Knudsen Effect in a Nonequilibrium Gas

TL;DR

This paper investigates the Knudsen effect in a nonequilibrium gas through molecular dynamics simulations, revealing how pressure differences depend on heat flux direction and deriving boundary layer velocity distributions.

Contribution

It provides the first detailed boundary layer analysis of the Knudsen effect in a nonequilibrium gas, combining simulations with theoretical velocity distribution functions.

Findings

Pressure difference depends on heat flux direction

Theoretical boundary layer velocity distribution matches simulations

Confirmed the Knudsen effect in nonequilibrium conditions

Abstract

From the molecular dynamics simulation of a system of hard-core disks in which an equilibrium cell is connected with a nonequilibrium cell, it is confirmed that the pressure difference between two cells depends on the direction of the heat flux. From the boundary layer analysis, the velocity distribution function in the boundary layer is obtained. The agreement between the theoretical result and the numerical result is fairly good.