Sediment erosion in zero-mean-shear turbulence

Abstract : A stirring grid, in a square tank, located more than 2 mesh sizes away from a sediment layer, is used to study particle erosion by a zero-mean-shear turbulence. The particle concentration has been monitored using an OBS technique and fluid velocity mostly through PIV. Particle lift-off and concentration in the tank are shown to rise sharply as the grid frequency is increased. Converged velocity profiles indicate that the bulk isotropy of the turbulent velocity in the tank, well predicted by a slightly modified Matsunaga et al. (1999) model, gets broken close to the bed. While mean shear rates are shown to be small at the bed surface, some high shear level events induced by vortex impacts are assumed to be responsible for the particle erosion.
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Contributor : Hervé Michallet <>
Submitted on : Wednesday, August 30, 2017 - 3:53:56 PM
Last modification on : Thursday, January 3, 2019 - 4:30:09 PM

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  • HAL Id : hal-01579186, version 1

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Marie Rastello, Hervé Michallet, Jean-Louis Marié. Sediment erosion in zero-mean-shear turbulence. Coastal Dynamics 2017, Troels Aagaard, Rolf Deigaard, David Fuhrman, Jun 2017, Helsingør, Denmark. pp.597-607. ⟨hal-01579186⟩

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