Rotating Machines
Mostrando 1-12 de 20 artigos, teses e dissertações.
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1. A System Based on Artificial Neural Networks for Automatic Classification of Hydro-generator Stator Windings Partial Discharges
Abstract Partial discharge (PD) monitoring is widely used in rotating machines to evaluate the condition of stator winding insulation, but its practice on a large scale requires the development of intelligent systems that automatically process these measurement data. In this paper, it is proposed a methodology of automatic PD classification in hydro-generato
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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2. Avaliação de mancais hidrodinâmicos com descontinuidades geométricas / Evaluation of hydrodynamic bearings with geometric discontinuities
Hydrodynamic bearings are widely used in rotating machines, being the element responsible for the interaction between the rotor and the supporting structure. Therefore, in order to describe the dynamic behavior of the rotating shafts, it is necessary to know the journal bearings characteristics. For this reason, the purpose of this work is to analyze the dyn
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2011
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3. Detecting faults in rotating machines
Publicado em: 2011
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4. Integração de sistemas rotor-mancais hidrodinâmicos-estrutura de suporte para resolução numérica / Integration of rotor-hydrodynamic bearings-support structure systems for numerical resolution
The Rotordynamics occupies a prominent position in the design of machines and structures, due to the wide application of rotating machinery and the importance of the knowledgment of its operation for purposes of optimization and design for cost reduction, quality improvement and increased component life cycle. These machines and their components have peculia
Publicado em: 2010
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5. Análise de geometrias com curvas fechadas no tempo / Analysis of Geometries with Closed Timelike Curves.
This work deals with the analysis of cylindrically symmetric and stationary space-times Ct with closed timelike curves. The equation of motion describing the evolution of a massive scalar field in a Ct space-time is obtained. A class of space-times with closed timelike curves describing cosmic strings and cylinders is studied in detail. In such space-times,
Publicado em: 2010
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6. Contribuição ao Estudo de Máquinas Rotativas na presença de Não-Linearidades / Contribution to the Study of Rotating Machines containing nonlinearities
Esta tese procura enfocar problemas relacionados a rotores inteligentes, ou seja, aqueles que são capazes de monitorar seu comportamento dinâmico, analisálo, propor soluções com certa autonomia e garantir seu funcionamento mesmo quando do aparecimento de falhas que podem comprometer seu comportamento seguro ou sua eficiência. Este trabalho, de maneira
Publicado em: 2010
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7. Modeling of dynamic rotors with flexible bearings due to the use of viscoelastic materials
Nowadays rotating machines produce or absorb large amounts of power in relatively small physical packages. The fact that those machines work with large density of energy and flows is associated to the high speeds of rotation of the axis, implying high inertia loads, shaft deformations, vibrations and dynamic instabilities. Viscoelastic materials are broadly
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2008-03
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8. Detecção da condição de rubbing em maquinas rotativas atraves da transformada Wavelet / Detection of rubbing condition on rotating machinery by wavelet transform
This work presents a detection procedure of the rubbing phenomenon and its effects in rotating machinery, applicable on the stationary and non-stationary regimes, using the Wavelet Transform as analysis tool. Firstly, the Continuous Wavelet Transform (CWT) is applied for stationary signals using the Complex Morlet wavelet as mother wavelet, for extracting of
Publicado em: 2008
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9. Identificação de parametros de mancal através de analise de correlações / Bearing parameters identification through correlation analysis
This work presents an identification methodology of stiffness and damping parameters of rolling bearings in a rotor-bearing system. The proposed method is based on Ljapunov matrix equation and state space representation. Through the definition of correlations used in matrix equation, it is possible to generate an algorithm that relates system physical parame
Publicado em: 2008
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10. Modal parameter identification of structures and rotating machine by adaptative filter / Identificação de parametros modais de estruturas e maquinas rotativas atraves da filtragem adaptativa
This work investigates the use of adaptive filters for parameter identification. Although adaptive algorithms are still rarely utilized in the mechanical engineering field, the recursive least square and recursive least square with QR decomposition methods can be implemented based on the second ordinary differential equations in order to characterize the mod
Publicado em: 2007
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11. Atenuação de vibrações em máquinas rotativas flexíveis usando materiais viscoelásticos nos suportes / Vibration attenuation of flexible rotating machines by using viscoelastic absorbers in the supports
O objetivo deste trabalho é o estudo de uma metodologia para o controle passivo de vibração aplicada a rotores flexíveis, baseada no uso de absorvedores viscoelásticos. Desta forma é aproveitado o alto potencial que oferecem estes materiais para uso em aplicações industriais como absorvedores de ruído e vibrações. Para este fim foi projetado um si
Publicado em: 2007
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12. Optimization in design parameters of mechanical systems using multi-objective genetic algorithm / Otimização de parametros de projeto de sistemas mecanicos atraves de algoritmo genetico multi-objetivos
The mechanical systems are designed to be applied to any specific situations, and in this waytheir features should be measured to guarantee confidence to the systems. Their development and analysis expose the designer to a series of unknown parameters from several sources such as material properties, environmental and operational conditions. In terms of math
Publicado em: 2007