Simulation numérique du couplage électrique, thermique et mécanique lors du frittage « flash » de matériaux céramiques et métalliques

Le procédé de frittage « flash » ou SPS (Spark Plasma Sintering) est utilisé comme procédé de consolidation de matériaux céramiques ou métalliques. Une simulation numérique des couplages électrique, thermique et mécanique lors du traitement « SPS » a été menée. Les équations caractéristiques de la conservation de l'énergie, du potentiel électrique et les équations d'équilibre, pour le comportement mécanique, sont résolues simultanément et des couplages forts, en terme de température, sur les coefficients de conductivité thermique et de résistivité électrique sont pris en compte. Les exemples d'application concernent des échantillons céramiques (alumine) ou métalliques (cuivre)

Numerical simulation of convective flows occuring during AL-4.1WT%CU solidification

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.This study presents a numerical simulation of the convective laminar flow, driven by combined thermo-solutally buoyancy forces, under a uniform horizontally applied magnetic field, held during the solidification of a molten alloy Al- 4.1wt%Cu filled in a rectangular cavity. The continuum model, of Bennon and Incropera [1], was used in the development of the mathematical model, representing the solidification phenomena. Following this model, the alloy solidification process is governed by continuity, Navier-Stokes, energy, species and electrical potential conservation equations. Here solved by using finite volume method. The effect intensity of the magnetic field on convective flow has been investigated. The governing equations are firstly non-dimensionalized and are approximated by using a finite volume method.cs201

Modelling of combined Benard and Marangoni convection flow in a low prandtl number material filled in a square mold

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MODELLING ON THERMO-SOLUTAL CONVECTIVE FLOW DURING DIRECTIONAL SOLIDIFICATION OF A SEMICONDUCTOR

International audienceIn the present paper a problem on combined thermo-solutal buoyancy forces driven flow in Pb- 10wt%Sn semiconductor system filled in a rectangular enclosure has been investigated by numerical simulation. Continuum model for solidification modeling is used. Generated flow under thermal and solutal buoyancy forces is laminar but could be, under an increase in the thermal gradient, turbulent or transition to turbulent in nature. External forces such Lorentz force (due to applied magnetic field) are recommended for controlling and stabilizing the flow. Knowledge of interaction among these forces is important to study the effect of flow on heat rate related to the melt

Study of Macrosegregation Defects Formation Caused by Double Diffusive Convective Flow during Solidification of a Binary Alloy

International audienceNumerical study of both the solidification of the binary alloy Al-4.1%wtCu and macrosegregation defects formation have been carried out. The mixture continuum model was used in the development of the mathematical model representing the solidification phenomena. This model included the conservative equations (mass, momentum, energy and species); these equations were numerically solved by using a finite volume approach

Numerical Simulation Study for the Effect of the Strength and the Direction of a Static Magnetic Field on the Transient Double-Diffusive Flow in Liquid Phase during an Alloy Solidification

International audienceA numerical simulation study has been carried out to examine the effect of a static magnetic field on the solidification process of an alloy. A mathematical model, based on the continuum model, was developed for the computation of a transient double-diffusive fluid flow under Lorentz body force. The model includes conservation of mass and momentum, heat, species and electrical charge balance equations. The simulation domain was selected as a cavity filled with a metallic alloy and differentially heated, which may be taken as a Bridgman model domain used in the crystal growth process. The solution is carried out by using a Finite Volume Method. Study of the direction and the intensity of the applied magnetic field effects on stabilizing the double diffusive flow field were also carried out. Simulation results indicate that the use of a static, magnetic field in this growth setup is effective in suppressing natural convection in the solution

Finite Element Modeling of Silicon Transport into Germanium Using a Simplified Crystal Growth Technique

International audienceA numerical simulation study, using finite element method, was carried out to examine the temperature and concentration fields in the dissolution process of silicon into germanium melt. This work utilized a simplified configuration which may be considered to be similar material configuration to that used in the Vertical Bridgman growth methods. The concentration profile for the Si-Ge sample processed using this technique shows increasing transport silicon into the melt with time, moreover, a flat stable interface is observed. The mass and momentum equations for fluid flow, the energy and the solute mass transport were numerically solved. Results showed good agreements with experiments