Viscoelastic flow simulations in disordered porous media

Abstract

We investigate creeping flow of a viscoelastic fluid through a three dimensional random porous medium using computational fluid dynamics. The simulations are performed using a finite volume methodology with a staggered grid. The no slip boundary condition on the fluid-solid interface is implemented using a second order finite volume immersed boundary (FVMIBM) methodology [1]. The viscoelastic fluid is modelled using a FENE-P type constitutive relation. The simulations reveal a transition of flow structure from a laminar Newtonian regime to a nonstationary non-Newtonian regime with increasing viscoelasticity. We find that the flow profiles are mainly governed by the porous microstructure. By choosing a proper length scale a universal curve for the flow transition can be obtained. A study of the flow topology shows how in such disordered porous media shear, extensional and rotational contributions to the flow evolve with increased viscoelasticity.