Rarefied gas flow through nanoscale tungsten channels

• We have studied argon flow nanoscale channels by molecular-dynamics method.
• We examined influence of roughness of channel's wall on parameters of argon atoms colliding with it.
• Nonlinear correlation between length of the channel and flow rate has been observed in case of short channel.
• Limited applicability of Maxwell's boundary conditions has been observed.

The aim of this work is to investigate argon flow behaviors through the channels with three types of boundary conditions. Current work deals with numerical simulations of rarefied gas flow through nano-channels using the Molecular Dynamics method. Taking into account that this method is very time consuming, we implemented all the simulations using CUDA capable graphic cards. We found that the well-known and relatively simple Maxwell model of boundary conditions is able to reproduce gas flow through a tungsten channel with irregularities and roughness, while it results in a significant error in the case of a smooth metal surface. We further found that the flow rate through a relatively short channel correlates nonlinearly with the channel's length. This finding is in contrast with the results available in extant literature. Our results are important for both numerical and theoretical analyses of rarefied gas flow in micro- and nano-systems where the choice of boundary conditions significantly influences flow.

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