Rayleigh-Benard convection during solidification of an eutectic solution cooled from the top

Kumar, P and Chakraborty, S and Srinivasan, K and Dutta, P (2002) Rayleigh-Benard convection during solidification of an eutectic solution cooled from the top. In: Metallurgical and Materials Transactions B, 33 (4). pp. 605-612.

PDF Rayleigh–Benar.pdf - Published Version Restricted to Registered users only Download (487kB) | Request a copy

Abstract

The interaction between laminar Rayleigh-Benard convection and directional solidification is studied for the case of an eutectic solution kept in a rectangular cavity cooled from the top. Experiments and numerical simulations are carried out using an NH4Cl-H2O solution as the model fluid. The flow is visualized using a sheet of laser light scattered by neutrally buoyant, hollow-glass spheres seeded in the fluid. The numerical modeling is performed using a pressure-based finite-volume method according to the SIMPLER algorithm. The present configuration enables us to visualize flow vortices in the presence of a continuously evolving solid/liquid interface. Clear visualization of the Rayleigh-Benard convective cells and their interaction with the solidification front are obtained. It is observed that the convective cells are characterized by zones of up-flow and down-flow, resulting in the development of a nonplanar interface. Because of the continuous advancement of the solid/liquid interface, the effective liquid height of the cavity keeps decreasing. Once the height of the fluid layer falls below a critical value, the convective cells become weaker and eventually die out, leading to the growth of a planar solidification front. Results of flow visualization and temperature measurement are compared with those from the numerical simulation, and a good agreement is found.

Item Type:	Journal Article
Publication:	Metallurgical and Materials Transactions B
Publisher:	The Minerals, Metals & Materials Society
Additional Information:	Copyright of this article belongs to The Minerals, Metals & Materials Society.
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	28 Jul 2011 10:00
Last Modified:	28 Jul 2011 10:00
URI:	http://eprints.iisc.ac.in/id/eprint/39375

Actions (login required)

View Item