Pore-Scale Study of Rarefied Gas Flows Using Low-Variance Deviational Simulation Monte Carlo Method

Gaseous flow through ultra-tight porous media, e.g. shale and some high-performance insulation materials, is often rarefied, invalidating an analysis by the continuum theory. Such rarefied flows can be accurately described kinetic theory of gases which utilizes Boltzmann equation its simplified models. While discrete velocity methods have been successful in directly solving these equations, immense potential a particle-based solution variance-reduced Boltzmann-BGK (Bhatnagar–Gross–Krook) for media has not exploited yet. Here, parallel solver based on low variance deviational simulation Monte Carlo method developed 3D flows, enables pore-scale simulations using digital images samples. The unique advantage this formulation providing additional insights regarding multi-scale nature surface/gas interactions via two new parameters, i.e. pore surface activity, respectively. Together, parameters identify key properties media. computational efficiency accuracy current also analysed, suggesting that powerful tool to quantify