Numerical simulations of thermal regelation phenomena around a spherical particle

A solid object surrounded by a frozen liquid, everywhere below the melting temperature, can still have a thin liquid layer at the interface because of the reduced free-energy content of this configuration. Thermal regelation occurs whenever a temperature gradient is present with the solid object moving towards warmer temperature regions.

This is the case of water and soil grains in permafrost and it is the reason for frost heave phenomena.

In the present study we report results from numerical simulations of thermal regelation phenomena around a solid spherical particle.

We rely on an extensively validated phase-field Navier-Stokes solver (AFiD-Murphy) coupled with an immersed-boundary method to solve the full fluid/structure interaction dynamics.

Results show that the particle motion agrees with the theory when all phases have identical thermal properties (thermal conductivity and specific heat capacity); in contrast, when each phase retains its own thermal features, the system dynamics is altered showing large deviations from the theory.