Study of the Effect of Spacer Orientation and Shape in Membrane Feed Channel using CFD Modelling

Computational fluids dynamics (CFD) modelling has been carried out for a spacer-filled membrane channel using ANSYS FLUENT 14.0. The effect of spacer angles relative to the feed flow direction and different spacer shape combinations on velocity magnitude, wall shear stress, pressure drop and power number were investigated. From the results, spacer angle of 63.565 is the best orientation as it can generate the highest shear stress and reasonably lower power number compared to other spacer angles. Although the combinations of spacer shape did not significantly improve the average wall shear stress, it helped in reducing the pressure drop of the channel. The combination of triangular and circular spacers provided lower Power number, and hence lower energy consumption was required compared to pure triangular spacer. The current results indicated that a combination of triangular and circular spacers can be employed to offer better saving in energy consumption.