Geometrical influence on mixing in helical porous membrane microcontactors

The goal of gas–liquid micromixing has led to develop various kinds of passive micromixer configurations, which can be used for many microfluidics applications. This work details gas–liquid contacting using porous helical microchannels. An experimental and numerical design methodology for different geometrical configurations is presented which systematically integrates computational fluid dynamics (CFD) with an optimization methodology based on the use of design of experiments (DOE) method. The methodology investigates the effect of geometric parameters on the mixing performance of helical membrane microchannel that has design characteristics based on the generation of secondary vortices. The methodology has been applied on different designs of helical hollow fiber geometry at several Reynolds numbers. The geometric features of this microchannel geometry have been optimized and their effects on mixing are evaluated. The flux enhancement and degree of mixing are the performance criteria to define the efficiency of the gas–liquid microchannel contactor for different design requirements. Due to its ease of fabrication, efficiency and operational flexibility, helical membrane micromixers are favorable for gas–liquid contacting, water oxygenation, pervaporation, etc. -------------------------------------------------------------------------------