Competitive dynamics of two erosion patterns around a cylinder

F. Lachaussée (1) , Yann Bertho (1) , Cyprien Morize (1) , A. Sauret (2) , P. Gondret (1)

1 FAST - Fluides, automatique, systèmes thermiques
2 SVI - Surface du Verre et Interfaces

We investigate experimentally the local erosion of a granular bed near a fixed vertical cylinder that emerges from the bed. The onset of erosion arising at the base of the cylinder and usually ascribed to the wrapping horseshoe vortex is determined and rationalized by a flow contraction effect. We report another erosion pattern visible downstream of the cylinder that consists of two side-by-side elongated holes. This pattern is observed for flow regimes close to the horseshoe scour onset, whose growth usually inhibits its spatiotemporal development.

Mots clés: Erosion; Granular Matter; Fluid Mechanics; Erosion

Domaines: Mécanique des fluides [physics.class-ph]

F. Lachaussée, Yann Bertho, Cyprien Morize, A. Sauret, P. Gondret. Competitive dynamics of two erosion patterns around a cylinder. Physical Review Fluids, 2018, 3 (1), pp.012302. ⟨10.1103/physrevfluids.3.012302⟩. ⟨hal-04439084⟩