A numerical model of convective effects in diffusion dominated directional solidification of a metal analogue (NH4Cl-H2O) at one gravity and microgravity

Author

Samuel A. Lowry

Date of Award

5-1991

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major

Engineering Science

Major Professor

T. Dwayne McCay

Abstract

A numerical model is developed to simulate the directional solidification of a dendritic metal analogue material, ammonium chloride and water, in support of a planned series of microgravity experiments. The model is first validated by comparison with ground-based data. Undercooling (non-equilibrium) effects are shown to be significant. The one-gravity computations correlate well with the ground-based data for the initial diffusion limited growth and the transition to dominant convective flows at a critical solutal and thermal Rayleigh number. The model is then used to predict the directional dendritic solidification for a sample low gravity run and the results are compared with one-gravity data.

Recommended Citation

Lowry, Samuel A., "A numerical model of convective effects in diffusion dominated directional solidification of a metal analogue (NH4Cl-H2O) at one gravity and microgravity. " PhD diss., University of Tennessee, 1991.
https://trace.tennessee.edu/utk_graddiss/11169