Abstract
We study the overdamped sedimentation of non-Brownian objects of irregular shape using fluctuating hydrodynamics. The anisotropic response of the objects to flow, caused by their tendency to align with gravity, directly suppresses concentration and velocity fluctuations. This allows the suspension to avoid the anomalous fluctuations predicted for suspensions of symmetric spheroids. The suppression of concentration fluctuations leads to a correlated, hyperuniform structure. For certain object shapes, the anisotropic response may act in the opposite direction, destabilizing uniform sedimentation.
- Received 26 December 2016
DOI:https://doi.org/10.1103/PhysRevLett.118.158005
© 2017 American Physical Society
Physics Subject Headings (PhySH)
Focus
Why Sediments Are So Uniform
Published 14 April 2017
A new theory suggests that sedimenting particles of irregular shape will drift horizontally as they fall, a result that may resolve a long-standing puzzle.
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