چكيده لاتين :
This research demonstrates the mixing of two -dimens ional, time-dependent elestro-osmot ic flows in a T-shaped microcharmel via the application of a rectified AC electric field at one inlet channel and a DC electric field at the other. By speci fying appropriate electric fie ld intensities at the two inlets, a momentum imbalance is induced at the interface betwee n the two fluid streams. This imbalance prompts the formation of a periodic waveform at the interface, which propagates in the downstream direction, resulting in an enhanced mixing of the two species . The characteristics of the micromixer are investigated by performing a series of numerical simulations using the backwards-Euler time-stepping scheme . The results show that the relative proportion of
the two fluid streams enter ing the mixing channel can be adjusted by reg ulat ing the difference in intensity of the two electric fields. For a give n AC electr ic field, two threshold va lues of the DC electr ic field intens ity are found, corresponding to fully-mixed dimensionless concentrations of zero (upper inlet fluid only) and one (lower inlet fluid only), respective ly. The dimensionless concentration obta ined at DC intensities between these two threshold values varies linearly with the difference in intensity of the two electr ic fields, but is independent of the frequency of the AC electr ic field. Finally, vary ing the width of the mixing channe l has no significant effect on the mixing performance (provided that the mixing length is adequately extended) and results in no more than a minor expansion of the linear range bounded by the two DC voltage thres hold va lues .
