Author(s)

C S Stampa, A O Nieckele & S L Braga

Abstract

The aim of this paper is to investigate the effect of super-heating for solid-liquid phase change problems, involving solidification of binary substances. Numerical calculations have been performed for the NH4CL-H20system, at different superheating conditions, to be possible to predict the general behavior of a hypoeutectic mixture during freezing. Local volume-averaged conservation equations were used to solve a two-dimensional problem in a vertical annular enclosure with buoyancy driven flow in the melt. The results were analyzed regarding the transient behavior of the flow patterns and temperature distributions in the domain, through streamlines and isotherms, respectively. Further, one has investigated the transient behavior of the cold wall averaged heat flux and the energy removed, during this process. All the results were obtained for a range from 0°C to 40°C of super-heating.

Keywords