Avalanches at rough surfaces

Avalanches at rough surfaces.

We describe the surface properties of a simple lattice model of a sandpile that includes evolving structural disorder. We present a dynamical scaling hypothesis for generic sandpile automata and, additionally, explore the kinetic roughening of the sandpile surface, indicating its relationship with the sandpile evolution. Finally, we comment on the surprisingly good agreement found between this ...

Electrocapillary coupling at rough surfaces.

We investigate the impact of the surface roughness on the experimental value of the electrocapillary coupling coefficient, ς. This quantity relates the response of electrode potential, E, to tangential elastic strain, e, and also measures the variation of the surface stress, f, with the superficial charge density, q. We combine experiments measuring the apparent coupling coefficient ςeff for go...

Modeling Rough Surfaces

Dynamical equilibrium of avalanches on a rough plane

We present experimental results on avalanches which are triggered in a metastable static layer on a rough inclined plane. We observe that despite the continuous increase in mass of a perturbation while it runs down, the flow reaches a dynamical equilibrium where the fronts evolve at constant speed and the mass is spread. The head front is found to be a shock wave with a crest, and its transient...

Scattering on Multiscale rough surfaces

We present a method to recover a fractal dimension of a multi-scale rough surface, the so-called correlation dimension, from the knowledge of the far-field scattered intensity. The results are validated by numerical experiments on Weierstrass-like surfaces.