The collapse of a granular column onto an erodible bed: dynamics and morphology scaling

Abstract

The collapse of a granular column onto an erodible bed is studied experimentally and numerically, and underlying scaling laws on deposition morphology and erosion geometry are mainly considered. The differences in material properties between the column and the erodible bed give rise to the change in flow behaviors, in which the particle density ratio between the column and the erodible bed plays a crucial role. The flow duration apparently increases with initial aspect ratio $$a$$ , but its normalized value tends to a constant at large $$a$$ regardless of particle density ratio. Furthermore, several univariable scaling laws are put forward to quantitatively characterize final deposition morphology and erosion geometry. By rescaling these univariable functions, the generalized scaling laws containing two relevant variables are further proposed, which have been verified to be applicable for a wider range of situations where the degree of erosion dominates the propagation of collapsing flow.