One-dimensional Brownian motion in hard rods: The adiabatic piston problem
1 Department of Physics, University of Zanjan - P.O. Box 313, Zanjan, Iran
2 Computational Physical Sciences Research Laboratory, School of Nano- Science, Institute for Research in Fundamental Sciences (IPM) - P.O. Box 19395-5531, Tehran, Iran
Received: 3 August 2013
Accepted: 28 October 2013
We have investigated the motion characteristics of a movable piston immersed in a one-dimensional gas of hard rods by event-oriented molecular dynamics in the absence of thermal noise. Periodic and reflecting boundary conditions are explored. It is shown that the piston undergoes systematic oscillations with decaying amplitudes in short times before it comes to global thermodynamic equilibrium. Moreover, the diffusion of the piston is explored and analytical expressions for its equilibrium mean-squared displacement (MSD) are obtained. It is shown that the MSD of the piston does not differ much from the normal rods despite its mass and length are significantly larger.
PACS: 05.40.-a – Fluctuation phenomena, random processes, noise, and Brownian motion / 05.70.Ce – Thermodynamic functions and equations of state / 64.60.Cn – Order-disorder transformations
© EPLA, 2013