EM - Escola de Minas

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/6

Notícias

A Escola de Minas de Ouro Preto foi fundada pelo cientista Claude Henri Gorceix e inaugurada em 12 de outubro de 1876.

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Resultados da Pesquisa

Agora exibindo 1 - 4 de 4
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    Bubble behavior in the slab continuous casting mold : physical and mathematical model.
    (2020) Santos Júnior, Paulo Luiz; Peixoto, Johne Jesus Mol; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Galinari, Clenice Moreira
    A two-phase population balance is used to predict the polydispersed bubble flow and size distribution in a slab continuous casting mold and Submerged Entry Nozzle (SEN) system. Multiple Size Group (MUSIG) with a suitable breakage and coalescence model (Ansys CFX) was adopted to account for the polydispersed gas flow. Initial bubble size distribution as determined for two industrial refractories have been taken in consideration. A two way coupling model including the effect of the drag force and non-drag forces such as virtual mass force and turbulent dispersion force was considered. The results are compared with gas distribution in a 1:1 scale water — air mold model running under conditions of fluidynamic similarity to validate the model. The simulations have then been extended to describe the actual steel — argon flow, considering a thermal expansion factor for argon bubbles. The effect of gas distribution on the flow field of liquid inside the mold and other metallurgical aspects are discussed.
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    Influência da configuração da SEN no comportamento fluidodinâmico em molde de Beam Blank.
    (2017) Gabriel, Weslei Viana; Peixoto, Johne Jesus Mol; Alves, Gesiane Letícia; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, Varadarajan
    Utilizando técnicas de modelagem física e matemática comparou-se o fluxo de fluido no interior do molde de beam blank alimentado por apenas uma válvula submersa, com 3 e 4 portas na saída respectivamente. Na válvula com 4 portas, observou-se que para um diâmetro da porta de saída inferior de 10mm não houve alterações significativas no comportamento do fluxo, comparado à válvula com apenas três portas laterais. Ao aumentar o diâmetro para 16mm, houve alteração significativa do perfil de velocidade, reduzindo a assimetria de fluxo, fato que pode contribuir para a redução no gradiente térmico ao longo do molde, diminuindo a possibilidade de ocorrência de defeitos no material lingotado. Com o aumento da dimensão da porta inferior observou-se também redução na velocidade de impacto do jato principal e consequentemente reduziu-se a velocidade do fluxo ascendente, o que evita refusão da pele e entranhamento de escória.
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    The influence of the geometry of a three orifice nozzle on the flowfield inside a beam blank mold.
    (2017) Gabriel, Weslei Viana; Peixoto, Johne Jesus Mol; Silva, Ciro Azevedo; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, Varadarajan
    A single nozzle design with three lateral ports has been proposed to feed a beam blank mold. Techniquesof physical modeling and computational fluid dynamics (CFD) were applied to evaluate the fluid flowas a function of port angle, immersion depth and flow rate. The overall features of the flow field are notaffected by changing the values of these parameters. The proposed design is characterized by: increasingfluctuation intensity at the meniscus and high impact velocities in certain regions of the broad face of theflanges. The oscillation intensity increases with decreasing immersion depth, increasing inclination of theexit ports, and increasing flow rates. These values vary also along the free surface of the mold, being largeron the flange opposite to the submerged entry nozzle (SEN) for all configurations. The impact velocitiesat the flange were affected only by the flow rate, reaching a maximum value of 0.45 m/s.
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    Computational and physical simulation of fluid flow inside a beamblank continuous casting mold.
    (2016) Peixoto, Johne Jesus Mol; Gabriel, Weslei Viana; Ribeiro, Leticia Queiroz; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, Varadarajan
    The main features of the flow field inside a beam blank continuous casting mold have been assessedthrough mathematical and physical modeling techniques. Experimental techniques such as particle dis-persion through addition of dye and particle image velocimetry have been used in a physical model of themold to assess the flow pattern. Different combinations of nozzle geometry and throughput have beenemployed and the experimental results have been analyzed. In the case of two tubular nozzles, whichshould ensure good thermal and flow symmetry, six vortices were observed in the mold, two near theweb and two in each of the flanges. Increasing the flow rate of the fluid from 100 L/min to 150 L/minleads to a change from 0.74 m to 0.84 m in the jet penetration depth. However even a 67% increase ofthe nozzle cross section did not affect this parameter significantly. Experiments with one single tubularnozzle (53.2 mm inside diameter) were also carried out and the resulting flow asymmetry has been char-acterized. The difference in the fluid velocities at the filets could lead to unequal solid shell growth. Thedepth of jet penetration is larger than mold nominal length (0.8 m). Fluid flow structure as determinedby PIV measurements and CFD simulations show a good agreement.