Pore network study of bubble growth by vaporisation in a porous medium heated laterally

Clément Louriou (1) , Marc Prat (1)

1 IMFT - Institut de mécanique des fluides de Toulouse

We present experimental and numerical investigations of vapour phase growth in a two-dimensional model porous medium heated laterally. Visualisation experiments reveal the existence of a heat pipe effect within the porous medium when a sufficiently high temperature gradient develops along the porous medium. The bubble growth is characterised by a pattern transition between an invasion percolation (IP) pattern in a first phase of the growth and an invasion percolation in a destabilising gradient (IPDG) at later times. It is shown that this transition corresponds at the pore scale to a transition between an invasion scenario where only one pore is invaded at each step of the invasion and a multiple pore invasion scenario. The IPDG pattern is characterised by the development of a thin vapour finger, which can explain premature vapour breakthroughs. This type of vapour finger cannot be simulated accurately using traditional models based on the continuum approach to porous media.

Mots clés: Porous media; Vaporisation; Pore network model; Heat transfer

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Clément Louriou, Marc Prat. Pore network study of bubble growth by vaporisation in a porous medium heated laterally. International Journal of Thermal Sciences, 2012, vol. 52, pp. 8-21. ⟨10.1016/j.ijthermalsci.2011.09.008⟩. ⟨hal-00925602⟩