Study on the influence of feed spacer dimensions and structure on permeation characteristics of reverse osmosis membranes

A D2Q9 discrete velocity model within the multiple-relaxation-time framework is developed using the lattice Boltzmann method, coupled with boundary conditions that accurately capture membrane permeation characteristics. Numerical simulations are performed by incorporating feed spacers into unobstructed flow channels, systematically analyzing the effects of spacer structural configurations and dimensional parameters on hydrodynamics and mass transfer performance. The computational results reveal that spacer dimensions and geometric configurations differentially affect reverse osmosis performance, with larger spacer dimensions leading to more pronounced enhancements in flow disturbance intensification and membrane separation efficiency. Among the three spacer geometries (triangular, elliptical, and quadrilateral), the triangular spacer demonstrates the best performance in membrane separation processes, while elliptical and quadrilateral spacers show minimal differences in their effects on separation efficiency.