Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

MULTIDIRECTIONAL SOLIDIFICATION OF AN AQUEOUS AMMONIUM CHLORIDE SOLUTION

Get access (open in a dialog) DOI: 10.1615/IHTC10.1640
pages 79-84

Abstrakt

In this study, conditions associated with concurrent solidification of aqueous ammonium chloride (NH4CL-H20) from both the side and bottom walls of a rectangular mold are considered experimentally and theoretically. Flow visualization reveals simultaneous evolution of two forms of double-diffusive convection (cellular and finger) in the melt, as well as evidence of significant dendrite fragmentation and transport of fragments in the melt. Temperature and composition measurements reveal the existence of solutal stratification throughout the solidification process and development of a thermal inversion during intermediate stages of solidification. Comparisons of measured temperatures and compositions with predictions based on a continuum model reveal the need for model improvements, particularly with respect to the inclusion of particle transport and nonequilibrium effects.