Velocity distribution and velocity correlation of mixture of gases in a nanochannel

• A MD simulation to investigate interaction properties of mixture of gases.
• The collision rate varies linearly with logarithm of mass fraction.
• The Maxwell-type model predicts the reflected distributions from the surface.
• Velocity correlation shows a variation in accommodation properties.

Molecular dynamics study of non-reacting and disparate mass binary gas mixture is conducted. To investigate the gas–surface interaction properties of the gas mixture, in non-continuum regime, the rarefied gas confined in a nanochannel is considered. While keeping the bulk number density a constant, the interaction properties of gas mixtures at different molar concentration of individual components are determined. The study discusses the calculation of accommodation coefficients and prediction of the reflected gas distribution using accommodation coefficients. The Maxwell-type model that use calculated values of accommodation coefficients accurately predicts the reflected tangential and normal distributions. The model is validated for different wall-fluid conditions. The velocity correlation of individual gases demonstrates that the individual components of gas mixture are accommodated in different proportion. The result from the study will be beneficial in the analysis and development of potential applications involving the flow of gas mixture in a nanochannel.