Non-Newtonian fluid flow in geological rough fractures: lubrication approximation versus direct 3D simulations

Alessandro Lenci (1) , Clément Roques (2) , Yves Méheust (2) , Vittorio Di Federico (1)

1 UNIBO - Alma Mater Studiorum Università di Bologna = University of Bologna
2 GR - Géosciences Rennes

We simulate non-Newtonian flow in rough fractures. Random aperture fields with isotropic spatial correlations are generated using an FFT-based algorithm. We first solve the flow with a finite-difference code based on the lubrication approximation for power law and Carreau rheologies (2D approach). We then solve a modified Navier-Stokes equation incorporating both rheologies, in the 3D fracture space (3D approach). The 2D approach's efficiency to predict the flow distribution in the fracture plane depends on the fracture closure and correlation length.

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

Alessandro Lenci, Clément Roques, Yves Méheust, Vittorio Di Federico. Non-Newtonian fluid flow in geological rough fractures: lubrication approximation versus direct 3D simulations. XXIII Computational Methods in Water Resources, Dec 2020, Stanford, United States. ⟨insu-03103462⟩