Determining the porous medium parameters of a hollow fiber hemodialyzer using computational methods alone.*

Hollow fiber hemodialyzers are cylindrical units that contain thousands of hollow fibers. The dialyzer fluid (dialysate) enters perpendicularly through the inlet dialysate port, gets distributed circumferentially and passes axially outside the hollow fibers in the shell region of the dialzyer. The dialysate exits the dialyzer through outlet port in the similar fashion as it entered. Due to its complex geometry, studies have treated the dialysate flow domain as a porous medium. However, these studies have had to rely on experiments to find the porous medium characteristics such as the permeability. For the first time, by performing 3D Navier-Stokes simulations of the dialysate flow, in conjunction with parametric 2D axisymmetric porous media simulations of flow through the same domain, we have developed a method for finding porous medium parameters such as the axial and radial Darcy’s permeability parameters for a given dialyzer, solely using computational methods.