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Density waves and $1/f$ density fluctuations in granular flow

Gongwen Peng·Hans J. Herrmann
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Abstract

We simulate the granular flow in a narrow pipe with a lattice-gas automaton model. We find that the density in the system is characterized by two features. One is that spontaneous density waves propagate through the system with well-defined shapes and velocities. The other is that density waves are so distributed to make the power spectra of density fluctuations as $1/f^α$ noise. Three important parameters make these features observable and they are energy dissipation, average density and the rougness of the pipe walls.

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Gongwen Peng, Hans J. Herrmann. 1994-08-24. Density waves and $1/f$ density fluctuations in granular flow. https://doi.org/10.1103/physreve.51.1745

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