Long-surface-wave instability in dense granular flows. (English) Zbl 1156.76458

This paper is devoted to an experimental study of the long-surface-wave instability that can develop when a granular material flows down a rough inclined plane. By imposing a controlled perturbation at the entrance of the flow, the authors have been able to precisely measure the threshold and dispersion relation of the instability. Another interesting result in this paper is the relative success of the depth-average equations in predicting the stability properties of granular flows. Once a relevant friction law is taken into account, quantitative properties can be predicted. This work thus provides a good test for the relevance of the friction law deduced from steady uniform flows, in a case where inertial effects determine the dynamics of the flow.


76T25 Granular flows
74E20 Granularity
76-05 Experimental work for problems pertaining to fluid mechanics
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