InterPore2025

Phase-field modeling of snow microstructure evolution

19 May 2025, 11:55

15m

Oral Presentation (MS06-B) Interfacial phenomena across scales MS06-B

Speaker

Xiaojing Fu (California Institute of Technology)

Description

The microstructure of snow determines its fundamental properties such as the mechanical strength, reflectivity, or the thermo-hydraulic properties. Snow undergoes continuous microstructural changes due to local gradients in temperature, humidity or curvature, in a process known as snow metamorphism. Dry snow metamorphism occurs at temperature below the melting point where the snow is assumed to be absent with liquid water; wet snow metamorphism occurs when temperature is close to the melting point and involves phase transitions amongst liquid water, water vapor, and solid ice.
In this work, we describe our recent efforts in developing a pore-scale phase-field model that simultaneously captures the three phase-change phenomena relevant to snow metamorphism: sublimation (deposition), evaporation (condensation), and melting (solidification). The phase-field formulation allows one to track the temperature evolution amongst the three phases and the water vapor concentration in the air. Our three-phase model recovers the corresponding two-phase transition model when one phase is not present in the system. We perform 3D simulations of the two-phase model to study sintering of ice particles (i.e., dry metamorphism) and find that the model can reproduce the neck growth rate measured in controlled laboratory experiments at two different temperatures. We then perform 2D simulations of the three-phase model to study the impact of humidity and temperature on the dynamics of wet snow metamorphism at the pore scale. We explore the role of liquid melt content in controlling the dynamics of snow metamorphism in contrast to the dry regime, before percolation onsets. The model can be readily extended to incorporate two-phase flow and may be the basis for investigating other problems involving water phase transitions in a vapor-solid-liquid system such as airplane icing or thermal spray coating.