InterPore2023

Numerical investigation of chaotic advection in porous media at the Pore and Darcy scales

24 May 2023, 16:10

1h 30m

Poster Presentation (MS08) Mixing, dispersion and reaction processes across scales in heterogeneous and fractured media Poster

Speaker

Stefano Ascione

Description

Solute transport in porous media plays a significant role in industrial and natural processes, since porous materials are ubiquitous on Earth. Modelling transport is important for various applications, including soil moisture dynamics, groundwater pollution, and oil recovery. Previous research suggested that chaotic mixing [1], e.g. the exponential elongation of fluid elements by advection, strongly depends on lattice geometries, flow direction [2] and packing density [3]. However, a universal understanding of chaotic advection at Pore and Darcy scales is still missing. Here, we present a numerical study of 3D Pore and Darcy scale flows through various representative elementary volumes. In this instance, we consider the impact of impermeable inclusions on the mixing dynamics of homogeneous Darcy flow. We computed Stokes and Darcy velocities for constant pressure gradient in mono-dispersed bead packs with body-centered cubic (BCC), face-centered cubic (FCC), and random lattices. By computing periodic trajectories, we then estimate the magnitude of the largest Lyapunov exponent in all these flows fields, and compare them with a new predictive model. Our results provide original perspectives on the control of chaotic mixing by the porous structure.

References

[1] D. Lester, G. Metcalfe, and M. Trefry, “Is chaotic advection inherent to porous media flow?,” Physical Review Letters, vol. 111, no. 17, pp. 174101–1 – 174101–5, 2013.
[2] R. Turuban, D. R. Lester, J. Heyman, T. L. Borgne, and Y. Meheust, “Chaotic mixing in crystalline granular media,” Journal of Fluid Mechanics, vol. 871, p. 562–594, 2019.
[3] J. Heyman, D. R. Lester, R. Turuban, Y. Meheust, and T. L. Borgne, “Stretching and folding sustain microscale chemical gradients in porous media,” Proceedings of the National Academy of Sciences, vol. 117, no. 24, pp. 13359–13365, 2020.