Internal Convection
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Numerical study of the influence of internal heat source in naturally ventilated offices
Abstract The natural ventilation in a building performs a fundamental role in users' welfare and health, when used as a bioclimatic and architectural strategy, it can provide brighter projects. Increasing the indoor air speed ventilation has an important performance maintaining indoor air quality, contributing to thermal interactions between human body and e
Rem: Rev. Esc. Minas. Publicado em: 2016-03
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2. DEVELOPMENT OF INSULATING MAGNETIC OIL FOR TRANSFORMERS
The Centrais Elétricas do Norte do Brasil AS – Eletronorte, as well as other companies in the world energy sector, have problems of loss of the performance by excessive heat and even accidents with their transformers. The maintenance and accidents impact of energy supply, generating profit and more expensive insurance premiums. The transformers are essent
Publicado em: 20/07/2014
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3. Estudo de desempenho de esguichos para túneis de pasteurização / Study on sprays performance for pasteurization tunnels
Atualmente na indústria alimentícia é comum a efetivação do processo de pasteurização em túneis, onde um fluido, geralmente água, é utilizado para transferir para o produto a energia térmica necessária. Por causa disso, um dos fatores importantes deste procedimento é a maneira como este fluido é aspergido por sobre o produto a ser pasteurizado.
Publicado em: 2010
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4. Experimental study of the heat transfer in the intermittent horizontal two-phase flow pattern / Estudo experimental da transferencia de calor no escoamento bifasico intermitente horizontal
The main objective of the present work is the experimental measurement of the two-phase heat transfer coefficient in the intermittent horizontal gas-liquid flow pattern. This flow pattern is very common in oil production pipelines. In order to reach this objective, an experimental apparatus was built, consisting of a test section fed with an air-water mixtur
Publicado em: 2009
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5. Natural convection heat transfer in partially open enclosures containing an internal local heat source
A numerical study was conducted to investigate steady heat transfer and flow phenomena of natural convection of air in enclosures, with three aspect ratios (H/W = 1, 2, and 4), within which there is a local heat source on the bottom wall at three different positions, Wh. This heat source occupies 1% of the total volume of the enclosure. The vertical walls in
Brazilian Journal of Chemical Engineering. Publicado em: 2007-09
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6. Transient convective heat transfer
In nature, as well as within the human-made thermal systems, the time-variable regimes are more commonly encountered, if not always, than the permanent regimes. Nevertheless, studies in convection are still more frequent in the permanent regimes, undoubtedly due to the related difficulties in calculation in terms of time and cost of computation. One may dist
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-03
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7. Modelagem do balanço de energia do dossel da cultura do pimentão em casa de vegetação. / Canopy energy balance modeling of sweet pepper cultivated in greenhouse.
In a greenhouse production system, the canopy of culture is the main element that modifies the internal microclimate. Its comprehension is very important to understand the energy exchange process. Due to the complexity interaction among several elements, the modeling represents an important tool for research in protected environments, but little used in Braz
Publicado em: 2005
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8. Caracterização da microestrutura dendritica na solidificação vertical descendente de ligas AL-CU / Characterization of dendritic array during downward transient directionally solidified AL-CU alloys
The dendritic spacings are important microstructural parameters, involved in solidification processes. They can affect not only microsegregation profiles but also the formation of secondary phases within interdendritic regions, which influences mechanical properties of cast structures. A small number of studies have been carried out in order to analyze the e
Publicado em: 2004
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9. Comparison between one-dimensional uncoupled and convection-conduction conjugated approaches in finned surface heat transfer
This work studies the forced convection problem in internal flow between concentric annular ducts, with radial fins at the internal tube surface. The finned surface heat transfer is analyzed by two different approaches. In the first one, it is assumed one-dimensional heat conduction along the internal tube wall and fins, with the convection heat transfer coe
Journal of the Brazilian Society of Mechanical Sciences. Publicado em: 2000
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10. Thermal Energy Exchange Model and Water Loss of a Barrel Cactus, Ferocactus acanthodes1
The influences of various diurnal stomatal opening patterns, spines, and ribs on the stem surface temperature and water economy of a CAM succulent, the barrel cactus Ferocactus acanthodes, were examined using an energy budget model. To incorporate energy exchanges by shortwave and longwave irradiation, latent heat, conduction, and convection as well as the h
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11. Gross Thermodynamics of Heat Engines in Deep Interior of Earth
From the gross conservation laws of thermodynamics in a convecting material we derive a bound on the ratio of the rate of production of mechanical or magnetic energy to the rate of internal radioactive heating which drives the convection. Our bound for this “efficiency” depends on the temperatures in the material, and can exceed unity. Whether the bound
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12. Equilibrium temperature in a clump of bacteria heated in fluid.
A theoretical model was developed and used to estimate quantitatively the "worst case", i.e., the longest, time to reach equilibrium temperature in the center of a clump of bacteria heated in fluid. For clumps with 10 to 10(6) cells heated in vapor, such as dry and moist air, and liquid fluids such as purees and juices, predictions show that temperature equi