Models of granular ratchets
Soft Condensed Matter
2015-05-13 v1 Statistical Mechanics
Abstract
We study a general model of granular Brownian ratchet consisting of an asymmetric object moving on a line and surrounded by a two-dimensional granular gas, which in turn is coupled to an external random driving force. We discuss the two resulting Boltzmann equations describing the gas and the object in the dilute limit and obtain a closed system for the first few moments of the system velocity distributions. Predictions for the net ratchet drift, the variance of its velocity fluctuations and the transition rates in the Markovian limit, are compared to numerical simulations and a fair agreement is observed.
Cite
@article{arxiv.0905.4168,
title = {Models of granular ratchets},
author = {G. Costantini and A. Puglisi and U. Marini Bettolo Marconi},
journal= {arXiv preprint arXiv:0905.4168},
year = {2015}
}
Comments
15 pages, 4 figures, to be published on Journal of Statistical Mechanics: Theory and Experiments