Heat conduction and diffusion of hard disks in a narrow channel
A. Lipowski1 , D. Lipowska1
1 Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań, Poland
2 Institute of Linguistics, Adam Mickiewicz University, 60-371 Poznań, Poland
Physical Review E, 75, 052201 (2007)
Using molecular dynamics we study heat conduction and diffusion of hard disks in one-dimensional narrow channels. When collisions preserve momentum the heat conduction kappa diverges with the number of disks N as kappa approximately N alpha (alpha approximately 1/3) . Such a behavior is seen both when the ordering of disks is fixed ("pen-case" model), and when they can exchange their positions. Momentum conservation results also in sound-wave effects that enhance diffusive behavior and on an intermediate time scale (that diverges in the thermodynamic limit) normal diffusion takes place even in the "pen-case" model. When collisions do not preserve momentum, kappa remains finite and sound-wave effects are absent.