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Search Results: 1 - 10 of 472562 matches for " Miguel A. Barron "
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Internal Vibration and Synchronization of Four Coupled Self-Excited Elastic Beams  [PDF]
Miguel A. Barron
Open Journal of Applied Sciences (OJAppS) , 2016, DOI: 10.4236/ojapps.2016.68050
Abstract: The vibration behavior and the synchronization between some internal points of four coupled self-excited beams are numerically studied. Coupling through the root of the beams is considered. The transverse displacements of the internal points and the beam tips are monitored, and the power spectra of the resulting time series are employed to determine the oscillation frequencies. The synchronization between beams is analyzed using phase portraits and correlation coefficients. Numerical results show multiple frequencies in the vibration pattern, and complex patterns of synchronization between pairs of beams.
Numerical Simulation of an Argon Stirred Ladle with Top and Bottom Injection  [PDF]
Sofia Torres, Miguel A. Barron
Open Journal of Applied Sciences (OJAppS) , 2016, DOI: 10.4236/ojapps.2016.613075
Abstract: The stirring of a molten steel ladle with argon injection through a top submerged lance and a bottom nozzle is numerically studied here through Computational Fluid Dynamics (CFD) simulations. Three lance submergence depths and three injection velocities are considered in the CFD numerical experiments. The turbulent dissipation rate is employed to characterize the stirring phenomenon. The mixing times are determined from the gas flow rate, ladle geometry and bath depth using an empirical correlation.
A Feedforward Controller to Regulate the Chemical Composition of Molten Steel in a Continuous Casting Tundish  [PDF]
Miguel A. Barron, Dulce Yolotzin, Isaias Hilerio
Intelligent Control and Automation (ICA) , 2013, DOI: 10.4236/ica.2013.43029
Abstract:

A feedforward controller for the automatic regulation of chemical composition of molten steel in the tundish of a continuous casting machine is proposed in this work. The flow of molten steel inside the tundish is modeled as a distributed parameter system, and the resulting partial differential equation is transformed into a set of ordinary differential equations by means of the finite differences technique. From the above set and using a proper boundary condition, a feedforward control law is synthesized. No experimental tests are reported, however, the dynamic performance of the controller is illustrated by means of numerical simulations.

