We performed molecular dynamics simulations of granular beds driven by a model hydrodynamic shear flow to elucidate general grain-scale mechanisms that determine the onset and cessation of sediment transport. By varying the Shields number (the nondimensional shear stress at the top of the bed) and particle Reynolds number (the ratio of particle inertia to viscous damping), we explore how variat...

Articles you may be interested in Erosion threshold of a liquid immersed granular bed by an impinging plane liquid jet A comparison of the predictions of a simple kinetic theory with experimental and numerical results for a vibrated granular bed consisting of nearly elastic particles of two sizes Onset of erosion and avalanche for an inclined granular bed sheared by a continuous laminar flow We...

The critical fluid-shear stress for the onset of sediment transport, θc, varies with history applied shear. This effect has been primarily attributed to compaction; role shear jamming is less explored. We examine response a granular bed cycles varying magnitude and direction, determine isotropic anisotropic contributions. Creep bed-load transport result in direction-dependent strain hardening θ...

This review describes the role of bone cells and their surrounding matrix in maintaining bone strength through the process of bone remodeling. Subsequently, this work focusses on how bone formation is guided by mechanical forces and fluid shear stress in particular. It has been demonstrated that mechanical stimulation is an important regulator of bone metabolism. Shear stress generated by inter...

Arterial shear stress is a potent stimulus to vascular adaptation in humans. Typically, increases in retrograde shear have been found to acutely impair vascular function while increases in antegrade shear enhance function. We hypothesized that blood flow and shear stress through the brachial and carotid arteries would change in a similar manner in response to water immersion, an intervention wh...

The linear stability of an erodible sediment bed beneath a turbidity current is analysed, in order to identify potential mechanisms responsible for the formation of longitudinal gullies and channels. On the basis of the three-dimensional Navier–Stokes equations, the stability analysis accounts for the coupled interaction of the three-dimensional fluid and particle motion inside the current with...

The  ow patterns and stresses on the wall in a moving granular bed with eccentric discharge were investigated experimentally. The  ow pattern histories of granular solids in the moving bed were recorded using a digital camcorder. The image processing system included a frame grabber. A new pressure gauge for simultaneously measuring the normal and shear stresses of granular solids was used. Du...