The Thermodynamics of a Single Bead in a Vibrating Container


P. Evesque: Lab MSSM, UMR 8579 CNRS, Ecole Centrale Paris, 92295 Châtenay-Malabry, France,


Abstract: Statistics of the 1d dynamics of a single particle in a box of length L is studied under different conditions of periodic excitation: vibrated container, or 1 wall moving periodically or two walls vibrating in opposite phases. Theoretical predictions for the mean typical speed <v> are derived using some Random Phase Approximation (RPA) for small b/L ratio, as functions of the amplitude b and frequency f =n =2p/w of vibration and of the collision restitution coefficient r=vout/vin. They are compared to numerical simulations. It is concluded that RPA is valid for b/L>0.005, that long time memory, i.e. non ergodicity, and/or resonance develop at large r (r>0.95) and/or at large b/L, that <v> scales always as f, and scales as b except for large b/L values, i.e. b/L>0.02, and that the relative velocity <V>=[<v>/(bw)] » 1 when r<0.4-0.5 . Relative standard deviation DV/V is found to be approximately constant, i.e. DV/V » 0.3 except when resonance; in this case, memory effect and non ergodicity effects are observed and become too important . 

Pacs # : 5.40 ; 45.70 ; 64 ; 83.70.Fn

poudres & grains 12 (2) 17-42 (mars 2001)