Axisymmetric
Mostrando 25-36 de 75 artigos, teses e dissertações.
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25. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems
Abstract: Preliminary studies on field emission (FE) arrays comprised of carbon nanotubes (CNT) as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT) field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam fo
J. Aerosp. Technol. Manag.. Publicado em: 2010-04
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26. Evaluation axisymmetric analysis of thermal stress residual near fiber/epoxy interface
The finite element method is used to compute and analyze the residual stresses particularly near the fiber/epoxy interface, and these stresses need to be taken into account. An axisymmetric model has been used for stress computation and analysis, in this work two cases are considered by using an epoxy matrix with respectively glass and carbon fibers with a d
Materials Research. Publicado em: 2009-06
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27. CONVENTIONAL AND SIMPLIFIED-HYBRID BOUNDARY ELEMENT METHODS APLLIED TO AXISYMMETRIC ELASTICITY PROBLEMS IN FULLSPACE AND HALFSPACE / MÉTODOS DE ELEMENTOS DE CONTORNO CONVENCIONAL E HÍBRIDO SIMPLIFICADO APLICADOS A PROBLEMAS AXISSIMÉTRICOS DE ELASTICIDADE NO ESPAÇO COMPLETO E NO SEMI-COMPLETO
This thesis presents the formulation of the conventional and simplified-hybrid boundary element methods for axisymmetric problems, employng fullspace as well as halfspace fundamental solutions. As it is mostly found in the literature on axisymmetric problems in the elastic halfspace, the boundary element formulations make use of fullspace fundamental solutio
Publicado em: 2009
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28. Theoretical-experimental study on two-dimentional confined jets. / Estudo teórico-experimental de jatos bi-dimensionais confinados.
The main objective of this thesis is to study the mean flow inertial and pressure effects on the mean flow itself in two-dimensional confined jets. The flows considered in the present work are turbulent, isothermal, incompressible and single-fluid. The introduction and the bibliographical review are done by the following presentations: technological and fund
Publicado em: 2009
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29. Caracterização de junta soldada por atrito linear com mistura (FSW) da liga Al-Mg-Si AA 6063. / Friction stir welded joint characterization of 6063 aluminum alloy.
Friction Stir Welding process arose from a desire to apply the principles and benefits of traditional solid state friction welding friction in non axi-symmetric geometries. Thus, it was added a traveling speed and a special rotating tool that allows welding aluminum alloys with bad weldability. The key factor to have a linear friction welding with sound bead
Publicado em: 2009
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30. CFD analysis of laminar axisymmetric diffuser flow.
In this current work it is presented the two-dimensional axisymmetrical air flow simulations under laminar regime in a conical diffuser using Computer Fluid Dynamics (CFD). The use of diffusers in laminar flow can be seen in micro-pumps applications, especially for micro-electronics cooling. The objective is to analyze the static pressure recovery coefficien
Publicado em: 2009
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31. Experimental and numerical study of spouted bed fluif dynamics
Spouted beds, originally invented in Canada by Mathur and Gishler (1955) as an alternative to fluidized beds for handling coarse particles, are now widely studied in a variety of physical operations, such as drying, coating and granulation. In this work the particle velocity, minimum spouting flow rate and characteristic fluid-dynamic curves of the spouted b
Brazilian Journal of Chemical Engineering. Publicado em: 2008-03
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32. FLOW OF ELASTO-VISCOPLASTIC LIQUIDS THROUGH AN ABRUPT AXISYMMETRIC EXPANSION-CONTRACTION / ESCOAMENTOS DE LÍQUIDOS ELASTO-VISCOPLÁSTICOS ATRAVÉS DE UMA EXPANSÃO-CONTRAÇÃO ABRUPTA AXISSIMÉTRICA
Atualmente, o escoamento de fluidos não Newtonianos está presente em diversos processos industriais e também no dia- a-dia de todos. Na presente dissertação, inicialmente, é apresentada uma nova equação constitutiva capaz de modelar fluidos que possuam tanto elasticidade como viscoplasticidade, sendo este novo modelo definido como elasto-viscoplásti
Publicado em: 2008
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33. NUMERICAL ANALYSIS OF MECHANICAL BEHAVIOR OF THE SALT IN OIL WELLS / ANÁLISE NUMÉRICA DO COMPORTAMENTO MECÂNICO DO SAL EM POÇOS DE PETRÓLEO
The presence of saline structures around the world, in deepwater like the ones of the Mexican Gulf, Brazil, Angola, North and West Africa, provides favorable conditions for hydrocarbons imprisonment. It increases the probability of success in oil and gas exploration. In the Santos Basin, for example, it was recently noticed that a light crude oil located bel
Publicado em: 2008
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34. Aproximação de Galerkin mínimos-quadrados de escoamentos axissimétricos de fluido Herschel-Bulkley através de expansões abruptas / Galerkin least-squares approximations for herschel bulkley fluid flows through an axisymmetric abrupts expansions
O estudo de escoamentos de fluidos não-Newtonianos através de expansões desperta um grande interesse em pesquisadores nas diversas áreas da engenharia, devido a sua ampla aplicação em indústrias e no meio acadêmico. O objetivo principal desta Dissertação é simular problemas de escoamentos envolvendo fluidos viscoplásticos através de expansões a
Publicado em: 2008
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35. Método de otimização topológica aplicado ao projeto de sonotrodos para transdutores piezelétricos. / Topology optimization method applied to the design of transducers sonotrodos piezoelectric.
This work aims at the development of a method based on Topology Optimization to design a mechanical structure, called sonotrode, which is a device usually connected to a high power piezoelectric transducer (mechanical device capable of converting electric energy into mechanical displacement or vice-versa). A sonotrode transmits mechanical vibrations of a pie
Publicado em: 2008
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36. Galerkin least-squares solutions for purely viscous flows of shear-thinning fluids and regularized yield stress fluids
This paper aims to present Galerkin Least-Squares approximations for flows of Bingham plastic fluids. These fluids are modeled using the Generalized Newtonian Liquid (GNL) constitutive equation. Their viscoplastic behavior is predicted by the viscosity function, which employs the Papanastasiou's regularization in order to predict a highly viscous behavior wh
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2007-12