Simulação numérica da combustão turbulenta de gás natural em câmara cilíndrica

O presente trabalho apresenta uma modelagem detalhada de processos de combustao turbulentos para um jato concentrico de combustıvel e ar. A modelagem é fundamentada nas equacões de conservacão de massa, de quantidade de movimento, de energia e de espécies quımicas. A turbulencia é resolvida pela utilizacão do modelo k- padrão. Dois modelos de reacões quımicas são apresentados. O modelo SCRS – Simple Chemically-Reacting Systems, que assume taxas instantâneas de reacões quımicas. Também é abordado o modelo E-A – Eddy Breakup - Arrhenius, que assume taxas finitas de reacões quımicas. A radiacão térmica, fenômeno de grande importância devido as altas temperaturas alcancadas em processos de combustão,é modelada através do Método das Zonas. O modelo da soma ponderada de gases cinzas – WSGGM,é usado para determinar o espectro de emissão e absorcão dos gases no processo. Para a solucão destas equacões diferenciais, juntamente com os modelos de turbulência, de reaçõoes químicas e radiação térmica, faz-se o uso do Método dos Volumes Finitos. Para validar a modelagem apresentada resolve-se o processo de combustão em uma câmara cilíndrica. A câmara de combustão usada áa mesma abordada no First Workshop on Aerodynamics of Steady State Combustion Chambers and Furnaces, organizado pela ERCORTAC - European Research Community On Flow Turbulence And Combustion, em outubro de 1994, que apresenta dados experimentais de temperatura e concentração das espécies químicas para várias posições de interesse no interior da câmara. Utiliza-se o gás natural como combustível e o ar atmosférico como oxidante. O processo de combustão sem pré-mistura é resolvido para a condição de excesso de combustível de 5 % para ambos os modelos, onde o gás natural é injetado por um duto circular central, e o ar atmosférico por um orifício anular externo a esse duto, no mesmo plano Uma reação química não estagiada é assumida para o modelo SCRS. Para o modelo E-A duas situações são resolvidas: combustão não estagiada, com uma etapa global de reação química; e reação quımica estagiada, com duas etapas globais. Os resultados obtidos com o modelo SCRS para a distribuição de temperaturas, em termos de tendências gerais, são razoáveis. Já as concentrações de espécies químicas não apresentam dados satisfatórios para este modelo. Para o modelo E-A os resultados apresentam boa concordância com os dados experimentais, principalmente para a situação em que o processo de combustão é assumido em duas etapas globais. ´E analisado em detalhe o papel desempenhado pela transferencia de calor por radiacao, com meio participante. Para melhor verificar as trocas de calor, assume-se uma camara de combustao cilındrica com paredes d’agua. A injecao do combustıvel e do oxidante e feita atraves de um queimador central, semelhante ao usado para validar a modelagem, porem com dois orifıcios concentricos para injecao de combustıvel. Nesta situação o efeito do turbilhonamento (swril), assumido como 20 % da velocidade axial de entrada, sobre a injecao de ar e computado atraves da condicao contorno da equacao de conservacao da quantidade de movimento angular. Nesta fase apenas o modelo E-A, com duas etapas globais de reacoes quımicas, e considerado, ja que o mesmo apresenta os melhores resultados. O processo de combustao e simulado com e sem a presenca da radiacao termica. Verifica-se que a presenca da radiacao termica homogeneiza a temperatura dos gases no interior da camara. Com isso verifica-se tambem alterações nas taxas de reacoes quımicas, modificando a magnitude das fracoes das especies quımicas Quando a radiacao termica e considerada efeitos de extinção local da chama sao verificados nas regioes de temperaturas mais altas, diminuindo o consumo de oxigenio e aumentando a producao de monoxido de carbono, caracterizando assim uma combustao incompleta. Em algumas situacoes tem-se uma variacao de temperatura de ate 500 K, a montante da chama. A radiacao termica tambem aumenta a taxa de transferencia de calor dos gases quentes para as paredes da camara, e desta para o seu exterior. Com os resultados obtidos a partir desta modelagem e possıvel determinar o perfil da zona de combustao, a distribuicao de concentracoes de especies quımicas, o campo de velocidades e as taxas de transferencia de calor para as paredes da camara de combustao, total, por conveccao superficial e por radiacao. Estes resultados sao de extrema importancia para prever a performance de camaras de combustao, assim como auxiliar na sua otimizacao.

