The growth of ice crystals

Abstract

An experimental investigation is reported of the A-axis and C-axis growth rates in water and brine in a channel immersed in a thermostatically controlled bath. Single crystals were nucleated from a capillary nucleating head, which could be rotated for measurement of C-axis growth rates. A-axis results are presented for subcoolings from 0.1 K to 1.0 K, for growth in water at velocities between 5 cm/sec and 23 cm/sec and in brine up to 6% salt concentration at 5 cm/sec and 12.5 cm/sec. While growth rates in water agree well with those of previous workers, those in brine are lower than any previously reported. At low subcoolings the growth rate varies linearly with Δ T, but at higher subcoolings the relationship is ν = AΔ T n, where n increases from about 1.45 for water to about 2.25 for 5% salt concentration. A new theory, based on conduction in the ice crystal, is outlined for the growth rate at high Δ T, and this yields more reasonable values of the constant A than previous theories. The experimental results presented for C-axis growth indicate considerably lower growth rates than any previously published.