Lyapunov instability of rough hard-disk fluids

Autor(en)

Jacobus A. van Meel, Harald Posch

Abstrakt

The dynamical instability of rough hard-disk fluids in two dimensions is characterized through the Lyapunov spectrum and the Kolmogorov-Sinai entropy hKS for a wide range of densities and moments of inertia I. For small I the spectrum separates into translation-dominated and rotation-dominated parts. With increasing I the rotation-dominated part is gradually filled in at the expense of translation until such a separation becomes meaningless. At any density, the rate of phase-space mixing, given by hKS, becomes less and less effective the more the rotation affects the dynamics. However, the degree of dynamical chaos, measured by the maximum Lyapunov exponent, is only enhanced by the rotational degrees of freedom for high-density gases but is diminished for lower densities. Surprisingly, no traces of Lyapunov modes were found in the spectrum for larger moments of inertia. The spatial localization of the perturbation vector associated with the maximum exponent however persists for any I.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

University of Amsterdam (UvA)

Journal

Physical Review E

Band

80

ISSN

1539-3755

DOI

https://doi.org/10.1103/PhysRevE.80.016206

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/b2eb4366-d28c-4828-9160-b482143f696c