Ensaio sobre o agente racional: esparadrapos para um paciente terminal?

The Rational Agent model have been a foundational basis for theoretical models such as Economics, Management Science, Artificial Intelligence and Game Theory, mainly by the ¿maximization under constraints¿ principle, e.g. the ¿Expected Utility Models¿, among them, the Subjective Expected Utility (SEU) Theory, from Savage, placed as most influence player over theoretical models we¿ve seen nowadays, even though many other developments have been done, indeed also in non-expected utility theories field. Having the ¿full rationality¿ assumption, going for a less idealistic sight ¿bounded rationality¿ of Simon, or for classical anomalies studies, such as the ¿heuristics and bias¿ analysis by Kahneman e Tversky, ¿Prospect Theory¿ also by Kahneman & Tversky, or Thaler¿s Anomalies, and many others, what we can see now is that Rational Agent Model is a ¿Management by Exceptions¿ example, as for each new anomalies¿s presentation, in sequence, a ¿problem solving¿ development is needed. This work is a theoretical essay, which tries to understand: 1) The rational model as a ¿set of exceptions¿; 2) The actual situation unfeasibility, since once an anomalie is identified, we need it¿s specific solution developed, and since the number of anomalies increases every year, making strongly difficult to manage rational model; 3) That behaviors judged as ¿irrationals¿ or deviated, by the Rational Model, are truly not; 4) That¿s the right moment to emerge a Theory including mental processes used in decision making; and 5) The presentation of an alternative model, based on some cognitive and experimental psychology analysis, such as conscious and uncounscious processes, cognition, intuition, analogy-making, abstract roles, and others. Finally, we present conclusions and future research, that claims for deeper studies in this work¿s themes, for mathematical modelling, and studies about a rational analysis and cognitive models possible integration. .

As mudanças nos processos de gestão do conhecimento: o caso Embratel

o aumento da competição despertou nas organizações a necessidade de reverem seus processos. Com o advento do fenômeno da globalização, associado ao desenvolvimento das telecomunicações, da tecnologia da informação e dos processos de logística, os mercados ficaram cada vez mais restritos, fazendo com que a inovação no desenvolvimento de produtos e o correto entendimento das necessidades dos clientes passassem a representar um diferencial de mercado. Para os profissionais, estas mudanças representaram novos desafios no tocante à cobrança por resultados e à manutenção da empregabilidade. No meio de todas estas mudanças, surge no cenário empresarial e acadêmico um novo processo de gestão, conhecido por gestão do conhecimento. Além disso, os efeitos deste novo cenário levou à abertura de mercados até então restritos, dentre eles o de telecomunicações, cujas empresas operadoras brasileiras foram privatizadas em 1998. Entre ela, insere-se a Empresa Brasileira de Telecomunicações (Embratel), criada em 1965 com a função de integrar o país por meio das telecomunicações. Atuando com um perfil de engenharia por 30 anos, a Embratel se viu obrigada a promover profundas mudanças em seus processos internos e no perfil de seus profissionais para se transformar em uma empresa prestadora de serviços, implantando e reformulando sistemáticas voltadas à aquisição e desenvolvimento de novas competências. Este estudo apresenta uma análise das mudanças do processo da gestão do conhecimento na EmbrateL a partir da privatização do setor de telecomunicações no Brasil. O método utilizado foi a análise de conteúdo, feita com base em dados coletados no campo, em documentos e na bibliografia existente. F oram analisados os principais processos da gestão do conhecimento ao longo da vida da EmbrateL dividindo-a em três períodos: de 1965 a 1994, período essencialmente estatal; de 1995 a 1997, período em que a empresa viveu sua transição para a privatização, e a partir de 1998, período de ambiente privado. O estudo permitiu concluir que, apesar de terem sido observadas mudanças nos indicadores de aquisição e desenvolvimento de conhecimento, a Embratel demonstra ser uma empresa na qual sempre existiu o processo de gestão do conhecimento, o que certamente contribuiu para sua história de sucesso.

