Modelling of the interaction of particles with non-planar solidifying interfaces,

AGALIOTIS, E. M.; MARIO ROBERTO ROSENBERGER; SCHVEZOV, C. E.; ARES, A.E.

Vancouver, Canada

Congreso; MCWASP XII; 2009

The interaction of a foreign particle with a solidifying interface is studied with numerical modelling. The model include two main forces;the drag and the pushing forces. The drag force is calculated from the fluid flow the Lifshitz-Van der Waal force. The thermal field isuncoupled from the force field. The model is applied to a metallic matrix and particles with similar and smaller thermal conductivities;giving planar and concave interface shapes respectively. The steady state of pushing is reached for the same conditions and differentsolidification velocities and temperature gradients.The results show that a concave interface shape generate higher drag forces about one order the magnitude higher than those for aplanar interface. As a result the critical velocity is less than that corresponding to a planar interface for the same particle radius.Themagnitude of the effect of the different parameters in the phenomenon is presented and discussed.