MONTE CARLO SIMULATION OF GROWTH OF SOLID UNDER FORCED FLUID FLOW

摘要

Solidification under intense convection appears to deviate from that under quiescent condition. Most important effect is increased particle refinement and non-dendritic morphology. Despite such interesting observation and the potential for commercial exploitation, solidification under forced convection is relatively less understood. A detailed Monte Carlo simulation has been performed to understand microstructure formation under intense forced convection considering simultaneous atomic transportation in the bulk liquid, atom attachment kinetics at the solid-liquid interface and capillary effect. Evolution of solid morphology and the growth kinetics is studied under both static (purely diffusive) and melt flow (laminar and turbulent flow) conditions. It is clearly indicated that morphological evolution under intense convection is purely a growth phenomena resulting from the effect of forced fluid flow on the diffusion layer geometry around the growing solid. While increased intensity of the forced convection promotes microstructural coarsening, the nature of the flow appears to be more influential on the evolution of the solid morphology.