Theoretical Study of the Aerodynamic Drag Force of a Nanofiber/Microfiber Mixed Aerosol Filter

The problem of incompressible gas flow in a periodic cell with one microfiber and many nanofibers as an element of the porous structure of a mixed-type aerosol filter has been solved. The flow in a nanofiber medium around a single microfiber is described using the Darcy and Brinkman models. The boundary value problems for both models were solved analytically and numerically for circular and rectangular periodic cells, respectively. A microscopic Stokes model has been developed in the interpore space of a periodic cell, taking into account the slip condition on the surface of nanofibers. Analytical formulas are obtained for the aerodynamic drag force of a periodic cell and the drag forces of microfiber and nanofibers. The obtained formulas are in good agreement with the results of the microscopic model. The dependencies of the drag forces on the cell porosity and the mass fraction of nanofibers have been studied.