Refined Assessment of the Impact of Membrane Module Channel Curvature on Pressure Drop

Spacers are key components of membrane modules that significantly influence the performance of membrane separation processes and the value of pressure drop. The development of computational fluid dynamics (CFD) methods promoted a significant increase in investigation dedicated to improving spacer designs. However, some issues in this field remain controversial. One of them is the reasonability of the application of flat models during analysis processes in spiral-wound modules. In the current work, the CFD investigation of the influence of channel curvature on pressure drop was carried out using the open-source software package OpenFOAM-v2212. It was found that within the range of radii of curvature from 0.01 m (10 mm) to 0.025 m (25 mm) and lengths from 0.008 m (8 mm) to 0.015 m (15 mm), the discrepancy does not exceed 10%. Thus, the flat model can be considered an acceptable approximation of real conditions in spiral-wound module channels, particularly during the investigation of new spacer designs. However, if the observed effect does not exceed 7–10%, investigations that consider the channel curvature are advisable. The assumption about the existence of a critical value for the channel’s radius of curvature was not confirmed. The influence of the mesh dimensions on the accuracy of simulation results was evaluated.