- Open Access
New Form of Mixing in Turbulent Sedimentation
Phys. Rev. Lett. 136, 104003 – Published 11 March, 2026
DOI: https://doi.org/10.1103/tc5z-rxcf
Abstract
We study the sedimentation of finite-size inertial particles in a Rayleigh-Taylor-like setup using state-of-the-art direct numerical simulations. The falling particles are observed to produce two distinct regions: a leading mixing layer with a linear concentration profile followed by a bulk region of uniform density. Unlike classical RT turbulence, the mixing layer extension accelerates with an anomalous, noninteger exponent, while the bulk region moves at a constant velocity. A one-dimensional model based on a local hindered settling law accurately captures the observed dynamics and its dependence on the particle-to-fluid density ratio. The present Letter identifies a new regime of convective mixing which develops at the front of particle suspensions in sedimentation processes.
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