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arXiv · 2011.11283

Scalar signatures of chaotic mixing in porous media

Heyman J.·Lester D.·Le Borgne T
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Abstract

Steady laminar flows through porous media spontaneously generate Lagrangian chaos at pore scale, with qualitative implications for a range of transport, reactive and biological processes. The characterization and understanding of mixing dynamics in these opaque environments is an outstanding challenge. We address this issue by developing a novel technique based upon high-resolution imaging of the scalar signature produced by push-pull flows through porous media samples. Owing to the rapid decorrelation of particle trajectories in chaotic flows, the scalar image measured outside the porous material is representative of in-situ mixing dynamics. We present a theoretical framework for estimation of the Lyapunov exponent based on extension of Lagrangian stretching theories to correlated aggregation. This method provides a full characterization of chaotic mixing dynamics in a large class of porous materials.

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Heyman J., Lester D., Le Borgne T. 2020-11-23. Scalar signatures of chaotic mixing in porous media. https://doi.org/10.1103/physrevlett.126.034505

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