Mass flow and momentum flux in nanoporous membranes in the transitional flow region.

ABSTRACT: An experimental study of momentum transfer in nanoporous polymeric track-etched membranes with pore diameters ranging from 100 to 1300 nm and nanochannel lengths of 12-20 μm was performed using He, N₂, CO₂, and SF₆ propellants in a wide range of plenum and background pressures. Mass flux through the membranes was elaborated as a combination of Knudsen diffusion and viscous flow at Knudsen numbers above 0.1 and become choked at lower Knudsen numbers. The discharge coefficient for the membranes attained was 0.6, making the permeation rate similar to that of thin orifices. The effect is attributed to the mirror reflection of the molecules from the pore walls at low angles of incidence. The exhaust gas velocity is found to be dependent on the plenum to backgrou

SUBMITTER: Podgolin SK 

PROVIDER: S-EPMC8489186 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature