursive regularities or textual forms already produced by society, in earlier times, which remain or are modified throughout its existence, as shows Johannes Kabatek (2001, 2003, 2005 and 2006). Also in this sense, Paul Zumthor (1993) presents us the idea that talk about using "word" in memory, in its real sense, implies admitting it as something which has an immeasurable power, which is able to decide directions in world, and from that is established the "wealth of oral traditions"

Representações discursivas de Ficar e Namorar em textos de vestibulandos e pré-vestibulandos

This doctoral thesis investigate the way vestibulandos and pré-vestibulandos construct their discursive representations of Ficar and Namorar in their textual production. At the same time, aims to discuss its implications for the ATD and for the teaching and learning of textual production in the context of Portuguese Language classes. Its theoretical framework is inspired mainly by three sources: textual linguistics, the textual analysis of discourses (ADAM, 2008), as well as by frames semantics (FILLMORE, 2006; FELTES, 2007). The methodology is based on a combination of qualitative and quantitative approaches (VIANNA et al., 2008). The data is composed of 168 empirical texts written by the vestibulandos of PSV/2005 da UFRN, Natal, RN, and by secondary school students who attended Escola Estadual Juscelino Kubitschek (EEJK), Assú, in the 2008 school year. The results indicate different categories of discursive representations of Ficar and Namorar , such as designation of referents, prediction, aspectualization, spatial-temporal circunstances , and metaphor, which reveal the influence of factors such as: the encyclopedic knowledge, the culture, as well as the cognitive components related to textual production. These results point out to the necessity of a teaching practice which enables the interaction among students, the discussion of current themes, as well as the student involvement with different textual genres, mainly the work with textual production in the classroom, so that it enables the students do acquire the textual production strategies. Thus, the overall goal is the (re)construction of their discursive representations, so that they can cope with new contexts of communicative interaction.

A interpretação semântica dos auxiliares modais poder, precisar e dever: uma abordagem da semântica cognitiva

Apresentamos, neste trabalho, com base na semântica cognitiva, uma análise do significado, em contexto, dos auxiliares modais poder, precisar e dever. Analisamos 120 textos produzidos por candidatos ao vestibular e por alunos do ensino fundamental, como resposta da questão número três da prova discursiva de Língua Portuguesa do vestibular 2005 da UFRN, que pede aos candidatos para explicitar a diferença de sentido entre três frases, observando o uso desses três verbos. Consideramos que um item lexical não é incorporado a uma representação lingüística semântica fixa, limitada e única, mas antes, é ligado a uma representação lingüística semântica flexível e aberta que provê acesso a muitas concepções e sistemas conceituais dependente de cada contexto determinado. Com base em seu significado, um item lexical evoca um grupo de domínios cognitivos, que por sua vez, apresentam um determinado conteúdo conceitual. Isto implica em afirmar que a rede de significados lexicais vai variar conforme o conhecimento de mundo de cada um (LANGACKER, 2000). A relevância deste trabalho é proporcionar uma contribuição para a descrição semântica do português

A argumentação como elemento discursivo na mídia digital: um estudo sobre o blog fatos e dados

This thesis studies the use of argumentation as a discursive element in digital media, particularly blogs. We analyzed the Blog "Fatos e Dados" [Facts and Data], created by Petrobras in the context of allegations of corruption that culminated in the installation of a Parliamentary Commission of Inquiry to investigate the company within the Congress. We intend to understand the influence that the discursive elements triggered by argumentation exercise in blogs and about themes scheduling. To this end, we work with notions of argumentation in dialogue with questions of language and discourse from the work of Charaudeau (2006), Citelli (2007), Perelman & Olbrechts-Tyteca (2005), Foucault (2007, 2008a), Bakhtin (2006) and Breton (2003). We also observe our subject from the perspective of social representations, where we seek to clarify concepts such as public image and the use of representations as argumentative elements, considering the work of Moscovici (2007). We also consider reflections about hypertext and the context of cyberculture, with authors such as Levy (1993, 1999, 2003), Castells (2003) and Chartier (1999 and 2002), and issues of discourse analysis, especially in Orlandi (1988, 1989, 1996 and 2001), as well as Foucault (2008b). We analyzed 118 posts published in the first 30 days of existence of the blog "Fatos e Dados" (between 2 June and 1 July 2009), and analyzed in detail the top ten. A corporate blog aims to defend the points of view and public image of the organization, and, therefore, uses elements of social representations to build their arguments. It goes beyond the blog, as the main news criteria, including the posts we reviewed, the credibility of Petrobras as the source of information. In the posts analyzed, the news values of innovation and relevance also arise. The controversy between the Blog and the press resulted from an inadequacy and lack of preparation of media to deal with a corporate blog that was able to explore the characteristics of liberation of the emission pole in cyberculture. The Blog is a discursive manifestation in a concrete historical situation, whose understanding and attribution of meaning takes place from the social relations between subjects that, most of the time, place themselves in discursive and ideological dispute between each other - this dispute also affects the movements of reading and reading production. We conclude that intersubjective relationships that occur in blogs change, in the form of argumentative techniques used, the notions of news criteria, interfering with scheduling of news and organization of information in digital media outlets. It is also clear the influence that the discursive elements triggered by argumentation exercise in digital media, trying to resize and reframe frames of reality conveyed by it in relation to the subject-readers. Blogs have become part of the scenario information with the emergence of the Internet and are able to interfere in a more effective way to organize the scheduling of media from the conscious utilization of argumentative elements in their posts

