DECAT - Departamento de Controle e Automação
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/490
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2 resultados
Resultados da Pesquisa
Item Numerical analysis of the liquid ejection due to the gaseous jet impact through computational fluid dynamics.(2018) Araújo, Hiuller Castro; Rodrigues, Eliana Ferreira; Leal, Elisângela MartinsMetal droplets generated by an impinging jet, play an important role in metal refining processes, mainly in oxygen steelmaking, where the droplets are ejected into the slag phase. Since the available interfacial area of droplets is very high in this process, the generated droplets enhance the rates of heat transfer and chemical reactions. Therefore, knowledge of the metal droplet generation rate, size distribution and residence time in the slag are of industrial relevance. In this work, the isothermal, transient flow of an incompressible air jet impinging onto an air/water interface at room temperature has been simulated to obtain a better understanding of the droplet ejection phenomenon. The interface was tracked throughout time using the volume of fluid (VOF) technique. The governing equations formulated for mass and momentum conservation and the k-e turbulence model are solved in the axisymmetric computational domain using the commercial code FLUENT. The droplet ejection rates calculated with computational fluid dynamics model are compared to experimental data reported in literature, showing partial agreement, being the incompressibility assumption the probable reason for the deviation observed, which was as far pronounced as the great jet velocity. Nevertheless, the model presented shows itself as a relatively good starting point for the construction of more complex ones (with less simplifying assumptions) which should be able to offer a means to increase the understanding of the droplet ejection phenomena.Item Experimental and numerical analysis of a naturally ventilated double-skin façade.(2018) Souza, Leonardo Carvalho Oliveira de; Souza, Henor Artur de; Rodrigues, Eliana FerreiraThis paper investigates the efficiency of a naturally ventilated double-skin façade (DSF) built in a test cell focusing on the airflow and heat convection of the cavity formed by DSF. The study covers measurements of the test cell and their numerical simulation. DSFs have been widely researched worldwide, since they contribute to the thermal performance of the internal environment and to energy savings by eliminating mechanical conditioning systems. For data acquisition, type K surface thermocouples are installed on the wall faces of the test cell and the additional façade, that is, on the inner and outer face of the wall of the test cell and the inner face of the external one. Furthermore, hot wire anemometers are positioned so as to obtain the air velocity in the lower and upper openings of the cavity, which has an air layer thickness of 0.1 m. The results show that the DSF presence contributes to a decrease of the temperature inside the environment because it inhibits the direct solar radiation. Measurement of the faces shows that at 4:00 p.m. the temperature reaches their maximum values. These values are equal to 25.6°C on the inner face of the façade and 23.6°C on the inner face of the test cell, while the outdoor temperature presents values equal to 23.1°C at this time.