Sand Ripples and Dunes
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François Charru [1] ; Bruno Andreotti [2]
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[1] Université de Toulouse
Université de Toulouse
Arrondissement de Toulouse, Francia
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[2] Université Denis Diderot
Université Denis Diderot
París, Francia
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- Localización: Annual review of fluid mechanics, ISSN 0066-4189, Nº. 45, 2013, págs. 469-493
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
An erodible bed sheared by a fluid flow, gas or liquid, is generally unstable, and bed forms grow. This review discusses the following issues, in light of the recent literature: What are the relevant dynamical mechanisms controlling the emergence of bed forms? Do they form by linear instability or nonlinear processes such as pattern coarsening? What determines their timescales and length scales, so different in air and water? What are the similarities and differences between aeolian and subaqueous patterns? What is the influence of the mode of transport: bed load, saltation, or suspension? Can bed forms emerge under any hydrodynamical regime, laminar and turbulent? Guided by these questions, we propose a unified description of bed-form growth and saturation, emphasizing the hydrodynamical regime in the inner layer and the relaxation phenomena associated with particle transport.
