Structural evolution during ice‐sphere sintering

Abstract

AbstractTwo‐dimensional ice‐sphere arrays were produced in a cold room and studied as a geometrically simplified model of dry snow aggregates. The structural evolution of the ice‐sphere arrays under either a quasi‐isothermal condition or a temperature gradient was examined temporally. Two observational techniques were combined for the structural characterization. Optical microscopy was used to perform periodic observations, whereas scanning electron microscopy was used to both acquire high‐resolution images and confirm the hexagonal crystal structure. Different thermal conditions led to the development of different morphologies of necks between two ice spheres by affecting the water vapour transfer in the pore spaces and the sublimation–condensation of water molecules. The microstructure of necks could also play a significant role in the structure development at later times by inducing or enhancing the local temperature gradient. This feature was discussed on the basis of steady‐state heat transfer modelling of a two‐sphere structure. Copyright © 2010 John Wiley & Sons, Ltd.