A finite element formulation for incompressible flow problems using a generalized streamline operator

A finite element formulation for solving incompressible flow problems is presented. In this paper, the generalized streamline operator presented by Hughes et al. (Comput. Methods Appl. Mech. Engrg. (1986) 58 305-328) for compressible flows is adapted to the incompressible Navier-Stokes equations. This new methodology allows the use of equal order interpolation for the unknowns of the problem: velocity and pressure. In this context, the definition of the ‘upwinding tensor’ does not require parameters defined outside this model. This formulation has been checked in classical tests with satisfactory results. Finally, a moving surface problem (Cruchaga et al., Comput. Numer. Methods Engrg. (1986) 59: 85-99) is also presented.&nbsp

A generalized streamline finite element approach for the analysis of incompressible flow problems including moving surfaces

In the present work a generalized streamline finite element formulation able to deal with incompressible flow problems is presented. In the finite element framework, this technique allows the use of equal order interpolation for the unknowns of the problem: velocity and pressure. In this context, stable and convergent solutions can be obtained without requiring tuning parameters defined outside this model. The tracking of moving surfaces is also included in the numerical model. This formulation has been checked in 21) and 3D tests

Aplicaciones de Mecánica Computacional en la industria sidero-metalúrgica

En el presente trabajo se presentan aplicaciones de Mecánica Computacional en el ámbito de la industria sidero metalúrgica . Las aplicaciones que se presentan pueden ser divididas en : análisis de procesos de fabricación y análisis de la performance en servicio de productos siderúrgicos. En el primer caso el objetivo del modelado computacional es la optimización de procesos productivos y, en el segundo caso, el objetivo es la evaluación de la prestación que puede esperarse de diversos productos siderúrgicos, en particular se ha analizado la performance de tubos de acero sin costura para aplicaciones petroleras.Peer Reviewe

Aplicaciones de Mecánica Computacional en la industria sidero-metalúrgica

En el presente trabajo se presentan aplicaciones de Mecánica Computacional en el ámbito de la industria sidero metalúrgica . Las aplicaciones que se presentan pueden ser divididas en : análisis de procesos de fabricación y análisis de la performance en servicio de productos siderúrgicos. En el primer caso el objetivo del modelado computacional es la optimización de procesos productivos y, en el segundo caso, el objetivo es la evaluación de la prestación que puede esperarse de diversos productos siderúrgicos, en particular se ha analizado la performance de tubos de acero sin costura para aplicaciones petroleras.Peer Reviewe

NUMERICAL FORECAST OF THE MELTING AND THERMAL HISTORIES OF PARTICLES INJECTED IN A PLASMA JET

18 pagesThis work presents the numerical simulation of the melting process of a particle injected in a plasma jet. The plasma process is nowadays applied to produce thin coatings on metal mechanical components with the aim of improving the surface resistance to different phenomena such as corrosion, temperature or wear. In this work we studied the heat transfer including phase-change of a bi-layer particle composed of a metallic iron core coated with ceramic alumina, inside a plasma jet. The model accounted for the environmental conditions along the particle path. The numerical simulation of this problem was performed via a temperature-based phase-change finite element formulation. The results obtained with this methodology satisfactorily described the melting process of the particle. Particularly, the results of the present work illustrate the phase change evolution in a bi-layer particle during its motion in the plasma jet. Moreover, the numerical trends agreed with those previously reported in the literature and computed with a finite volume enthalpy based formulation

Experimental and numerical analysis of a sphere falling into a viscous fluid

The experimental and numerical analysis of spheres falling into viscous flows is considered. The physical model is built using a set of silicone and glass spheres falling into oil and water. The rigid‐body trajectory of the sphere and the free surface evolution are obtained from videos. The numerical results are obtained using two different finite element codes. The first code uses a fractional step approach with adaptive meshes and time‐step sizes whereas the second code uses a monolithic fully coupled fixed‐mesh technique. The results exhibit a good comparison between both numerical techniques and with the experiments

Experimental and numerical analysis of effect of cooling rate on thermal–microstructural response of spheroidal graphite cast iron solidification

This work presents an experimental and numerical study of the solidification process of an eutectic spheroidal graphite cast iron (SGI). The effect of the cooling rate on the thermal–microstructural response is particularly analysed. To this end, experiments as well as numerical simulations were carried out. The experiments consisted in a solidification test in a wedge-like casting such that different cooling rates were measured at specific positions along the part. A metallographic analysis was also performed in five locations of the sample with the aim of obtaining the number and size of graphite nodules at the end of the process. The numerical simulations were made using multinodular based and uninodular based models. These two models predicted similar results in terms of cooling curves and nodule counts. Besides, good experimental–numerical agreements were obtained for both the cooling curves and the graphite nodule counts

Predicción de fractura en alambres trefilados en una pasada

Un problema recurrente en el proceso de trefilado de alambres es la aparición de una microcavidad interna conocida como “estallido central” la que puede crecer hasta cortar el alambre, obligando a detener el proceso. En este trabajo se presenta un estudio numérico del proceso de trefilado de alambres de una aleación de aluminio Al-2011, con la intención de evaluar la evolución de las variables internas (deformación plástica efectiva y triaxialidad) y su incidencia en el desarrollo de la fractura de los alambres trefilados en una pasada. La caracterización del material y del criterio de fractura usado en el presente trabajo se realiza mediante un ensayo de tracción uniaxial y los parámetros obtenidos se utilizan en simulaciones numéricas de 6 configuraciones geométricas distintas: el ángulo de la hilera se mantiene constante y el diámetro inicial del alambre aumenta gradualmente para tener 6 niveles de reducción distintos. La validación se realiza mediante el análisis de la fuerza de tiro de estas mismas mediciones experimentales reportadas en la literatura. Al final de este trabajo se presenta un mapa de zonas seguras e inseguras, según los resultados obtenidos del criterio de fractura para las configuraciones geométricas estudiadas.Publicado en: Mecánica Computacional vol. XXXV no.35Facultad de Ingenierí

Viscoplastic and temperature behavior of Zn–Cu–Ti alloy sheets: experiments, characterization, and modeling

It has been experimentally observed that the Zn–Cu–Ti zinc alloy shows a strong influence of strain rate and temperature on its plastic behavior. A significant change in the material response is seen with relatively small strain rate variations or temperature. In this work, these effects are addressed through the Cazacu–Plunket–Barlat 2006 (CPB-2006) yield criterion and the Johnson–Cook hardening law. The tests were carried out over the three main directions: rolling, diagonal, and transversal. Three strain rate conditions (0.002, 0.02, and 0.2 s−1) and three temperatures (20, 60, and 80 °C) were tested. Although the experimental results exhibit a significant influence of the strain rate and temperature on stress–strain curves for all tested directions, such two variables do not practically affect the Lankford coefficients. The proposed model calibration procedure is found to describe the material responses properly under the studied conditions.Fil: Alister, Francisco. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Celentano, Diego Javier. Pontificia Universidad Católica de Chile; Chile. Universidad Católica de Chile; ChileFil: Signorelli, Javier Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Bouchard, Pierre Olivier. Ecole Des Mines de Paris; FranciaFil: Pino Muñoz, Daniel. Ecole Des Mines de Paris; FranciaFil: Cruchaga, Marcela. Universidad de Santiago de Chile; Chil