Wed October 26th 2011
16:00
ZH286
Seminar A granular ratchet: Spontaneous symmetry breaking and fluctuation theorems in a granular gas
Devaraj van der Meer

Details:

We construct a ratchet of the Smoluchowski-Feynman type, consisting of four
vanes that are allowed to rotate freely in a vibrofluidized granular gas. The necessary out-of-equilibrium environment is provided by the inelastically colliding grains, and the equally crucial symmetry breaking by applying a soft coating to one side of each vane. The onset of the ratchet effect occurs at a critical shaking strength via a smooth, continuous phase transition. For very strong shaking the vanes interact actively with the gas and a convection roll develops, sustaining the rotation of the vanes. From the experimental results we show that a steady state fluctuation relation holds for the work injected to the system, and that its entropy production satisfies a detailed fluctuation theorem. Surprisingly, we find that the above relations are satisfied even when a convection roll has developed and there exists a strong coupling between the motion of the vanes and the granular gas.
Go back to the agenda.

The 10th Complex Motion in Fluids 2020
Max Planck Gesellschaft
MCEC
Twente
Centre for Scientific Computing
Facebook
YouTube