Estimation of the flows mixing efficiency inside T-micromixer with an external perturbation for low Reynolds numbers

The flow pattern regimes and mixing quantities in case of an external perturbation for low Reynolds numbers in a T-shape microchannel were studied experimentally using the LIF technique. Formation of a hydrodynamic wave travelling along the outlet channel for the stratified regime was discovered. The wave amplitude is 0.057W out. The wavelength corresponding to distance between two nearest pits is 3.86D h. The change of mixing efficiency between undisturbed and perturbated flows in each of the considered sections is less than 6%. However, the arising of wave causes a decrease in the distance at which the flows are completely mixed.