### Project Title:

Computational Methodologies for Convection- Diffusion Phase Change Problems

15.03-2620
Computational Methodologies for Convection-
Diffusion Phase Change Problems
CHAM of North America, Inc.
1525-A Sparkman Drive
Huntsville, AL 35816
C. Prakash (205-830-2620)
LeRC -- NAS3-25331

### Abstract:

The objective of this project was to develop numerical methodologies for analyzing
solid-liquid phase change problems involving multi-component materials such as binary
mixtures and alloys. The potential NASA interest for this work stems from materials
science applications in space, e.g. crystal growth.
The aim of Phase I was to define a framework for development of a general purpose
computer program by examining both single- and two-phase models. The single-phase
model equations are relatively easy to solve but require a prescription of the solid
phase-velocity and other assumptions for computing the local mass fractions of the
phases. The two-phase model does not have these shortcomings but needs data on interfacial
exchange coefficients which require further research. The problem of freezing in
a square 2was studied to illustrate the use of the single- and two-phase models.
The conclusion drawn from this work is that a general purpose code for binary solid-liquid
phase change problems must include both single-and two-phase options.

### Potential Commercial Application:

Potential Commercial Application: Solutions to problems of convection-diffusion,
multi-component, phase change would reduce the need for experiments and would supplement
space materials processing research.