Europhys. Lett.
Volume 74, Number 1, April 2006
Page(s) 1 - 7
Section General
Published online 22 February 2006
Europhys. Lett., 74 (1), pp. 1-7 (2006)
DOI: 10.1209/epl/i2005-10502-7

Power law in the angular velocity distribution of a granular needle

J. Piasecki1 and P. Viot2

1  Institute of Theoretical Physics, University of Warsaw Hoza 69, 00 681 Warsaw, Poland
2  Laboratoire de Physique Théorique de la Matière Condensée Université Pierre et Marie Curie - 4 place Jussieu 75252 Paris Cedex 05, France

received 27 December 2005; accepted in final form 6 February 2006
published online 22 February 2006

We show how inelastic collisions induce a power law with exponent -3 in the decay of the angular velocity distribution of anisotropic particles with sufficiently small moment of inertia. We investigate this question within the Boltzmann kinetic theory for an elongated granular particle immersed in a bath. The power law persists so long as the collisions are inelastic for a large range of angular velocities provided the mass ratio of the anisotropic particle and the bath particles remains small. Suggestions for observing this peculiar feature are made.

05.20.Dd - Kinetic theory.
45.70.-n - Granular systems.

© EDP Sciences 2006