University Education: PhD in Engineering Sciences, Universidad Politécnica de Catalunya UPC – Catalunya – EspañaCivil Engineering, Universidad de Buenos Aires UBA – Argentina. Current position: Professor at Universidad de Santiago de Chile USACH, Chile. Area of interest: Computational Fluid Mechanics and Heat Transfer – Dynamic of moving interfaces and free surface flows – Fluid-structure interactions - Vibrations – Numerical methods – Physical models – Modelling, Simulation, and Validation –Work in collaboration: Metal Forming – Material Characterization
The bit–rock interaction is a key point in the fracture process observed in excavation applicatio... more The bit–rock interaction is a key point in the fracture process observed in excavation applications, which makes its analysis relevant. As the discrete element method (DEM) has been successfully applied to study rock breakage behavior, we apply it in the present study to analyze various aspects of the bit–rock interaction. This research focuses on numerically analyzing the bit–rock interaction, encompassing the force penetration relationship (FPR), mechanical energy transfer to the rock, and the efficiency of the mechanical energy transfer process. In order to perform this analysis, we simulate various bit radii and impact velocities. In this study, we establish a power–law function to describe the relationship between the energy transferred to the rock and the force, both as functions of bit penetration. The least-squares method is employed to accomplish this determination. Remarkably, it was observed that the latter aligns with the Hertzian contact law when lower impact velocities...
2021 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2021
This paper proposes three different synergetic control algorithms for two mass models of variable... more This paper proposes three different synergetic control algorithms for two mass models of variable speed wind turbine with wind estimator. The wind turbine is modeled by a two-mass model that deals with wind turbine nonlinear aerodynamics and its flexible models. The controllers aim to maximize the captured energy from the wind whilst reducing the load level of the drive train. Initially, some of the conventional controllers such as sliding mode and integral sliding mode controllers are considered. Nonetheless, these controllers introduce more transient loads. To overcome these issues, a synergetic and terminal synergetic with integral based macro variable are proposed for a two-mass model wind turbine. These proposed controllers are verified through simulation and Fatigue, aerodynamics, structures, and turbulence 600kW model. The simulation results affirm that the terminal synergetic-based integral controller improves transient load reduction than other controllers.
En el presente trabajo se verifica numericamente un nuevo metodo estabilizado de elementos finito... more En el presente trabajo se verifica numericamente un nuevo metodo estabilizado de elementos finitos del tipo multiescalas variacionales (VMS) no-residual y dinamico. El trabajo incluye el analisis de convergencia del metodo en soluciones prefabricadas, utilizando elementos lineales, verificando la tasa de convergencia de los campos de velocidad y presion. Adicionalmente, se resuelven dos problemas tipo, la cavidad cubica accionada por la tapa y el estudio de la dinamica del flujo turbulento en el cuerpo de Ahmed. En el problema de la cavidad cubica accionada por la tapa, se determina el inicio de la bifurcacion de Hopf, ademas de describir la dinamica del problema para un numero de Re=12.000, determinando los espectros (puntuales) de presion y velocidad. En el problema del cuerpo de Ahmed, se resuelve el caso Re=788.000 para diferentes angulos de inclinacion, comprobando los resultados obtenidos con valores de referencia.
En el presente trabajo se evalua el desempeno del modelo de fractura de Mohr-Coulomb Modificado (... more En el presente trabajo se evalua el desempeno del modelo de fractura de Mohr-Coulomb Modificado (MMC) para la determinacion de la Curva Limite de Conformado (FLC) de una lamina de acero DP 780. La descripcion completa del comportamiento del material para conformado contempla la aplicacion de un criterio de fluencia de Hill 48 asociado, una funcion de endurecimiento tipo exponencial y el ya descrito criterio de fractura MMC. Clasicamente, la caracterizacion del modelo plastico se basa en la determinacion de los coeficientes de Lankford para las tres direcciones principales de laminacion (0°, 45° y 90°), y a partir de ellos, se evaluan los coeficientes de anisotropia de Hill los cuales se suponen constantes durante el proceso de deformacion. Dado que la anisotropia del material es una caracteristica evolutiva, estos coeficientes normalmente varian su valor durante el proceso de deformaciones. En este trabajo se estima la variacion de dichos coeficientes con la deformacion a partir de ...