O jogo das identidades como fator de mobilização político-eleitoral nas campanhas de Dilma Rousseff e Rosalba Ciarlini em 2010

Starting from the premise that we live in the society of spectacle, as proclaimed by Guy Debbord, and, in this context, the media feeds itself off of this spectacularization and constructs a culture of images and production of goods, providing templates from which the subject can identify himself/herself as being male or female, successful or unsuccessful, powerful or powerless. In other words, the culture conveyed by the media produces material for the creation of identities through which individuals insert and recognize themselves in contemporary society. Observing the election campaigns, we can see clearly that this profusion of identities is fairly explored in the advertising propaganda used by the candidates, particularly in the propaganda broadcasted on the Free Electoral Time on TV. Instigated by the explicit relation between the media and politics within the society of the spectacle, this study aims to investigate the main identities that emerge in the discursive practices of the media in the election campaigns of 2010 for president of the Republic and governor of the State of Rio Grande do Norte that had as protagonists the candidates at that moment Dilma Rousseff (PT) for president and Rosalba Ciarline (DEM) for governor. To do so, we based ourselves on the theory of Bakhtin Circle, which considers the statement as a unit of verbal communication and conceives language as a dialogical phenomena and a discursive practice and also in the conceptions of dialogical relationships, social voices and chronotope formulated by the previous mentioned theory. Still in the theoretical field, we have established an interconnection with the theories coming from the Cultural Studies (Hall, Woodward) about the identity, which conceives it as multiple, fragmented, non-fixed, so that, the subject assumes different identities, not always coherent, at different times, depending on the context in which they are approached. The research is situated in the frames of Applied Linguistics, which considers language as the center of its studies and settles on the border of an open number of areas of knowledge expanding its possibilities of investigation by means of the interdisciplinary. Our corpus consists in 20 electoral propaganda videos aired on TV during the Free Election Time in 2010 campaign; among these, 14 videos are Dilma Rousseff s propaganda and 06 videos are Rosalba Ciarline s propaganda. We seek for the purpose of the analysis to identify the identities which emerge from the discourses about the candidates in propaganda videos broadcasted in the referred campaign, as well as realize the dialogical relations established in these discourses and even if the identity construction of these subjects is located in the same axiological axis. The corpus analysis revealed that the multiple cultural identities of the candidates campaigning emerge in the discourses circulating in the electoral propaganda aired on TV such as: the identities of pioneer woman, competent, sensitive, mother, grandmother, religious. And, yet, those are changeable as the electoral demands, in other words, the need to obtain support and votes, outline a fluid identity construction about the candidate to the position in question

Tradução, adaptação cultural e avaliação psicométrica da prova cognitiva de leganés em uma população idosa brasileira com baixo nível de escolaridade

Introdução: The scales of cognitive screening are important tools for early detection of dementia, creating the possibility of developing measures to slow this process and assist in the management of the disease. Objective: To validate the Leganés Cognitive Test (Prueba Cognitive de Leganés) (PCL) for cognitive screening in low educated elderly Brazilians. Methods: The study sample was composed of 59 elderly residents from the city of Santa Cruz, Brazil with low schooling levels. Reliability was analyzed with a 2-day interval between assessments, and concurrent validity was assessed using the Mini Mental State Examination (MMSE). Results: According to the PCL, the prevalence of dementia was 11.8%. The scale items showed a moderate to strong correlation between domains (p <0.01), and inter-rater reliability exhibited ICC = 0.81, 95% CI (0.72-0.88). Factor analysis resulted in two factors: memory and orientation. Interscale agreement was considered poor (k = - 0.02), supporting the hypothesis of an educational impact on final MMSE scores. Conclusion: The results suggest that PCL has acceptable levels of reliability for use in low educated elderly Brazilians

Modelos de sobrevivência com fração de cura e erro de medida nas covariáveis

In this work, we study the survival cure rate model proposed by Yakovlev et al. (1993), based on a competing risks structure concurring to cause the event of interest, and the approach proposed by Chen et al. (1999), where covariates are introduced to model the risk amount. We focus the measurement error covariates topics, considering the use of corrected score method in order to obtain consistent estimators. A simulation study is done to evaluate the behavior of the estimators obtained by this method for finite samples. The simulation aims to identify not only the impact on the regression coefficients of the covariates measured with error (Mizoi et al. 2007) but also on the coefficients of covariates measured without error. We also verify the adequacy of the piecewise exponential distribution to the cure rate model with measurement error. At the end, model applications involving real data are made