Vertically shaken column of spheres. Onset of fluidization
نویسندگان
چکیده
The onset of surface fluidization of granular material in a vertically vibrated container, z = A cos (ωt), is studied experimentally. Recently, for a column of spheres it has been theoretically found [1] that the particles lose contact if a certain condition for the acceleration amplitude z̈ ≡ Aω/g = f(ω) holds. This result is in disagreement with other findings where the criterion z̈ = z̈crit = const. was found to be the criterion of fluidization. We show that for a column of spheres a critical acceleration is not a proper criterion for fluidization and compare the results with theory.
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