%0 Book Section %1 statphys23_0649 %A Viot, P. %A Piasecki, J. %A Talbot, J. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K boltzmann dissipative equation gas granular statphys23 systems topic-7 %T Variety of shape of the velocity distribution of a granular planar rotator in a thermalized bath %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=649 %X Granular gases are systems in which macroscopic particles lose a fraction of their kinetic energy at each collision. When an external energy supply is continuously brought to the particles, the system may reach a non-equilibrium steady state, whose properties differ significantly from those of thermal equilibrium (breakdown of the equipartition, non-gaussian statistics, modified hydrodynamics). All those characteristics are intimately related to the dissipative nature of collisions. The studies of granular gases have focused mainly on spherical particles. However, anisotropy for granular particles is ubiquitous in nature, and one expects that the anisotropy introduces additional effects. We analyze, both numerically and analytically by means of the Boltzmann equation, the kinetics of a granular planar rotator with a fixed center undergoing inelastic collisions with bath particles. The angular velocity distribution displays a large variety of behavior: when the mass of the rotator is much larger than the mass of the bath particles, a perturbative method allows to solve the Boltzmann equation and shows that the distribution is quasi-Gaussian in this Brownian limit. Conversely, in the limit of an infinitely light particle, an exact solution is obtained when the coefficient of restitution is equal to zero. Intermediate cases are obtained by a precise numerical method showing strong deviations to gaussian behavior.

@incollection{statphys23_0649, abstract = {Granular gases are systems in which macroscopic particles lose a fraction of their kinetic energy at each collision. When an external energy supply is continuously brought to the particles, the system may reach a non-equilibrium steady state, whose properties differ significantly from those of thermal equilibrium (breakdown of the equipartition, non-gaussian statistics, modified hydrodynamics). All those characteristics are intimately related to the dissipative nature of collisions. The studies of granular gases have focused mainly on spherical particles. However, anisotropy for granular particles is ubiquitous in nature, and one expects that the anisotropy introduces additional effects. We analyze, both numerically and analytically by means of the Boltzmann equation, the kinetics of a granular planar rotator with a fixed center undergoing inelastic collisions with bath particles. The angular velocity distribution displays a large variety of behavior: when the mass of the rotator is much larger than the mass of the bath particles, a perturbative method allows to solve the Boltzmann equation and shows that the distribution is quasi-Gaussian in this Brownian limit. Conversely, in the limit of an infinitely light particle, an exact solution is obtained when the coefficient of restitution is equal to zero. Intermediate cases are obtained by a precise numerical method showing strong deviations to gaussian behavior.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Viot, P. and Piasecki, J. and Talbot, J.}, biburl = {https://www.bibsonomy.org/bibtex/23cf9dc85ba01b9e44e1f75a312c2c60e/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {10db8ad8e4c2daa78fab3132714d963d}, intrahash = {3cf9dc85ba01b9e44e1f75a312c2c60e}, keywords = {boltzmann dissipative equation gas granular statphys23 systems topic-7}, month = {9-13 July}, timestamp = {2007-06-20T10:16:25.000+0200}, title = {Variety of shape of the velocity distribution of a granular planar rotator in a thermalized bath}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=649}, year = 2007 }