Spiral wound membrane is used in several industrial purification processes such as desalination, food industries and gas separation. It has been shown that membrane performance could be greatly enhanced by momentum mixing in the feed channel induced by spacers. Square shaped spacers will be considered in inline geometries for the Reynolds number, Re, of 300 and 500. A separation of CO_2 from CH4 will be investigated. A computational fluid dynamics simulation will be conducted for flows of a binary mixture of CO_2 and CH_4. The mass flux through the membrane will be determined based on the local partial pressures of each species, the permeability, and the selectivity of the membrane. Shear Stress Transport turbulence model will be employed to capture the steady state velocity and concentration field. The transient effect on the momentum mixing will be studied using lattice Boltzmann method. Two dimensional nine velocity directional, D2Q9, lattice arrangement with multi-relaxation time (MRT) lattice Boltzmann method is used to simulate transient flow field while single relaxation time (SRT) lattice Boltzmann method is employed to simulate concentration field for Re = 100 and 300. The bounding surfaces are treated as impermeable walls for simulations conducted using the lattice Boltzmann method. The results predicted by lattice Boltzmann and SST turbulence model agree well.
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