Relationship between Maxwell Boundary Condition and Two Kinds of Stochastic Thermal Wall

摘要

The relationship between Maxwell boundary condition used in kinetic theory and two kinds of stochastic thermal wall used in molecular dynamics simulations is studied analytically. It is proved that one of the thermal walls is equivalent to Maxwell boundary condition by the detailed analysis of mass, momentum and energy conservation laws at a boundary. A new thermal wait, which takes into account both the probability of the thermalization of an incident particle at a boundary and the motion of the wall, is proposed. As a typical example, a temperature jump at a boundary of a stationary one-dimensional system is also derived explicitly.