Effective thermal conductivity of a wet porous medium – presence of hysteresis when modeling the spatial water distribution for the pendular regime

Édouard Canot (1) , Renaud Delannay (2) , Salwa Mansour (1) , Mohamad Muhieddine (3) , Ramiro March (4)

1 SAGE - Simulations and Algorithms on Grids for Environment
2 IPR - Institut de Physique de Rennes
3 LIU - Lebanese International University
4 CReAAH - Centre de Recherche en Archéologie, Archéosciences, Histoire

This paper deals with the heat transfer between two spherical grains separated by a small gap; dry air is located outside the grains and a liquid water meniscus is supposed to be present between them. This problem can be seen as a micro-scale cell of an assembly of solid grains, for which we are looking for the effective thermal conductivity. For a fixed contact angle and according to the volume of the liquid meniscus, two different shapes are possible for the meniscus, giving a "contacting" state (when the liquid makes a true bridge between the two spheres) and a "non-contacting" one (when the liquid is split in two different drops, separated by a thin air layer); the transition between these two states occurs at different times when increasing or decreasing the liquid volume, thus leading to a hysteresis behavior when computing the thermal flux across the domain.

Mots clés: Wet porous media; Evaporation; Effective thermal conductivity; Hysteresis; Granular Medium

Domaines: Thermique [physics.class-ph]; Modélisation et simulation; Génie des procédés

Édouard Canot, Renaud Delannay, Salwa Mansour, Mohamad Muhieddine, Ramiro March. Effective thermal conductivity of a wet porous medium – presence of hysteresis when modeling the spatial water distribution for the pendular regime. Seventh Int. Conf. on Thermal Engineering (ICTEA 2014), Hasnaoui, M. and Saghir, M. Z., May 2014, Marrakesh, Morocco. pp.4. ⟨hal-01095522⟩