Interpretation of the Orientation of Ice Dendrites Growing from Supercooled Water
Abstract An interpretation is proposed of the phenomenon of splitting of ice dendrites growing from supercooled water and of their orientation at an angle α to the basal plane. Both phenomena are related to the instabilities which develop on the dendritic cap when the ratio V c /V a of the growth ve...
| Published in: | Journal of Glaciology |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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Cambridge University Press (CUP)
1970
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0022143000026836 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000026836 |
| Summary: | Abstract An interpretation is proposed of the phenomenon of splitting of ice dendrites growing from supercooled water and of their orientation at an angle α to the basal plane. Both phenomena are related to the instabilities which develop on the dendritic cap when the ratio V c /V a of the growth velocities in the direction of the c- and a -axes exceeds a certain limit. The different interface supercoolings, (δ T i ) a and (δ T i ) c at the tip and at the sides of the dendrite cap are considered. Although V c /V a increases with the bath supercooling Δ T it is found that V c ≪ V a for (δ T i ) c = (δ T i ) a through the whole range investigated (o < Δ T ≤ 18 deg). The increase of α with the concentration of solutes is also qualitatively explained. Considering the kinetic theory of the molecular growth mechanism, the results obtained for V c as a function of (δ T i ) c would indicate that most of the studied interval must correspond to the transitional regime of growth. |
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