CFD study of the effect of SWM feed spacer geometry on mass transfer enhancement driven by forced transient slip velocity

Recent studies have shown that the interactions between forced transient flow and eddy inducers (i.e. spacers) in spiral wound membrane modules results in significant mass transfer enhancement and reduction in concentration polarisation (CP). This paper uses CFD to investigate the effect of varying the spacer geometric parameters on the resonant frequency for an unsteady forced-slip, as well as the resulting permeate flux enhancement, for a 2D zig-zag spacer. The analysis shows that the resonant frequency is significantly affected by the interaction of the shear layer with successive downstream spacers. The effectiveness of forced-slip reaches a peak (up to 15.6% flux increase) for a spacer size in the range of 0.5