Estudo da influência das competências dos níveis operacionais sobre os processos de estratégia: o caso da empresa farmacêutica MERCK S.A

Based on the approaches and studies on the subject of organizational strategies aimed at intra-firm aspects, resources and competencies developed by organizations have been identified as the key elements toward assessing and explaining a company¿s performance. Considering such perspective, it has been observed that the development and effective implementation of organizational strategies depend on the skills and knowledge supplied by workers who are motivated or led to contribute with their effort so as to meet the organization¿s goals. Considering this, the purpose of this dissertation is to identify how the competencies of the operational levels of an organization are mobilized to contribute to the shaping and implementation of organizational strategies. This assessment was accomplished by observing the existing relationships between organizational and human resources management processes and processes of short term and long term strategies in a company of the pharmaceutical industry. The analysis of the evidence collected during the observation of this company has shown a strong link between personnel processes and the accomplishment of short term strategic goals, and a weaker link with the establishment of long term strategies. As a rule, the corporation¿s operational levels have little influence on the strategic planning and its implementation, even though the company uses a model of competencies designed to create more effective and measurable relationships between individual competencies and the company¿s performance.

Estruturação e processos isomórficos do campo organizacional de alambiques de cachaça artesanal em Bananal - SP

This work tries to comprehend, throw the prism of the Institutional Theory, the structural process of organizational field of cachaça¿s handicraft producers¿ from a Brazilian countryside region. The role of values and traditions on the determination of the structure and decision making on this industry are analyzed. It is necessary to research historic, economic and social facts, and confront them to the formation of Brazilian society to understand the field¿s formulation. An important aspect of this research is the mapping of isomorphic process and the comparison of the field¿s institutional degree, before and after the changes. It was noticed that the alteration on perception of Cachaça in the national market and the entrance of a new actor oriented by functional rationality are the major reasons for the mimetic changes on this field. As a contribution, this study confirms the applicability of Institutional Theory on analysis of specific fields and shows how this field has structured itself.

Fatores que impactam a implantação de tecnologias de gestão baseadas em processos em uma empresa pública

O mundo está passando por grandes mudanças que vêm afetando as esferas sociais, tecnológicas, empresariais e mentais. As empresas têm sido ameaçadas por diversos fatores como rapidez no lançamento de novos produtos, interferência dos governos, clientes cada vez mais conscientes e exigentes, aumento da concorrência, globalização e o surgimento constante de novas tecnologias. Essas mudanças exigem das empresas uma estrutura mais flexível capaz de absorver as rápidas necessidades do ambiente, e o formato atual não tem se mostrado adequado para vencer estes desafios. Nesse contexto, a gestão baseada em processos tem se mostrado promissora ao ser incorporada nas principais tecnologias de gestão como BSC, NBR ISO 9000, gestão de custos com ABC, entre outras. Como toda nova abordagem, as tecnologias (ou modelos) baseadas em processos sofrem de vários problemas, sendo alguns já conhecidos, como resistência às mudanças, falta de preparo e apoio insuficiente da alta direção. Os estudos desses fatores são incipientes e em sua maioria não tratam de seus impactos em empresas públicas. Esse trabalho tem como objetivo justamente identificar esses fatores na literatura (teoria e casos de estudo) e confrontá-los com aqueles encontrados em uma empresa pública (estudo de caso), analisando sua pertinência. Os resultados encontrados, além de confirmarem os fatores, sugerem que a sua utilização, na forma de um checklist, podem beneficiar as empresas na prevenção, redução ou eliminação de problemas que impactam ou inviabilizam um projeto.

A percepção dos indivíduos sobre a inserção de tecnologias de informática nos processos de mudança organizacional: um estudo de caso

