Laminar flow in channels with porous walls, revisited

An analytical solution for the pressure drop in fluid flow in a rectangular slit and cylindrical tube with porous walls is presented for the case, of constant wall permeability. It is shown that model predictions for the part icular case of constant wall velocity for rectangular slit with permeable w alls agrees very well with Berman's solution [J. Appl. Phys. 24 (1953) 1232 ]. The derivation presented in this work leads to analytical expressions fo r pressure drop as a function of wall permeability, channel dimension, axia l position and fluid properties. These analytical expressions for constant wall permeability could be used to benchmark numerical routines for fluid f low modeling past semi-permeable membranes and for quick engineering estima tes for pressure drop in cross-flow membrane modules. (C) 2001 Elsevier Sci ence B.V. All rights reserved.