Soft disks in a narrow channel

Jammed disks of two sizes in a narrow channel

A granular-matter model is exactly solved, where disks of two sizes and weights in alternating sequence are confined to a narrow channel. The axis of the channel is horizontal and its plane vertical. Disk sizes and channel width are such that under jamming no disks remain loose and all disks touch one wall. Jammed microstates are characterized via statistically interacting particles constructed out of two-disk tiles. Jammed macrostates depend on measures of expansion work, gravitational potential energy, and intensity of random agitations before jamming. The dependence of configurational entro…

Structural properties of hard disks in a narrow tube

Positional ordering of a two-dimensional fluid of hard disks is examined in such narrow tubes where only the nearest-neighbor interactions take place. Using the exact transfer-matrix method the transverse and longitudinal pressure components and the correlation function are determined numerically. Fluid-solid phase transition does not occur even in the widest tube, where the method just loses its exactness, but the appearance of the dramatic change in the equation of state and the longitudinal correlation function shows that the system undergoes a structural change from a fluid to a solid-like…

受限于狭窄通道的硬盘

Hard disks confined within a narrow channel

研究硬盘在狭窄通道中的行为，利用非均匀积分方程理论揭示准一维限制下的结构转变特性。

Heat conduction and diffusion of hard disks in a narrow channel

Using molecular dynamics we study heat conduction and diffusion of hard disks in one dimensional narrow channels. When collisions preserve momentum the heat conduction $κ$ diverges with the number of disks $N$ as $κ\sim N^α$ $(α\approx 1/3)$. Such a behaviour 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 behaviour and on an intermediate time scale (that diverges in the thermodynamic limit) normal diffusion takes place even in the 'pen-case' model. W…

Hard Disks in Narrow Channels

The thermodynamic and dynamical behavior of a gas of hard disks in a narrow channel is studied theoretically and numerically. Using a virial expansion we find that the pressure and collision frequency curves exhibit a singularity at a channel width corresponding to twice the disk diameter. As expected, the maximum Lyapunov exponent is also found to display a similar behavior. At high density these curves are dominated by solid-like configurations which are different from the bulk ones, due to the channel boundary conditions.

Disks in a narrow channel jammed by gravity and centrifuge: profiles of pressure, mass density and entropy density

This work investigates jammed granular matter under conditions that produce heterogeneous mass distributions on a mesoscopic scale. We consider a system of identical disks that are confined to a narrow channel, open at one end and closed off at the other end. The disks are jammed by the local pressure in a gravitational field or centrifuge. All surfaces are hard and frictionless. We calculate the profiles of pressure, mass density, and entropy density on a mesoscopic length scale under the assumption that the jammed states are produced by random agitations of uniform intensity along the channe…