This dissertation presents a research aimed at identifying and explaining the individual perceptions as far as the introduction of computer technology concerning the organization change process and the reason underlying those changes, utilizing for study purposes, a customer attendance agency of INSS , located in São Luís-MA, which data collection was carried out by interviews with three managers and application of to thirty employees, all of them working at the unit researched. The core point was to identify feelings and perceptions of individuals, and the reason steering the change actions deployed in this office. Based on this perception, it is presented a literature review on the main thinkers who discussed the role, and the relevance of reasoning in the development of human relations, both in the organizations and in society. To start with, Max Weber thinking on rationality was introduced, on the sequence, the discussion raised by the Frankfurt School in its first phase, mainly on the Max Horkheimer thinking and finally it is shown a summary of Jurgen Habermas thinking, mainly concerning its communicative action theory proposed as a path to emancipation of individual of current instrumental reasoning. Summing up, we can conclude from this research that perceptions, feelings and opinions indicate that the institution uses to discuss with the civil servants the implementation of change process. For those servants the excessive functional control, the limitation of knowledge production and an artificial functional integration are consequences of the shape and intensity, as well as of computer technologies deployed in the institution. It is also shared by most of civil servants, including managers, that the overall participation would have more validity and would decrease the resistance to those changes. And it is also worth registering that despite of the servants having job stability, only 50% have positive expectations as far as its future in the institution.

A complexidade da gestão em processos de internacionalização: como a cultura Nacional impacta o processo decisório de gestores brasileiros expatriados - o caso de uma empresa estatal do setor de energia

In a world where the companies are trying to compete on a global scale, the positioning strategies direct them to go beyond the geographical boundaries of their base countries, seeking for other markets, as a way to keep globally competitive. These conditions make crucial the roles performed by their managers, exposed to different contexts, mainly economical, political, social and cultural and to face the task to manage enterprises like a challenge, probably bigger than the one found on their base countries. This speech tries to examine how much expatriated Brazilian managers feel the influence of local cultural factors in their decisional processes, taking into consideration that they are embedded in their cultural home countries, and they can suffer an impact by the culture of other countries. With this research it is intended to gather empirical material that will supply clues and allow to advance on studies that will make a relationship between decisional process and local culture, through a case study in a Brazilian state-owned energy company and its subsidiaries in South American countries, hoping that the mentioned studies will somehow contribute to a better understanding of the problems that have been stressed in the last decades. Also considering that the vast majority of the theoretical and empirical material about this matter has its own source on the western developed countries and are, in this way, culture-bounded, we hope to increase the production of studies and researches applied to the Latin American reality, mainly the Brazilian one.

Processos de aprendizagem e acumulação de competências tecnológicas na indústria de injeção plástica: o caso da Multibrás da Amazônia S.A.

This resume focus the connection between the learning process and the technological competences evolution. It is based on business case of a plastic injection company named Multibras da Amazonia S/A, that manufacture plastic parts to electro- electronic industry assemblers, the study used the company evolution from 1983 to 2000. Its conclusion allowed to demonstrate, how the theories developed by Figueiredo (2001) can be used to describe the technological competences and the learning process, and on it's scale from 1 to 6 the Multibras case has reached the level 5. Based on the business case, the study confirmed how the technological competences learning process and accumulation is linked to an organizational knowledge. Using the theory basis, but applied to an industry case, different from all the previous studies, this resume shows that it's necessary to have a continuous, organized and integrated effort to generate and develop the knowledge evolution inside the company to make possible the technological competences accumulation on a fast and effective track.

A utilização da grafologia nos processos de seleção de pessoal

This research has the objective of analyze the possibilities offered by the use of the graphology in the process of personnel's selection that aim at the completion of current vacancies of job offers. The study is based in the verification of the applicability and forms of use of selection instruments of personal, mainly of those developed with objective of identifying the aptitudes and the characteristics of the individual's personality. Analyzing its applicability, as form of adapting to the reality today, the graphology, besides assisting to the new variables that the global changes impose to the individuals' behavior and his relationship with the companies, appears as alternative and it is occupying, every day, more space in the professional evaluation area. This study offers reasons so that one can consider the graphology analysis as one more instrument to be used in personnel's selection, in agreement with the possibilities and identified limitations, when used for that end. Tends as objective to explain the reasons of the use of the graphology analysis as evaluation tool, the exploratory and explanatory researches were adopted. This explanation will appear, then, of the verification and analysis of the data obtained in the bibliographical and of field researches, which allows like this to base its report, development and applicability.