En este trabajo se propone el estudio del problema de agitacion de liquidos en tanques contenedor... more En este trabajo se propone el estudio del problema de agitacion de liquidos en tanques contenedores. Con esta finalidad se realizan modelos fisicos de estanques rectangulares sometidos a cargas ciclicas en una mesa vibradora. De los ensayos se obtiene la evolucion de la posicion de la superficie libre capturadas mediante sensores de nivel por ultrasonido en secciones caracteristicas el recipiente. Los modelos experimentados son simulados numericamente y, en los casos disponibles en la literatura, se obtiene tambien su respuesta analitica. Los casos analizados corresponden a dos profundidades diferentes y a movimientos de agitacion impuestos con distintas amplitudes y frecuencias. Los resultados se validan con las mediciones obtenidas de la experimentacion.
La resolucion de problemas de agitacion de fluidos viscosos y newtonianos con una superficie libr... more La resolucion de problemas de agitacion de fluidos viscosos y newtonianos con una superficie libre en los cuales se simula una unica fase liquida es abordado con una metodologia lagrangiana-euleriana arbitraria que consiste en resolver mediante elementos finitos tres instancias acopladas: las ecuaciones de Navier-Stokes en el fluido, la adveccion de la superficie libre y la deformacion de la malla (L. Battaglia et al., Mecanica Computacional, Vol. XXXVI, p. 2023, 2018). En particular, se evaluara la influencia de la geometria y de las condiciones de borde en la base del tanque en el desempeno del metodo, para lo cual se estableceran comparaciones con resultados de experimentos fisicos y numericos de referencia.
In this work, the fluid dynamics and heat transfer of time-dependent flows with shear-thinning be... more In this work, the fluid dynamics and heat transfer of time-dependent flows with shear-thinning behaviour over two confined square cylinders in tandem arrangement are studied numerically. The case studies include two- and three-dimensional flows under a wide range of power-law indices, $0.25\leq n \leq 1.0$ , and blockage ratios, $\beta =0.50$ , 0.66 and 0.80, for a fixed Reynolds number of $Re=100$ and Prandtl number of $Pr=10$ . The fluid dynamic analysis includes detailed qualitative and quantitative comparisons between the different fluids and blockage ratios, where streamlines, viscosity fields, and lift and drag coefficients are presented. Moreover, a detailed study of the route from laminar time-dependent to chaotic flows is included. It was determined that the flow exhibits a transition from laminar to chaotic by decreasing the power-law index ( $n$ ) and increasing the blockage ratio ( $\beta$ ). With respect to the thermal analysis, isotherms and Nusselt numbers are compare...
The present work reports a comparative study of ductile failure models applied to an Al-2011 alum... more The present work reports a comparative study of ductile failure models applied to an Al-2011 aluminum alloy single-pass wire drawing process using different reductions. The material damage experienced in the wire after passing through the die is evaluated using the well-known Rice and Tracey, Cockcroft and Latham, Brozzo and Modified Chaouadi models. Due to the fact that nonrealistic damage predictions are found for the highest studied wire reduction, an alternative uncoupled failure criterion combining the effect of deformation and triaxility is proposed. The ability of these five models in predicting the formation of chevrons in the process is the main focus of this research. First, the model parameters are characterized by means of numerical simulations of the tensile test. Then, the predictions of the numerical analyses of the drawing process are compared with available experimental results where physical evidence of chevrons was found. Relevant variables are analyzed to determi...
