Abstract
By means of particle dynamics simulations, we study the erosion of a granular system composed of wetmonodisperse spherical particles interacting via elastic, frictional and capillary forces, subjected to a flowof dry grains inclined above its angle of repose. We are interested in the effect of inclination angle andsurface tension on the time evolution of the erosion rate and diffusion of the cohesive particles into thedry grains. We consider two different scenarios, one in which the liquid surrounding a wet particle isevaporated after bond rupture, and another scenario in which the liquid is still available for creation ofnew cohesive bonds between initially wet particles. In the first case, the flowing dry particles graduallyerodes the underlying wet layer and a homogeneous mixture is achieved in finite time whereas in thesecond case, the eroded wet particles agglomerate at the free surface as shown in Fig. 1. We analyze theshort-time evolution of erosion in terms of the rate of erosion and the long-time behavior in terms ofmixing for different values of surface tension and inclination angle. We find that the data can be scaled bydimensionless parameters combining system parameters.