气液环状流时空流动结构及流动特性光学诊断新方法研究

The diagnosis，analysis and prediction of flow structure and flow characteristics in gas-liquid annular flow, are of great importance on theoretical research and application. A novel solution to visualization measurement of temporal-spatial flow structure of annular flow is proposed, and the key technologies are studied. A novel scanning laser-based fluorescence (SLIF) method is presented. Combined with the stereo high-speed photography, error analysis of optical path and the distortion correction, the new optical diagnosis platform is set up and optimized，which breaks through the limitation of temporal and full spatial measurement for liquid film in the longitudinal and circumferential directions and entrainments simultaneously. A feature-based method with calibration is developed for flow information processing, and the film thickness, wave velocity and other statistical characteristics are obtained. According to the complex pattern feature of disturbance wave, ripple wave on the gas-liquid interface and so on, the temporal-spatial flow structure of the liquid film in the longitudinal and circumferential directions, evolution and the gas-liquid interaction mechanism under various flow conditions are established and analyzed. The flow regime discrimination and prediction method based on the multiple parameters integration is presented. The reasonable and progressive experiments are performed to analyze the flow structure and characteristics, and the prediction models of liquid film thickness and distribution are optimized. The project would provide a novel approach on non-intrusive, temporal-spatial diagnosis with high precision for the annular flow, and a novel research tool to understand the annular flow characteristics and mechanism in the scientific research and industrial applications.

气液环状流流动结构与流动特性的诊断、分析和预测具有非常重要的研究意义和应用价值。本项目针对环状流时空流动可视化测量提出新的解决思路，并围绕关键技术进行研究。提出扫描激光诱导荧光新方法，结合体视高速摄影、光路误差分析及畸变校正建立和优化光学诊断平台，突破传统流场无法同时实现液膜轴向、周向，夹带液滴、气泡等全时空有效测量的局限性。提出基于校准和特征的流场信息处理方法，获取高精度液膜厚度、波速及其他统计特征；基于气液界面干扰波、纹波等复杂模式波动特征，建立并分析不同工况下液膜沿轴向及周向截面时空流动结构、演化特性以及气核液相作用机理，提出多参数融合的环状流流型分析及预测方法；通过合理、递进的实验手段对环状流动结构和特性进行分析，并优化液膜厚度与分布预测模型。本项目将为实现环状流动特征非侵入、高精度、四维时空诊断提供新的技术途径，并为科学研究和工程应用中深入认识环状流动特性和机理提供新的研究手段。

针对目前气液环状流非侵入、全流场、高分辨率诊断方法的不足和应用局限性，围绕时空流动特征光学诊断和流动特性分析提出一系列新的解决思路，并对关键技术进行了深入研究。针对流场中液膜轴向、周向，夹带液滴、气泡等全时空有效测量，结合体视高速摄影、光路误差分析及畸变校正建立和优化了光学诊断平台；提出了基于校准和特征的流场信息处理方法，获取了高精度液膜厚度、波速及其他时、频域统计特征；基于气液界面干扰波、纹波等复杂模式波动特征，建立并分析了不同工况下液膜沿轴向及周向截面的时空流动结构、演化特性以及气核液相作用机理，定量探究了水平环状流中顶部液膜的形成机理，分析了液膜表面液相夹带产生的动力学过程；通过合理、递进的实验手段对降膜，竖直向上、竖直向下、水平环状流以及过渡流型的流动结构和特性进行了分析，优化了不同流型流态下液膜厚度与分布预测模型；在气液环状流流场诊断基础上，进一步实现了液膜温度场的可视化测量以及传热传质耦合分析。本项目为实现环状流动特征非侵入、高精度、四维时空诊断提供了新的技术途径，并为科学研究和工程应用中深入认识环状流动特性和机理提供了新的研究手段。围绕本项目研究内容，授权国家技术发明专利4项，在国内外核心刊物和国家会议上发表学术论文21篇，研究成果发表于一区TOP期刊International Journal of Heat and Mass Transfer，测试测量领域权威期刊IEEE Transactions on Instrumentation and Measurement, IEEE Sensors Journal, Measurement，以及传热传质领域权威期刊Experimental Thermal and Fluid Science等，参加了2017、2019和2020 IEEE International Instrumentation and Measurement Technology Conference国际会议，并做报告。培养硕士研究生10名，博士研究生在读2名。