Transport of complex and active fluids in porous media

Abstract

Complex and active fluids find broad applications in flows through porous materials. Nontrivial rheology can couple to porous microstructure leading to surprising flow patterns and associated transport properties in geophysical, biological, and industrial systems. Viscoelastic instabilities are highly sensitive to pore geometry and can give rise to chaotic velocity fluctuations. A number of recent studies have begun to untangle how the pore-scale geometry influences the sample-scale flow topology and the resulting dispersive transport properties of these complex systems. Beyond classical rheological properties, active colloids and swimming cells exhibit a range of unique properties, including reduced effective viscosity, collective motion, and random walks, that present novel challenges to understanding their mechanics and transport in porous media flows. This review article aims to provide a brief overview of essential, fundamental concepts followed by an in-depth summary of recent developments in this rapidly evolving field. The chosen topics are motivated by applications, and new opportunities for discovery are highlighted.

Upstream wall vortices in viscoelastic flow past a cylinder

“…3D numerical simulations of viscoelastic flow past a cylinder, and a systematic experimental study that varies the channel blockage and aspect ratios, and the rheology of the test fluid will be instructive. Our results contribute to the rapidly growing understanding viscoelastic flow instabilities in microfluidic geometries, 15,24,57 and should be considered in the design of microfluidic devices and lab-on-a-chip systems that utilize viscoelastic fluids.…”

“…Such flows are prone to instability in a variety of different geometries, driven entirely by elastic effects. 4,[7][8][9][10][11][12][13][14][15] These elastic instabilities can affect widespread industrially and biologically relevant processes such viscoelastic flow in porous media, [16][17][18][19][20][21][22][23][24] hemodynamics, [25][26][27] and jet fragmentation. 28,29 A common morphological structure that appears due to elastic instability is the formation of a vortex, or vortices, upstream of a geometric feature in a channel.…”

Peeling of linearly elastic sheets using complex fluids at low Reynolds numbers

“…In recent times, there have been studies where ∼ O(10 −4 ) and lower [43] thereby allowing this simplification. We also note that for larger values of Wi, the onset of viscoelastic turbulence could affect the estimated predictions [44]. A more detailed stability analysis (linear or nonlinear) is needed to explain these effects [45].…”

Lagrangian stretching reveals stress topology in viscoelastic flows

“…where γ = 1 2 (∇u + ∇u ) and Ω = 1 2 (∇u − ∇u ) are the strain rate tensor and the vorticity tensor, respectively [4] However, the value of the flow-type parameter is Λ = 0, indicating purely shear deformation.…”

“…The stretching of long-chain polymers in flow imparts viscoelastic properties to fluids, which impact diverse industrial, geophysical, and biological applications [1][2][3][4]. Viscoelasticity leads to increased flow resistance in enhanced oil recovery, polymer processing, and microbial mining [5][6][7], and it enhances fluid and particulate transport in targeted drug delivery and reproduction [8][9][10].…”