NUMERICAL MODELING OF THE INTERACTION OF PARTICLES WITH SOLIDIFYING INTERFACES

摘要

The thermal field of a moving solidification interface towards a spherical particle was dynamically modeled in order to study the deformation of the interface in relation with different thermal properties of particle and matrix. Finite element methods were employed in an axi-symmetric model of the system. The degree of deformation when the particle has a different thermal conductivity than the matrix is presented and discussed. The drag force on a particle being pushed by a crystal was calculated with a fluid flow model. The force was calculated for different pushing configurations and the results compared with the values given by the modified Stokes equation; which show that the model values are slightly larger than those calculated with the equation. This difference predicts an equilibrium separation for pushing lower than that calculated using the modified Stokes equation when a Lifshitz-Van der Waals model of repulsion force is used