Details of Research Outputs

This presentation aims to introduce three novel methods for assessing the distribution uniformity of bubbles and determining their mixing time to uniformity. These uniform design based methods are illustrated through image analysis in a direct-contact heat exchanger (DCHE). The novelties include the little constraint of final evaluation value and the efficient algorithm of bubble centroid, leading to fast and accurate characterization of mixing uniformity. To determine the effects of resolution aspect (considering two types of aspect ratios: 16:9 and 4:3) and local region on the measurement, various evolutions of bubbles movement and three mixing measures in the DCHE are investigated experimentally. Real experiments and simulations are conducted, showing that the proposed methods outperform the existing methods such as Betti number. It is also shown that the location effects of bubbles can be measured successfully using these discrepancy measures, which brings a new insight into the comparison of mixing state of different systems.