76 resultados para Coeficiente de transferência de calor médio


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Física - IGCE

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Mecânica - FEG

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Poultry facilities must provide an environment that ensures thermal comfort allowing the animal to express its genetic potential for production; and new tools are being applied to measure the thermal comfort, especially thermal cameras. The objective of this study was to evaluate the association of the surface temperature of the birds with those from the facilities, and estimate the sensible heat transfer. For this, the thermal conditions of rearing in two aviaries with different ventilation systems, during the period of March to April 2011 were recorded. The aviaries were divided into six quadrants for the registration of surface temperatures obtained using an infrared thermal camera. In each quadrant the ambient temperature, relative humidity and wind velocity during the obtention of images were also recorded. It was observed that the surface temperatures of birds are associated with the surface temperature of the rearing facilities (side curtains, roof and litter). In aviary with negative pressure higher wind speeds compared to the conventional one were recorded and; therefore, allowed a higher sensible heat transfer by birds, suggesting that this provided better conditions for thermal comfort.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Mecânica - FEG

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The present work intends to study some fluid dynamic and heat transfer aspects of a solar chimney, aiming at a preliminary design of a facility. Some definitions and concepts of this system are presented. The simulation was performed based on a theoretical model validated with measurements of a prototype in Manzanares, Spain. Using the same theoretical model and some considerations, dimensions on a small scale are applied, making the model more interesting from its constructive aspect. The results show the behavior of the air velocity inside the chimney and illustrate some values of two preselected turbines. This technology looks promising in Brazilian territory due to high levels of solar radiation

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper aims to study the thermal aspects involved in a liquid cooling system for processors, analyzing their competitiveness and efficiency across the fins and fan system usually used by personal computers, because electronic components become more potent and consequently current methods of cooling are becoming ineffective. The liquid cooling system and air cooling system have different heat transfer mechanisms that involve mainly convection and conduction heat transfer modes, and, furthermore, requires an analysis of fluid dynamics, which can evaluate the losses involved in the closed system, consisting in an exchanger heat pipe and water blocks in liquid cooling system or heat sink and turbo-axial fan in the air cooling system

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Induction heating is a process closely linked to the concepts of heat transfer. It also covers electromagnetic induction and effect of film. Many companies use this technology in their processes due to the high accuracy that can be obtained at temperatures induced. However the dominance of this technology is not common among Brazilian industries. This involves complex systems of equation and heat exchange in transient conduction, and convection and radiation losses. With this work we seek the ability to analyze which parameters influence over this process and the order of magnitude of time required for heating a cylindrical part

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The internal combustion engine is a heat engine widely used in the automotive industry. In order to better understand its behavior many models in the literature have been proposed in the last years. The 0-D thermodynamic model is a fairly simple tool but it is very useful to understand the phenomenon of combustion inside the chamber of internal combustion engines. In the first phase of this work, an extensive literature review was made in order to get information about this kind of analysis and, after this, apply them in a model able to calculate the instantaneous temperature and pressure in one zone of the combustion chamber of a diesel engine. Therefore some considerations were made with the aim of increasing the accuracy of the model in predicting the correct behavior of the engine, adding the combined effects of heat transfer, leakage and injection. In the second phase, the goal was to study the internal flow of a three-dimensional model of an internal combustion engine. In order to achieve this goal the software Solidworks was used to create the geometries of an engine and the suite of softwares Ansys was used to create the moving mesh (ICEM CFD and CFX-Pre) and to solve the CFD problem (Ansys CFX code). The model was able to perform the air flow simulation during the four-stroke cycle of an engine: admission, compression, expansion and exhaust. The results obtained from both models were suitable and they open a new range of possibilities for future researches on the field

Relevância:

100.00% 100.00%

Publicador:

Resumo:

O objetivo deste estudo é obter um modelo matemático logístico que representa a vaporização de toras de Eucalyptus grandis, em função do diâmetro e do tempo de permanência das toras no tratamento térmico a vapor. Para tanto, foram coletadas toras nas classes diamétricas de 25 a 40 cm de três árvores de E. grandis provenientes do Horto Florestal de Mandurí, SP. Em cada uma das toras foram inseridos três termopares, com profundidades distintas, 1/3 do raio; 2/3 do raio e o terceiro, próximo ao seu centro. Posteriormente, as toras foram vaporizadas a 85ºC e 100% de umidade relativa, até que o último termopar atingisse uma temperatura de 80ºC. Um Datalogger CR10 registrou as temperaturas, no interior do material, durante o tratamento térmico. Conclui-se que o modelo matemático logístico foi bem ajustado, obtido no tratamento térmico com vapor, levando em consideração as três classes de diâmetro e a profundidade máxima de 50 mm de raio, o modelo gerado, apresenta-se uma viabilidade técnica na aplicação do processo de aquecimento de toras com vapor, promovendo um consumo ideal de energia.