T型微混合器混合特性的浓度分布评价法

Concentration Distribution Evaluation Technique for T-shaped Micromixer

提出一种微混合器混合性能的评价方法。在样品盒中注入不同浓度罗丹明B溶液并用体视显微镜观察捕获图像,通过ImageJ软件读取图像灰度值,建立不同深度下溶液的浓度-灰度值函数关系,运用此关系式将T型微混合器3种不同深度(0.1、0.2和0.4mm,质量浓度0.05%的罗丹明B溶液和去离子水作为配对流体)混合实验中捕获的图像中各像素点上的灰度值转换为浓度值,绘制浓度等高线图及浓度频数分布图,分析各自混合情况,最后引入浓度混合指数概念及计算公式,分析3种深度混合器内不同截面上的混合程度。此方法从定性和定量两方面分析了微尺度下混合腔深度对微混合的影响程度,具有一定的应用价值。

An improved technique is presented to characterize the micromixer. Rhodamine B solutions with different concentration were injected into different sample mixers. The images were captured by stereo- microscope with charge coupled device and converted into grey-scale values by Image J. Then the relationships between grey-scale value and concentration were obtained in different depths. According to the relationships, the mixing images were converted to concentration contour maps to token the different concentration fluid distribution in the mixing cavity, while the concentration frequency analyses were also implemented based on histogram. The concentration mixing index was introduced to analyze the mixing efficiency on different sections. The qualitative and quantitative analyses on the mixing characterization for the micromixer were discussed in detail in the micro scale.