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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6 resultados
Resultados da Pesquisa
Item Analysis of the fluid flow behavior within a beam blank mold using submerged-entry nozzle with three exit ports.(2019) Gabriel, Weslei Viana; Peixoto, Johne Jesus Mol; Alves, Gesiane Letícia; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, VaradarajanThrough the use of physical and mathematical modeling techniques, liquid flow inside a beam blank mold with a submerged valve consisting of three exit ports has been analyzed. The behavior of the slag metal interface was evaluated using water and an aqueous NaCl solution to simulate steel. Slag simulation was done using silicon oil. Increased casting speed results in increased free surface oscillation. For the fluid density of 1,000 kg/m3, oil entrainment started at a casting velocity of 0.98 m/minute. For a fluid density of 1,170 kg/m3, no entrainment was observed in any of the conditions studied.Item Numerical and physical simulation of the fluid flow in a beam blank mold fed through the center of the web.(2019) Gabriel, Weslei Viana; Peixoto, Johne Jesus Mol; Queiroz, Guilherme Santiago; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, VaradarajanFluid flow inside a beam blank mold fed through a three-port SEN (two lateral ports and one bottom port), positioned at the center of the mold, has been investigated. Literature survey shows that this kind of configuration is not frequently used. It had been shown that it is possible to get a symmetrical flow with this configuration. The downward inclination of the ports should influence the transient fluid flow. The greater the downward inclination, the greater is the instability of the jet and of the interface between the immiscible fluids that simulate the slag/metal behavior. The flow characterization was made by dye dispersion, PIV technique, measurement of the meniscus oscillation using ultrasonic sensors, and CFD simulations. The slag/metal behavior was simulated using water and oils with different physical properties. The results from PIV as well as from observations of the water–oil interface have been used to validate the CFD simulations. Oils with density close to water resulted in more instability at the interface with entrainment starting from fluid flow rate of 125 L/min (equivalent to casting speed of 1 m/min). Decreasing the viscosity of slag (oils) and increasing the casting velocity (water flow rate) result in reduction of the interfacial stability.Item Numerical simulation of recirculating flow and physical model of slag–metal behavior in an RH reactor : application to desulfurization.(2018) Peixoto, Johne Jesus Mol; Gabriel, Weslei Viana; Oliveira, Thiago Araújo Santos de; Silva, Carlos Antônio da; Silva, Itavahn Alves da; Seshadri, VaradarajanComputational fluid dynamics (CFD) techniques and a 1:7.5 physical model of an RH degasser have been used to evaluate the flow of gas and metal inside an RH reactor for vacuum degassing of liquid steel. The effect of gas injection on the gas spatial distribution, steel circulation rate and flow field inside the ladle, snorkels and vacuum chamber have been assessed. N-pentane oil was employed to evaluate the average residence time as well as the slag droplet size distribution. The predicted radial gas distribution and liquid circulation rate have been validated against experimental data from a physical model. The results with incorporation of the virtual mass force coefficient of 0.25 and the turbulence dispersion force showed better predictions of gas distribution in the up-snorkel as well as circulation rate. Full-scale simulations were performed, and the predicted circulation rate was significantly affected by the argon bubble expansion. Data from these simulations were used to analyze the degree of desulfurization performed by the addition of desulfurizing agents inside the vacuum chamber. A model of the kinetics of desulfurization based on the results from the physical model and CFD simulation and on slag dispersion inside liquid steel yields degrees of desulfurization similar to the industrial trials reported in the literature.Item 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, VaradarajanUtilizando 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.Item 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, VaradarajanA 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.Item 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, VaradarajanThe 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.