2006/11/06 by Giulio Costantini, Umberto Marini Bettolo Marconi, Andrea Puglisi · 3 citations
Engineering · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Granular flow and fluidized beds #Particle Dynamics in Fluid Flows #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.75.061124
published as Phys. Rev. E 75, 061124 (2007) · 4 pages, 4 figures, submitted for publication
arxiv created 2006/11/06 · openalex publication_date 2007/06/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We show by numerical simulations that a nonrotationally symmetric body, whose orientation is fixed and whose center of mass can slide along a rectilinear guide, under the effect of inelastic collisions with a surrounding gas of particles, displays directed motion. We present a theory which explains how the lack of time reversal induced by the inelasticity of collisions can be exploited to generate a steady average drift. In the limit of a heavy ratchet, we derive an effective Langevin equation whose parameters depend on the microscopic properties of the system and obtain a fairly good quantitative agreement between the theoretical predictions and simulations concerning effective friction, diffusivity, and average velocity.