Study of the Effect of Geometry on Wall Shear Stress and Permeate Flux for Ceramic Membranes: CFD and Experimental Approaches

International audienceKnowing how wall shear stress develops at the membrane surface is extremely useful when trying to reduce concentration polarization and fouling. Newly developed as well as manufactured ceramic membranes exhibit various channel geometries (cylindrical, square, triangular, etc). Mass transport characteristics depend on the geometry that conditions hydrodynamic conditions. The goal of this work is to study the influence of the channel geometry on the wall shear stress for various operating parameters (tangential velocity, transmembrane pressure…). Numerical simulations are performed for various inlet velocities for different channel geometries. The wall shear stress along the channel perimeter as a function of the shape and the cross section of the channel are studied. The influence of the geometry on the membrane performances is also studied. The simulated shear stress is employed to correlate experimental results. The results of this comparison show that mass transfer resistance depends on the wall shear stress alone, regardless of the flow rate, the shape or section of the channels