Critical exponents for granular phase transitions
Fachbereich Physik, Philipps-Universität,
Renthof 6, D-35032 Marburg, Germany
Accepted: 31 October 1997
The solid-fluid phase transition of a granular material shaken horizontally is investigated numerically. We find that it is a second-order phase transition and propose two order parameters, namely the averaged kinetic energy and the averaged granular temperature, to determine the fluidization point precisely. It scales with the acceleration of the external vibration. Using this fluidization point as critical point, we discuss the scaling of the kinetic energy and show that the kinetic energy and the granular temperature show two different universal critical-point exponents for a wide range of excitation amplitudes.
PACS: 46.10.+z – Mechanics of discrete systems / 81.05.Rm – Porous materials; granular materials / 02.70.Ns – Molecular dynamics and particle methods
© EDP Sciences, 1997