Simulation de la diffusion des gaz dans les capillaires en régime de Knudsen

Abstract

Consideration of ideal gas diffusion under a pressure gradient and in Knudsen regime conducted to the definition of a parameter called the transported gas fraction. This fraction defines the ratio of the diffused particles to the total amount of gas entering into the diffusion path. A capillary defined by a cylindrical tube whose axis is perpendicular to the inlet or outlet (Configuration 1) was considered as the diffusion path and then the computer simulation of gas diffusion in Knudsen regime was carried out by a Monte-Carlo method. Good agreement between simulation and theoretical formulation for the transported gas fraction confirms the validity of the simulation. Following this agreement, the Knudsen diffusion in the cylindrical tube with oblique inlet or outlet (Configuration 2) was simulated. Using the simulation results for the configuration 2, the tortuosity factor for this configuration was obtained. Copyright © 2007, Institut français du pétrole.