A fully couple flow of molten steel, heat transfer, and solidification in the mold region of a continuous casting round billet under mold electromagnetic stirring (M-EMS) are investigate with computational tools of fluid flow and electromagnetic simulations. A finite element model is employed to simulate the electromagnetic stirrer in the mold and calculate the Lorenz force distribution. The Lorenz forces are applied as a source term in the Navier-Stokes equations of the fluid flow model, which was solved through a finite volume model. The flow pattern produced by the stirrer is mainly rotational, with velocities of 0.37 m s À1 close to the solidifying shell for the higher current. The results indicate that a higher M-EMS current produces a reduction of the temperature in the strand center; a decrease of 42 8C is observed for a current of 350 A/4.25 Hz. The M-EMS also produces a thinner shell close to the stirrer center and a larger region of solid fraction in the billet center.

An experimental study of the turbulent wake of a wind turbine model was realized at the “Joaquim Blessmann” wind tunnel of the UFRGS. The turbine model was developed at the Universidade de Caxias do Sul and it represents a three blade turbine characterized by a NACA 4412 aerodynamic profile. Measurements of the velocity fluctuations were realized by hot wire anemometry. Complexity of the turbulent flow is evaluated by mean and fluctuating velocity profiles. The influence of the incident flow turbulence and the flow reconstructing process are analyzed by the measurement results.

ResumoA deposição de inclusões (clogging) na válvula submersa e na válvula tampão do distribuidor é um problema que pode ocorrer em todas as aciarias, provocando a interrupção de veios, desestabilização da operação e aumento nos custos. Este trabalho pretende avaliar a influência do escoamento do aço líquido na deposição de inclusões de alumina na válvula tampão. Para isso, é empregado um modelo fluidodinâmico computacional para caracterizar o escoamento do aço na região da válvula tampão. Para o cálculo foi construída uma geometria tridimensional da região próxima à sede. A solução do escoamento e a previsão da deposição de inclusões foram implementadas usando uma formulação euleriana e o modelo lagrangeano, respectivamente. São avaliadas diferentes aberturas da válvula para visualizar o comportamento do aço e relacioná-lo à taxa de deposição de inclusões. Consegue-se observar que ocorre uma recirculação na ponta do tampão e que está relacionada com a abertura da válvula. Observa-se que, quanto maior a abertura da válvula, menor é a taxa de deposição de inclusões. Palavras-chave: Lingotamento contínuo de aço; Válvula tampão; Clogging; CFD. INVESTIGATION OF CLOGGING MECHANISM IN THE STOPPER ROD REGION EMPLOYING CFD ANALYSIS AbstractInclusions deposition on stopper rod and submerged entry nozzle is a problem which may occur in every steel plant, leading to casting interruption, operational instabilities and increase in costs. This paper seeks to analyze the influence of molten steel flow pattern on alumina inclusions deposition at stopper rod. A computational fluid dynamical model is employed in order to characterize the flow in that region. A 3-dimensionalgeometry of the nozzle region was built. Molten steel flow and inclusions deposition are computed through eulerian and lagrangian approaches, accordingly. Different nozzle openings are evaluated in order to visualize the steel flow and to relate alumina deposition rate with it. The results show that there is a recirculation that occurs in the stopper rod tip and it is related to the nozzle openings. It is seen that larger nozzle openings tends to lower the inclusions deposition rate.

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