Abstract
The purpose of this study is to find a method to accomplish rapid mixing in a small-scale channel. The relation between interface characteristics and mixing enhancement in a small-scale is investigated by an experiment and a numerical simulation. By comparing the results of the experiment to those of two-dimensional and three-dimensional numerical simulations, it is shown that it is essential to threat the flow field as three-dimensional. It is also shown that the interface length does not always predict the mixing enhancement, and it is important to stretch the interface where the concentration gradient is high.