Yield stress fluid behavior of foam in porous media
Abstract
Flow of foams is studied in a model porous medium, in a large range of capillary numbers Ca and relative gas flow rates fg. From pressure measurements, we find that the effective viscosity is a decreasing power-law function of Ca, with the exponent ranging from -1 to -0.75 . Direct observation reveals that the flow is heterogeneous. The fraction of preferential paths increases with both fg and Ca. In a straight channel of varying cross section, a bubble train behaves as a shear-thinning yield stress fluid. This feature accounts quantitatively for the effective viscosity in the micromodel.
- Publication:
-
Physical Review Fluids
- Pub Date:
- September 2020
- DOI:
- 10.1103/PhysRevFluids.5.094004
- arXiv:
- arXiv:1906.04103
- Bibcode:
- 2020PhRvF...5i4004M
- Keywords:
-
- Physics - Fluid Dynamics
- E-Print:
- Phys. Rev. Fluids 5, 094004 (2020)