Optimization of a split and recombine micromixer by improved exploitation of secondary flows

Flow pattern in two split and recombine (SAR) micromixers were experimentally studied by mu-LIF measurements to validate corresponding CFD simulations. The original design of the investigated micromixer type is based on the repetition of identical SAR segments of a specific geometry. Aside a micromixer following this original design, the second micromixer investigated alternates two SAR segments versions, one being the original one, the other being an inverted and rotated version of it. The results of the simulations indicate that the secondary flows developing in the original design reduce the mixing performance for Re < 700. This knowledge and the improved understanding of the mixing principle in this specific kind of SAR micromixer was used to develop the design of an optimized version of this split and recombine micromixer type for Re < 700.