Abstract
The interface of side-by-side two layered laminar flows largely distorts as influenced by the inertial forces in a curve of the microchannel. Computational fluid dynamics simulation and three-dimensional observation of fluid using confocal fluorescence microscopy revealed the distortion. Such a phenomenon has at least two kinds of effects. One is the increase of the interface area of two miscible liquids compared with the straight channel. Such an effect is important since it promotes efficient mixing in a laminar flow which does not allow turbulent mixing. The other effect appears in the handling of the substance in the interface such as chemical reaction products. Because the amount of displacement of the interface depends on the mass of material in the solution, the distribution of substances such as macromolecules in the solvent varies after passing through the curves. This phenomenon results from the property of the secondary flow which occurs at the curve in a rectangular channel, that is, according to the dynamics of the Dean vortices. This development indicates that the reaction products localizing at the interface of reaction solvents are unevenly distributed at curves in the microchannels, and suggests the possibility of the influence of such phenomenon on analytical methods.