Acumulação de competências tecnológicas e os processos subjacentes de aprendizagem na indústria Mmtal - mecânica : o caso da empresa AGCO comércio e indústria LTDA em Santa Rosa - RS

This dissertation enfoca the relationship between technological competences accumulation and the learning underlying processes. This relationship is examined in the company AGCO Comércio and Indústria Ltda, during the period of 1970 to 2000. It is of a company metal-mechanics, agricultural machines manufacturer. In other words, the dissertation examines the processes technological learning implications for aA technological competences accumulation in the company in study. The dissertation enfoca the competences accumulation for three technological functions: processes and organization, products and equipments. The learning processes are examined to the light of four characteristic: variety, intensity, operation and interaction, from the structure existing analysis use in the literature. Based on study of individual case, this study found that the technological competences ways to accumulation in the studied company are associates to the several processes used to acquire technological knowledge and converts him in organizacional. Ademais, the simple incidence of these processes in the company didn't guarantee in the company a positive implication for the technological competences accumulation. The company accumulated level middleman-superior technological competence (level 6) to accomplish production and function products function processes and organization activities, and intermediary level (level 5) to accomplish function equipments activities. In haves to characteristic key, the learning processes introduce an oscillation differentiated along time: the variety oscillated of moderated the several; the intensity of intermittent the continuous; the operation of bad the good; and the interaction of weak the strong. Through the existing structure use in the literature, however applied to a previous studies different industry, this dissertation suggests that must there be an organized , continuous effort and integrated for the knowledge generation and sowing in every company in order to the technological training accumulation be accelerated in the company.

Acumulação de competências tecnológicas e os processos subjacentes de aprendizagem na indústria de bens de capital: O caso KVAERNER PULPING no Brasil

This dissertation is concerned with the implications of the learning processes for the technological capability accumulation at the firm level. This relationship was examined in Kvaerner Pulping over the period from 1980 to 2000. The firm is located in Curitiba/PR and supplies equipment and complete plants (capital goods) for pulp mills. In other words, based on an individual case study, this dissertation examines how the learning processes influence the building and accumulation of technological capability. The accumulation of technological capabilities is crucial for the survival and the competitive performance of the firms. An analytical framework already available in the literature was used to describe the paths (way and speed) of technological capability accumulation in the firm studied. However, the framework was adapted specifically for the capital goods industry for the pulp & paper sector. The paths of technological capability accumulation are analysed for three different technological functions: ¿engineering activities and project management¿, ¿operational processes and practices¿ and ¿process equipment¿. The learning mechanisms were examined in the light of four key features: variety, intensity, functioning and interaction. During the 1980s and 1990s the firm accumulated different levels of technological capability in the technological functions studied. It was only when the firm started to coordinate systematically the efforts to acquire and convert the knowledge from the individual to the organizational level, at the mid 1990s, that the accumulation of technological capability was accelerated. By the end of this decade the firm was able to accumulate innovative capabilities in all the functions analysed. Similarly to previous studies that investigated other types of firms, the conclusion of this dissertation suggests that the way and rate by which the firm accumulates technological capability can be explained by the learning process and its key features over time.

Acumulação de competências tecnológicas e os processos subjacentes de aprendizagem na indústria eletrônica de consumo : o caso da SHARP do Brasil S/A

Esta dissertação estuda o relacionamento entre a acumulação de competências tecnológicas e os processos subjacentes de aprendizagem. O estudo desse relacionamento foi examinado na fábrica de eletrônica de consumo Sharp do Brasil S/A, situada na cidade de Manaus, durante o período de 1972 a 2000. A acumulação e sustentação de competências tecnológicas são desenvolvidas através de processos de aprendizagem nas organizações. Os processos de aprendizagem estão relacionados diretamente à taxa de acumulação de competências tecnológicas das organizações. A dissertação, utilizando a estrutura de análise existente na literatura, examina os processos de aprendizagem à luz de quatro características: variedade, intensidade, funcionamento e interação. A acumulação de competências é analisada a partir de duas funções tecnológicas: processo/organização e produtos. Ao longo do periodo analisado, a empresa acumulou diferentes níveis de competências tecnológicas e com velocidades variadas nas funções estudadas. Na década de 80, a empresa através de uma melhor coordenação de esforços, passou a adquirir e converter conhecimentos individuais em conhecimentos organizacionais, acelerando o crescimento da taxa de competências tecnológicas acumuladas. Ainda no final da década 80, a empresa foi capaz de acumular competências inovadoras nas duas funções estudadas. A acumulação de competências tecnológicas é um aspecto importante a competitividades e sobrevivência das organizações. No entanto, somente a acumulação de competências tecnológicas não garante o bom desempenho e a sobrevivência da organização. A empresa estudada, apesar da acumulação de elevados níveis de competências tecnológicas ao longo do periodo, enfrenta uma grande crise financeira. A conclusão desta dissertação sugere que a taxa de acumulação de competências tecnológicas pode ser explicada pela capacidade da empresa em socializar e codificar a aprendizagem individual, adquiridas por processos externos e internos de aprendizagem aplicados de forma contínua e organizada, convertendo em aprendizagem organizacional.

