Determination of the Wall Shear Stress by Numerical Simulation: Membrane Process Applications

Abstract

Membrane processes have been intensely developing during the last decades, and mainly in dairy industry. Considering the feed effluent complexity, concentration polarization phenomenon and fouling are accentuated limitations for the development of membrane dairy filtration processes. Knowledge of the wall shear stress developed at the membrane surface is fundamental to reduce those phenomena. In this work, the variation of the wall shear stress on cylindrical, square, triangular and hybrid channels by numerical simulation for various operating parameters was studied. Predictions were established for different commercial ceramic membranes and predict the geometry that tends to better mass transport efficiency by enhancing hydrodynamics conditions. Numerical simulations are performed over a typical range of Reynolds numbers inside different channel geometries under laminar and turbulent conditions. Consequently, this paper intended to enhance the performances of these processes by maximizing the average wall shear stress on the membrane surface by numerical simulation. A comparison with experimental results was realized and a good agreement was obtained. Given those conclusions, a new membrane according to the whole CFD results consistent with experimental results was designed.

Numerical and experimental methodology for the development of a new membrane prototype intended to microfiltration bioprocesses. Application to milk filtration

“…By default, for tangential filtration experiments, the inlet and outlet pressure values were, respectively in the range of: P i = [2.2-2.7] bar and P o = [0.5-1.0] bar, being equivalent to a global TMP of 1.35 bar and a tangential fluid velocity of 5 m s −1 . Results similar to literature were obtained [8,11,12,23,24].…”

“…Gésan-Guiziou et al [10] and later Mercier-Bonin et al [1] investigated the influence of the shear stress in the case of a gas/liquid fluid flow applied to skimmed milk microfiltration with a 0.1 m membrane nominal pore size. Later, the effect of the shear stress on membrane filtration performance during milk microfiltration and ultrafiltration were demonstrated [11,12]. The tangential fluid flow is a dominant factor, controlling the deposit and the filtration cake erosion [13].…”

Effect of Modifying the Membrane Surface with Microcapsules on the Flow Field for a Cross-Flow Membrane Setup: A CFD Study

“…A review on this problem for pressure-driven membrane systems was given by [ 48 ]. Many studies tried to enhance the wall shear stress to reduce the accumulation at the surface of the membrane [ 39 , 47 , 49 ]. In [ 50 ], the wall shear stress for hollow fiber membrane modules was investigated and different module configurations were compared.…”