Europhys. Lett.
Volume 70, Number 4, May 2005
Page(s) 478 - 484
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 15 April 2005
Europhys. Lett., 70 (4), pp. 478-484 (2005)
DOI: 10.1209/epl/i2004-10507-8

Towards a continuum theory of clustering in a freely cooling inelastic gas

B. Meerson1 and A. Puglisi2

1  Racah Institute of Physics, Hebrew University of Jerusalem - Jerusalem 91904, Israel
2  Laboratoire de Physique Théorique (UMR 8627 du CNRS), Bâtiment 210 Université de Paris-Sud - 91405 Orsay Cedex, France

received 8 December 2004; accepted in final form 24 March 2005
published online 15 April 2005

We performed molecular-dynamics simulations to investigate the clustering instability of a freely cooling dilute gas of inelastically colliding disks in a quasi-one-dimensional setting. We observe that, as the gas cools, the shear stress becomes negligibly small, and the gas flows by inertia only. Finite-time singularities, intrinsic in such a flow, are arrested only when close-packed clusters are formed. We observe that the late-time dynamics of this system are describable by the Burgers equation with vanishing viscosity, and predict the long-time coarsening behavior.

45.70.-n - Granular systems.
45.70.Qj - Pattern formation.

© EDP Sciences 2005