Pressure Decay in 2D Molecular Dynamics Simulation with Varied Filter Pore Width and Fluid Impurity Diameter

Time dependent pressure in a 2D molecular dynamics model using Lennard-Jones Argon atoms is studied in a semi-periodic chamber containing a simple porous filter. In each case an initial velocity bias towards the filter leads to the buildup of pressure in a region adjacent to the filter. The pressure in this region is shown to exhibit damped oscillatory behavior as the pulse is reflected and travels across periodic boundary conditions. The effects of pore width and fluid impurity diameter on the exponential decay time constant are evaluated in detail. Our results demonstrate a negative linear relation between time constant and pore width for systems with a fixed impurity diameter, and a positive linear relation beetwen time constant and impurity diameter in systems with a fixed pore width.