Numerical Analysis of Slag Carry-Over during Molten Steel Draining  [PDF]
Daniel Flores-Sanchez, Miguel A. Barron
Open Journal of Applied Sciences (OJAppS) , 2017, DOI: 10.4236/ojapps.2017.711044
Abstract: Slag carry-over during the draining of molten steel from a teeming ladle is numerically studied here. Two-phase isothermal transient 3D Computational Fluid Dynamics simulations were employed to simulate the draining process. Two nozzle diameters, two nozzle positions and three slag heights were considered. From mass balances, the slag carry-over in terms of mass flow rate was obtained for each of the above variables. Besides, the draining times of the teeming ladle were estimated from theoretical considerations and CDF simulations, and compared.
Anchor-Shaped Design of a Submerged Entry Nozzle for the Continuous Casting of Steel  [PDF]
Carlos A. Hernandez, Miguel A. Barron, Raul Miranda
Open Journal of Applied Sciences (OJAppS) , 2016, DOI: 10.4236/ojapps.2016.69058
Abstract: An anchor-shaped geometrical design for a Submerged Entry Nozzle for the slab continuous casting of steel is presented in this work. To evaluate its performance, transient 3D multiphase numerical simulations were carried out using the Computational Fluid Dynamics technique. The performance of the proposed nozzle is numerically compared with that of a conventional cylindrical nozzle. Computer results show that the chance of formation of Karman’s vortexes and powder entrapment becomes small for the anchor-shaped SEN.
Nitrogen Injection in Molten Aluminum in a Tank Degasser  [PDF]
Luis A. Maldonado, Miguel A. Barron, Dulce Y. Miranda
World Journal of Engineering and Technology (WJET) , 2018, DOI: 10.4236/wjet.2018.64044
Abstract: The injection of nitrogen in molten aluminum through a static impeller in a tank degassing unit is studied. Using basic principles of fluid mechanics, it is analyzed the influence of the nozzle diameter on the bubble diameter and the mean residence time of the bubbles in the molten aluminum. By means of transient isothermal 2D Computational Fluid Dynamics (CFD) simulations, the influence of the nitrogen volumetric flow rate on the phase distributions and the tank degasser dynamics is studied. Finally, an adiabatic CFD simulation is carried out in order to elucidate the changes in the molten aluminum temperature due to the injection of nitrogen at ambient temperature. This simulation shows that molten aluminum does not suffer drastic temperature reductions given that, in spite?that?the nitrogen is fed at ambient temperature, the mass of nitrogen is relatively small compared with the mass of aluminum.
CFD Analysis of Influence of Slag Viscosity on the Splashing Process in an Oxygen Steelmaking Converter  [PDF]
Miguel A. Barron, Dulce Y. Medina, Isaias Hilerio
Modeling and Numerical Simulation of Material Science (MNSMS) , 2013, DOI: 10.4236/mnsms.2013.33012
Abstract: Physical properties of molten slag such as viscosity, density and surface tension have a significant influence on the slag splashing process in an oxygen steelmaking converter. Particularly, viscosity determines the shear forces that rule droplets formation. Besides, stirring of the molten slag bath strongly depends on this property. In this work, the influence of viscosity on the efficiency of slag splashing is explored by means of transient Computational Fluid Dynamics simulations. Several values of viscosity are employed in the computer experiments. In order to quantify the splashing efficiency as function of slag viscosity, an average slag fraction on the converter walls is defined and calculated. CFD results are compared with those of an empirical expression, and at least qualitative agreement is found.
Collective Behavior of a Ring of Van Der Pol Oscillators under Gaussian and Random Coupling Schemes  [PDF]
Miguel A. Barron, Dulce Y. Medina, Isaias Hilerio
Open Journal of Applied Sciences (OJAppS) , 2014, DOI: 10.4236/ojapps.2014.47036
Abstract: The collective behavior of a ring of coupled identical van der Pol oscillators is numerically studied in this work. Constant, gaussian and random distributions of the coupling parameter along the ring are considered. Three values of the oscillators constant are assumed in order to cover from quasilinear to nonlinear dynamic performance. Single and multiple coupled frequencies are obtained using power spectra of the long term time series. Phase portraits are obtained from numerical simulations, and the coupled behavior is analyzed, compared and discussed.

Regulation of the Reacted Layer Thickness in a Gas-Solid Reacting System  [PDF]
Miguel A. Barron, Dulce Y. Medina, Gabriel Plascencia
Intelligent Control and Automation (ICA) , 2014, DOI: 10.4236/ica.2014.53010
Abstract:

A mathematical model for the analysis of a gas-solid reacting system is presented. This model is an alternative to the classical shrinking-core model. The model has a structure that can be easily transformed into a canonical control form, which is proper for controller synthesis. Analytical solution of the model to describe the open-loop behavior is expressed in terms of the Lambert function. The Lambert function is evaluated from aTaylorexpansion series. Besides, a controller is proposed to regulate the reacted layer thickness using initially the diffusion coefficient as control input. The control law is synthesized employing the feedback linearization technique. Main contributions of this work are the synthesis of the layer thickness controller, and the employment of the process temperature as substitute of the diffusion coefficient as the control input.

Numerical Simulation of Decarburization in a Top-Blown Basic Oxygen Furnace  [PDF]
Miguel A. Barron, Dulce Y. Medina, Isaias Hilerio
Modeling and Numerical Simulation of Material Science (MNSMS) , 2014, DOI: 10.4236/mnsms.2014.43011
Abstract:
An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.
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