Hydrodynamic relaxation of the adiabatic piston

Abstract

We derive a closed deterministic equation for the motion of the two-dimensional adiabatic piston. It predicts a damped oscillatory motion of the piston towards a final rest position, which depends on the initial state. In the limit of large piston mass, the solution of this equation is in quantitative agreement with the results obtained from both hard-disk molecular dynamics and hydrodynamics.