2007/03/03 by Harold Auradou, Auradou, Harold, Alejandro Boschan +9
Engineering · Environmental Science · #FOS: Physical sciences #Fluid Dynamics (physics.flu-dyn) #Groundwater flow and contamination studies #Hydraulic Fracturing and Reservoir Analysis #Soil and Unsaturated Flow
paper · pdf · doi:10.48550/arxiv.physics/0703029
openalex publication_date 2007/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Flow and transport are studied in transparent model fractures with rough complementary self-affine walls with a relative shear displacement u. The aperture field is shown to display long range correlations perpendicular to u: for flow in that direction, the width and geometry of the front of a dyed shear-thinning polymer solution displacing a transparent one have been studied as a function of the fluid rheology and flow rate. The front width increases linearly with distance indicating a convection of the fluids with a low transverse mixing between the flow paths. The width also increases with the flow-rate as the fluid rheology shifts from Newtonian at low shear rates γ towards a shear thinning behaviour at higher γ values. The width also increases with the polymer concentration at high flow-rates. These results demonstrate the enhancement of the flow velocity contrasts between different flow channels for shear thinning fluids. The relative widths at low and high γ values for different polymer concentrations are well predicted by an analytical model considering the fracture as a set of parallel ducts of constant hydraulic apertures. The overall geometry of the experimental front geometry is also predicted by the theoretical model from the aperture map.