Computer Methods in Applied Mechanics and Engineering, 2016
A Navier–Stokes solver based on Cartesian structured finite volume discretization with embedded b... more A Navier–Stokes solver based on Cartesian structured finite volume discretization with embedded bodies is presented. Fluid structure interaction with solid bodies is performed with an explicit partitioned strategy. The Navier–Stokes equations are solved in the whole domain via a Semi-Implicit Method for Pressure Linked Equations (SIMPLE) using a colocated finite volume scheme, stabilized via the Rhie–Chow discretization. As uniform Cartesian grids are used, the solid interface usually do not coincide with the mesh, and then a second order Immersed Boundary Method is proposed, in order to avoid the loss of precision due to the staircase representation of the surface. This fact also affects the computation of fluid forces on the solid wall and, accordingly, the results in the fluid–structure analysis. In the present work, first and second order approximations for computing the fluid forces at the interface are studied and compared. The solver is specially oriented to General Purpose Graphic Processing Units (GPGPU) hardware and the efficiency is discussed. Moreover, a novel submerged buoy experiment is also reported. The experiment consists of a sphere with positive buoyancy fully submerged in a cubic tank, subject to harmonic displacements imposed by a shake table. The sphere is attached to the bottom of the tank with a string. The position of the buoy is determined from video records with a Motion Capture algorithm. The obtained amplitude and phase curves allow a precise determination of the added mass and drag forces. Due to this aspect the experimental data can be of interest for comparison with other fluid–structure interaction codes. Finally, the numerical results are compared with the experiments, and allow the confirmation of the numerically predicted drag and added mass of the body.
RÉSUMÉ. La technique MLIT (Moving Lagrangian Interface Technique) utilise un maillage fixe pour l... more RÉSUMÉ. La technique MLIT (Moving Lagrangian Interface Technique) utilise un maillage fixe pour la résolution du problème de dynamique des fluides, l'interface entre les deux fluides étant modélisée par un ensemble de marqueurs mobiles. Toutefois, comme un schéma ...
La fusion - solidificacion corresponde quizas al proceso industrial mas utilizado para obtener pi... more La fusion - solidificacion corresponde quizas al proceso industrial mas utilizado para obtener piezas metalicas, siendo indispensable estudiar y controlar la evolucion de las variables involucradas. Se han establecido diversos tipos de modelos para simular la transferencia de calor y la formacion y evolucion de la microestructura, que van desde los modelos analiticos simples en equilibrio hasta modelos numericos de alta complejidad que involucran gran numero de parametros. Sin embargo, estos modelos complejos se han formulado y aplicado especialmente al aluminio con sus aleaciones y a los aceros - fundiciones, dejando de lado al cobre. Este trabajo presenta la simulacion numerica de la solidificacion de cobre anodico (con pureza de 99.83%) colado en diferentes tipos de moldes, donde se estudio la transferencia de calor incluyendo cambio de fase y evolucion microestructural. Se analizo ademas la influencia de la velocidad de extraccion de calor (dada por el material del molde, los cu...
The bit–rock interaction is a key point in the fracture process observed in excavation applicatio... more The bit–rock interaction is a key point in the fracture process observed in excavation applications, which makes its analysis relevant. As the discrete element method (DEM) has been successfully applied to study rock breakage behavior, we apply it in the present study to analyze various aspects of the bit–rock interaction. This research focuses on numerically analyzing the bit–rock interaction, encompassing the force penetration relationship (FPR), mechanical energy transfer to the rock, and the efficiency of the mechanical energy transfer process. In order to perform this analysis, we simulate various bit radii and impact velocities. In this study, we establish a power–law function to describe the relationship between the energy transferred to the rock and the force, both as functions of bit penetration. The least-squares method is employed to accomplish this determination. Remarkably, it was observed that the latter aligns with the Hertzian contact law when lower impact velocities...
2021 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2021
This paper proposes three different synergetic control algorithms for two mass models of variable... more This paper proposes three different synergetic control algorithms for two mass models of variable speed wind turbine with wind estimator. The wind turbine is modeled by a two-mass model that deals with wind turbine nonlinear aerodynamics and its flexible models. The controllers aim to maximize the captured energy from the wind whilst reducing the load level of the drive train. Initially, some of the conventional controllers such as sliding mode and integral sliding mode controllers are considered. Nonetheless, these controllers introduce more transient loads. To overcome these issues, a synergetic and terminal synergetic with integral based macro variable are proposed for a two-mass model wind turbine. These proposed controllers are verified through simulation and Fatigue, aerodynamics, structures, and turbulence 600kW model. The simulation results affirm that the terminal synergetic-based integral controller improves transient load reduction than other controllers.
