New boundary conditions for granular fluids

Mark D. Shattuck

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arXiv · cond-mat/0703575

New boundary conditions for granular fluids

Mark D. Shattuck

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Abstract

We present experimental evidence, which contradicts the the standard boundary conditions used in continuum theories of non-cohesive granular flows for the velocity normal to a boundary u.n=0, where n points into the fluid. We propose and experimentally verify a new boundary condition for u.n, based on the observation that the boundary cannot exert a tension force Fb on the fluid. The new boundary condition is u.n=0 if Fb.n>=0 else n.P.n=0, where P is the pressure tensor. This is the analog of cavitation in ordinary fluids, but due the lack of attractive forces and dissipation it occurs frequently in granular flows.

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Mark D. Shattuck. 2007-03-22. New boundary conditions for granular fluids. https://arxiv.org/abs/cond-mat/0703575

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