SIMULATION OF CROSS-FLOW FILTRATION FOR BAFFLED TUBULAR CHANNELS AND PULSATILE FLOW

Membrane filtration, for a baffled tubular system, has been rigorously simulated for Reynolds numbers up to 200. Concentration polarization effects have been included. Wall and central baffles with and without the addition of pulsations are the four cases considered. The numerica l simulation generates the flow field by solving the time-dependent Na vier-Stokes equations. Then the local flux, pressure and the wall conc entration along the membrane are calculated by mass balances and an os motic pressure model using the pre-generated flow field and a relation ship between the mass transfer coefficient and the shear stress. Compa risons between the different geometrical arrangements and hydrodynamic conditions are drawn on a flux and power density basis. The addition of pulsations improved the fluxes, the relative improvement being grea ter for the wall baffles. The absolute values of the predicted fluxes were greater for the central baffles.