Thermal Convection in a 3D Fractured Porous Medium

Cécile Mezon (1, 2) , Valeri V. Mourzenko (3, 4, 5) , Jean-François Thovert (4, 3, 5) , P.M Adler (2)

1 LGSR - Laboratoire GéoSciences Réunion
2 METIS - Milieux Environnementaux, Transferts et Interactions dans les hydrosystèmes et les Sols
3 Département FTC - Département Fluides, Thermique et Combustion [Institut Pprime]
4 CH - Combustion hétérogène et milieu poreux [Institut Pprime]
5 PPrime [Poitiers] - Institut Pprime [UPR 3346]

Thermal convection is numerically computed in 3D fluid saturated fractured porous media. Fractures are inserted as 2D convex polygons, which are randomly located. The fluid is assumed to satisfy 2D and 3D Darcy's law in the fractures and in the porous medium, respectively; exchanges take place between these two structures. After some necessary comparisons with results relative to homogeneous porous media, systematic calculations are performed for Rayleigh numbers up to 150 for various values of the fracture density and the fracture aperture. The increase in output flux with fracture density is found to be linear over the range of fracture density tested. Moreover, the importance of the percolating character of the fracture network is emphasized. Finally, the effective medium approach is found to be precise only for small or large fracture densities.

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

Cécile Mezon, Valeri V. Mourzenko, Jean-François Thovert, P.M Adler. Thermal Convection in a 3D Fractured Porous Medium. 51st U.S. Rock Mechanics/Geomechanics Symposium, Jun 2017, San Francisco, California, United States. ⟨hal-03110129⟩