Comportamento dos processos intra-organizacionais de aprendizagem tecnológica frente a uma mudança de estrutura de propriedade: o caso da TermoMacaé - PETROBRÁS

This academic work describes the interfirm technological learning processes behavior at a thermo plant throughout the years 2001 till 2007. Its former ownership structure was composed by two foreigners companies. This structure was changed by the acquisition of the company control by a Brazilian state owned company on April 2006. The company is a Natural Gas Fired Power Plant placed at Macaé City, at Rio de Janeiro State, Brazil generating electric power right to National Integrated System (SIN). The goal of this research is verify how the technological knowledge had been acquired by the firm and how it had been spread out throughout the organization before and after the change of the ownership structure. The taxonomy applied to determining of ownership structure take in account three parameters: type, specific characteristic and the ownership structure itself. Technological Learning Interfirm Processes have been examined from a model of systemic approach that establishes four key characteristics: ¿variety, intensity, functioning and interaction¿. During 2001 until 2006, till the change of owner structure, the firm developed its own learning processes in its own operational routines. The main learning processes have been identified from empirical evidences. It has been adopted the cut line at year of 2006 for the comparison among the technological learning processes behavior, when the change of ownership structure took place. The data capture occurred within April and August 2007 covering since 2001. Verified the behavior of these learning processes before and after the ownership structure changed from private property to state owned property. The conclusion of this case study suggests that interfirm processes of technological learning identified by the research had their dynamical behavior promptly affected by a change from private to ownerstate ownership structure, exposing the company to a poor performance in its industry, due to the lack of 51% of the technological intrafirm learning processes and reduction of the acquisition of new technical knowledge and its conversion throughout the organization.

Acumulação de competências tecnológicas em processos e produtos e aprendizagem tenológica: o caso da ELETROLUX do Brasil S/A - Unidade de Guabirotuba - Curitiba/PR

This dissertation is concerned with the implications of the learning process on the technological capabilities accumulation. This relationship was examined at the Electrolux do Brasil S/A ¿ Guabirotuba Unity ¿ in Curitiba/PR, over the period of 1980 to 2000. The Brazilian factory products White Goods destined to the Brazilian market as well as to exportation. The Swedish group Electrolux, to which the Brazilian factory belongs to, produces and sell goods to more then 150 countries. Regardless their importance, studies on the accumulation of technological capabilities and the underlying learning process are still scarce in Brazil, especially those focusing on the eletrodomestics products, and more specifically on the refrigerators and freezers industry. Based on a case study in the Electrolux do Brasil S/A, from 1980 to 2000, this investigation examined the influence of the learning process in the paths of the technological capabilities accumulation in the firm. The learning processes were analyzed in the light of the analytical framework proposed by Figueiredo (2001). This framework consists in four key features: variety, intensity, functioning and interaction. The technological capabilities accumulation were studied considering two technological functions: Process and Production Organization Activities and Products Activities. The evidences to classify and describe the paths of technological capabilities accumulation as well as to analyse the learning were mainly qualitative. This investigation joins other previous studies, in which there was noticed that the learning process have great involvement on technical changes, playing a relevant role on the technological capabilities of a company. Based on the investigation done and on the practical utilization of the analytical structure proposed by Figueiredo (2001), we infer that the way and the speed of technological capabilities accumulation are related to how the various learning processes were used by the company. One implied that, in levels from one to six, the studied company cumulated capabilities to level (5). Regarding technological competence, it approached industrialized countries firms, which present level (6), advanced.