Drift velocity of a Smoluchowski gas: a numerical demonstration of the fluctuation-dissipation theorem.
This Brief Report shows that the Smoluchowski thermostat, a stochastic boundary condition used to mimic a diffusive gas-wall collision, produces the correct stationary nonequilibrium states. The stationary states are generated by placing an ideal gas coupled to a Smoluchowski thermostat in a constant external field. It is shown by simple numerical simulations that the resulting drift velocity is compatible with the definition of the gas particle mobility, satisfying the well-known fluctuation-dissipation theorem. As an interesting application, it is shown that species that are chemically identical but differ in surface momentum accommodation can be separated effectively in the Knudsen regime.
Verbeek
Martijn G
MG
Dibbitsstraat 12, 1689 EE Zwaag, The Netherlands. gustafverbeek@gmail.com