En el presente trabajo se verifica numericamente un nuevo metodo estabilizado de elementos finito... more En el presente trabajo se verifica numericamente un nuevo metodo estabilizado de elementos finitos del tipo multiescalas variacionales (VMS) no-residual y dinamico. El trabajo incluye el analisis de convergencia del metodo en soluciones prefabricadas, utilizando elementos lineales, verificando la tasa de convergencia de los campos de velocidad y presion. Adicionalmente, se resuelven dos problemas tipo, la cavidad cubica accionada por la tapa y el estudio de la dinamica del flujo turbulento en el cuerpo de Ahmed. En el problema de la cavidad cubica accionada por la tapa, se determina el inicio de la bifurcacion de Hopf, ademas de describir la dinamica del problema para un numero de Re=12.000, determinando los espectros (puntuales) de presion y velocidad. En el problema del cuerpo de Ahmed, se resuelve el caso Re=788.000 para diferentes angulos de inclinacion, comprobando los resultados obtenidos con valores de referencia.
En el presente trabajo se evalua el desempeno del modelo de fractura de Mohr-Coulomb Modificado (... more En el presente trabajo se evalua el desempeno del modelo de fractura de Mohr-Coulomb Modificado (MMC) para la determinacion de la Curva Limite de Conformado (FLC) de una lamina de acero DP 780. La descripcion completa del comportamiento del material para conformado contempla la aplicacion de un criterio de fluencia de Hill 48 asociado, una funcion de endurecimiento tipo exponencial y el ya descrito criterio de fractura MMC. Clasicamente, la caracterizacion del modelo plastico se basa en la determinacion de los coeficientes de Lankford para las tres direcciones principales de laminacion (0°, 45° y 90°), y a partir de ellos, se evaluan los coeficientes de anisotropia de Hill los cuales se suponen constantes durante el proceso de deformacion. Dado que la anisotropia del material es una caracteristica evolutiva, estos coeficientes normalmente varian su valor durante el proceso de deformaciones. En este trabajo se estima la variacion de dichos coeficientes con la deformacion a partir de ...
En este trabajo se propone el estudio del problema de agitacion de liquidos en tanques contenedor... more En este trabajo se propone el estudio del problema de agitacion de liquidos en tanques contenedores. Con esta finalidad se realizan modelos fisicos de estanques rectangulares sometidos a cargas ciclicas en una mesa vibradora. De los ensayos se obtiene la evolucion de la posicion de la superficie libre capturadas mediante sensores de nivel por ultrasonido en secciones caracteristicas el recipiente. Los modelos experimentados son simulados numericamente y, en los casos disponibles en la literatura, se obtiene tambien su respuesta analitica. Los casos analizados corresponden a dos profundidades diferentes y a movimientos de agitacion impuestos con distintas amplitudes y frecuencias. Los resultados se validan con las mediciones obtenidas de la experimentacion.
La resolucion de problemas de agitacion de fluidos viscosos y newtonianos con una superficie libr... more La resolucion de problemas de agitacion de fluidos viscosos y newtonianos con una superficie libre en los cuales se simula una unica fase liquida es abordado con una metodologia lagrangiana-euleriana arbitraria que consiste en resolver mediante elementos finitos tres instancias acopladas: las ecuaciones de Navier-Stokes en el fluido, la adveccion de la superficie libre y la deformacion de la malla (L. Battaglia et al., Mecanica Computacional, Vol. XXXVI, p. 2023, 2018). En particular, se evaluara la influencia de la geometria y de las condiciones de borde en la base del tanque en el desempeno del metodo, para lo cual se estableceran comparaciones con resultados de experimentos fisicos y numericos de referencia.
In this work, the fluid dynamics and heat transfer of time-dependent flows with shear-thinning be... more In this work, the fluid dynamics and heat transfer of time-dependent flows with shear-thinning behaviour over two confined square cylinders in tandem arrangement are studied numerically. The case studies include two- and three-dimensional flows under a wide range of power-law indices, $0.25\leq n \leq 1.0$ , and blockage ratios, $\beta =0.50$ , 0.66 and 0.80, for a fixed Reynolds number of $Re=100$ and Prandtl number of $Pr=10$ . The fluid dynamic analysis includes detailed qualitative and quantitative comparisons between the different fluids and blockage ratios, where streamlines, viscosity fields, and lift and drag coefficients are presented. Moreover, a detailed study of the route from laminar time-dependent to chaotic flows is included. It was determined that the flow exhibits a transition from laminar to chaotic by decreasing the power-law index ( $n$ ) and increasing the blockage ratio ( $\beta$ ). With respect to the thermal analysis, isotherms and Nusselt numbers are compare...
