Flow response of a segregating mixture by interacting lattice gas simulation

Steady-state flow and structural profiles of immiscible components A and B (molecular weights MA and MB, MA<MB) in a non-conservative open system are studied by an interacting lattice gas Monte Carlo simulation. Concentration gradient and hydrostatic bias H drive the constituents (A,B) which are continuously released from the bottom with equal probability against gravity. At low bias, the segregation of A and B leading to a partial layering is enhanced toward the bottom. The longitudinal density profile with a high density in the bottom region and low toward the top shows linear, exponential, and power-law decays in different regions of depth or altitude which varies systematically with the pressure bias. The transverse density profiles show segregation with different domain sizes and layering depending on the bias. Response of their steady-state flux density j to the hydrostatic bias H is found to be linear at higher bias. The difference in response of the flux density of the two components becomes more pronounced at low bias and higher miscibility gap.