Numerical prediction of bed-load and surface deformation on a granular bed sheared by a turbulent boundary-layer

The entrainment of solid particles by a fluid flow is frequently found in nature and in industry. A better knowledge of this is of importance to understand the physical nature of the phenomenon and to improve industrial processes. Bed-load occurs if the shear stresses exerted by the fluid on the granular bed are bounded to some limits: a mobile granular layer takes place over the fixed part of the bed. When the fluid is a liquid, the thickness of this mobile layer is a few grain-diameters. Under these conditions, an initially flat granular bed may be unstable, giving rise to ripples and dunes....