Numerical validation of the dusty-gas model for binary diffusion in low aspect ratio capillaries

The dusty-gas model is an empirical formulation commonly used to describe gas flows in porous media. While experiments have validated the model for pores with high aspect ratios, a validation for near-unity aspect ratios is lacking. We used direct simulation Monte Carlo to evaluate the accuracy of the dusty-gas model for binary diffusion in low aspect ratio capillaries. Our results suggest that the dusty-gas model deviates from the Monte Carlo simulations by less than 3% for aspect ratios >= 1, thus supporting its suitability as a phenomenological model for transport in nanoporous structures in various applications such as heat transfer, catalysis, and water purification. (C) 2021 Author(s).

Automated summary

The dusty-gas model is commonly used to describe gas flows in porous media, with experiments validating its accuracy in high aspect ratio pores but lacking validation for near-unity aspect ratios. This study used direct simulation Monte Carlo to evaluate the model's accuracy for binary diffusion in low aspect ratio capillaries, finding that the model deviates by less than 3% from Monte Carlo simulations for aspect ratios >= 1, supporting its suitability for various applications in nanoporous structures.