Stefano ASCIONE, new PhD student

Chaotic mixing in porous materials
Stefano ASCIONE, new PhD student

Stefano's PhD research, entitled ”Chaotic mixing in porous materials,” will be part of the REDI program run in association with the Royal Melbourne Institute of Technology (RMIT). 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. This study will be done exploring the emerging of chaos in discrete and continuous porous network
and comparing the Lyapunov exponents for different type of flows within several geometries. Interesting examples of geometries are regular lattices, random packing with polydisperse beads and discrete fracture network. This numerical study will be done analyzing flows through various representative elementary volumes, highlighting
their impact on chaotic mixing.

[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.