The present work reports a comparative study of ductile failure models applied to an Al-2011 alum... more The present work reports a comparative study of ductile failure models applied to an Al-2011 aluminum alloy single-pass wire drawing process using different reductions. The material damage experienced in the wire after passing through the die is evaluated using the well-known Rice and Tracey, Cockcroft and Latham, Brozzo and Modified Chaouadi models. Due to the fact that nonrealistic damage predictions are found for the highest studied wire reduction, an alternative uncoupled failure criterion combining the effect of deformation and triaxility is proposed. The ability of these five models in predicting the formation of chevrons in the process is the main focus of this research. First, the model parameters are characterized by means of numerical simulations of the tensile test. Then, the predictions of the numerical analyses of the drawing process are compared with available experimental results where physical evidence of chevrons was found. Relevant variables are analyzed to determi...
Computer Methods in Applied Mechanics and Engineering, 2016
A Navier–Stokes solver based on Cartesian structured finite volume discretization with embedded b... more A Navier–Stokes solver based on Cartesian structured finite volume discretization with embedded bodies is presented. Fluid structure interaction with solid bodies is performed with an explicit partitioned strategy. The Navier–Stokes equations are solved in the whole domain via a Semi-Implicit Method for Pressure Linked Equations (SIMPLE) using a colocated finite volume scheme, stabilized via the Rhie–Chow discretization. As uniform Cartesian grids are used, the solid interface usually do not coincide with the mesh, and then a second order Immersed Boundary Method is proposed, in order to avoid the loss of precision due to the staircase representation of the surface. This fact also affects the computation of fluid forces on the solid wall and, accordingly, the results in the fluid–structure analysis. In the present work, first and second order approximations for computing the fluid forces at the interface are studied and compared. The solver is specially oriented to General Purpose Graphic Processing Units (GPGPU) hardware and the efficiency is discussed. Moreover, a novel submerged buoy experiment is also reported. The experiment consists of a sphere with positive buoyancy fully submerged in a cubic tank, subject to harmonic displacements imposed by a shake table. The sphere is attached to the bottom of the tank with a string. The position of the buoy is determined from video records with a Motion Capture algorithm. The obtained amplitude and phase curves allow a precise determination of the added mass and drag forces. Due to this aspect the experimental data can be of interest for comparison with other fluid–structure interaction codes. Finally, the numerical results are compared with the experiments, and allow the confirmation of the numerically predicted drag and added mass of the body.
RÉSUMÉ. La technique MLIT (Moving Lagrangian Interface Technique) utilise un maillage fixe pour l... more RÉSUMÉ. La technique MLIT (Moving Lagrangian Interface Technique) utilise un maillage fixe pour la résolution du problème de dynamique des fluides, l'interface entre les deux fluides étant modélisée par un ensemble de marqueurs mobiles. Toutefois, comme un schéma ...
La fusion - solidificacion corresponde quizas al proceso industrial mas utilizado para obtener pi... more La fusion - solidificacion corresponde quizas al proceso industrial mas utilizado para obtener piezas metalicas, siendo indispensable estudiar y controlar la evolucion de las variables involucradas. Se han establecido diversos tipos de modelos para simular la transferencia de calor y la formacion y evolucion de la microestructura, que van desde los modelos analiticos simples en equilibrio hasta modelos numericos de alta complejidad que involucran gran numero de parametros. Sin embargo, estos modelos complejos se han formulado y aplicado especialmente al aluminio con sus aleaciones y a los aceros - fundiciones, dejando de lado al cobre. Este trabajo presenta la simulacion numerica de la solidificacion de cobre anodico (con pureza de 99.83%) colado en diferentes tipos de moldes, donde se estudio la transferencia de calor incluyendo cambio de fase y evolucion microestructural. Se analizo ademas la influencia de la velocidad de extraccion de calor (dada por el material del molde, los cu...
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