title: Relevance of numerical simulations to booming sand.
abstract: We have performed a simulation study of three-dimensional cohesionless granular flows down an inclined chute. We find that the oscillations observed in [L. E. Silbert, Phys. Rev. Lett. 94, 098002 (2005)] near the angle of repose are harmonic vibrations of the lowest normal mode. Their frequencies depend on the contact stiffness as well as on the depth of the flow. Could these oscillations account for the phenomena of "booming sand"? We estimate an effective contact stiffness from the Hertz law, but this leads to frequencies that are several times higher than observed. However, the Hertz law also predicts interpenetrations of a few nanometers, indicating that the oscillations frequencies are governed by the surface stiffness, which can be much lower than the bulk one. This is in agreement with previous studies ascribing the ability to sing to the presence of a soft coating on the grain surface.
authors.affiliation: Institut de Physique de Rennes, Université de Rennes I, UMR CNRS 6251, F-35042 Rennes, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Richard
authors.forename: Sean
authors.initials: S
authors.lastname: McNamara
authors.forename: Merline
authors.initials: M
authors.lastname: Tankeo
mesh_terms: D000465:Algorithms; D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D012212:Rheology / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D003102:Colloids; D012822:Silicon Dioxide