Convective stability of a particle-laden fluid system in the presence of solidification

In many phase transformation processes, natural convection controls the fre ezing or melting rate of the material. The kinematics of the solid-liquid i nterface, which are coupled with bulk convection in the melt, play an impor tant role in determining the microstructure of a solidified :material. Alth ough the fundamental problem of thermoconvective instability of a single-co mponent in a horizontal liquid layer has been studied extensively, there st ill exist additional complexities which arise during solidification due to the presence of nonmelting components. This study addresses the problem of Rayleigh-Benard instability of a liquid layer in the presence of suspended particles undergoing a phase transformation. A linear stability analysis de termined the effects of the particles and phase-change on the conditions fo r incipient convection. The analysis reveals that the concentration of and heat transfer between particles affect the stability of the system. (C) 200 0 Elsevier Science Ltd. All rights reserved.