J. Phys. I France
Volume 5, Numéro 9, September 1995
Page(s) 1119 - 1128
DOI: 10.1051/jp1:1995185
J. Phys. I France 5 (1995) 1119-1128

Spontaneous Formation of Vortex in a System of Self Motorised Particles

Y. Limon Duparcmeur1, H. Herrmann2 and J. P. Troadec1

1  Groupe Matière Condensée et Matériaux (U.R.A 804), Université de Rennes I, Campus de Beaulieu, 35042 Rennes Cedex, France
2  Physique et Mécanique des Milieux Hétérogènes (U.R.A 857), Ecole Supérieure de Physique et Chimie Industrielles de la Ville de Paris, 10 rue Vauquelin, 75231 Paris Cedex 05, France

(Received 29 March 1995, received in final form 9 May 1995, accepted 11 May 1995)

We study a system of disks with inelastic collisions. Energy is given to the system via a force of constant modulus, applied on each particle in the direction of its velocity. This system shows a dynamical phase transition from a disordered system towards a system organized into a vortex when the dissipation is increased. The state equation of the disordered system is obtained by using kinetic theory arguments. We also show that the transition is similar to the kinetic-cluster transition observed in the cooling of a gas of inelastic particles.

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