高速气流作用下液膜在预膜板结构唇边破碎机理研究

The two-phase hydrodynamic process of liquid breakup into droplets is not only a matter of scientific problems, but also a key technology for many engineering applications. In this project, experimental study and numerical simulation will be used to investigate the breakup phenomenon of continuous liquid film at structured lips of the prefilming plate and in its vicinity under the effect of double-sided high-speed airflow. A series of experiments will be performed to observe the flow of liquid film over prefilming plate, the primary breakup of liquid bags at the structured lips, and the secondary breakup of liquid ligaments in its vicinity. On the basis of the experimental data analysis and processing, the breakup mechanism of the liquid film at the structured lips will be theoretically explained, and the influence of the size and shape of the prefilming plate lip on the liquid film breakup and the favorable factors will also be revealed. Then, the physical and mathematical models of the primary breakup of liquid bags at structured lips of the prefilming plate and the secondary breakup of ligaments in its vicinity will be established. A mass-conserved level set interface tracking method will be developed. Combined with the lattice Boltzmann method and large eddy simulation method, a multi-scale numerical calculation platform will be built to accurately reproduce the physical phenomenon of the liquid flow over the prefilming plate at structured lips. By comparing with the experimental results, the established model and computation method can be modified. Therefore, the physical and mathematical models of liquid film breakup at the structured lips and in its vicinity of the prefilming plate will be established and applied to investigate the breakup process of liquid film. The work will lay the foundation for the design of the corresponding prefilming airblast nozzles.

液体破碎成微小液滴的两相流体动力学过程不仅蕴含许多科学问题，也是许多工程应用领域的关键技术。本项研究拟采用可视化实验和数值模拟相结合的方法研究在双侧高速气流作用下，连续液体在预膜板结构唇边及尾部的破碎现象。实验观测液膜在预膜板上的流动、液袋在结构唇边一次破碎和唇边尾部液丝二次破碎过程。在实验数据处理分析基础上，理论阐释结构唇边液膜破碎机理、探寻预膜板结构唇边尺寸和形状对液膜破碎的影响规律和有利的因素。建立结构唇边液袋一次破碎以及结构唇边尾部液丝二次破碎物理数学模型,发展质量守恒的水平集界面追踪方法，联合格子Boltzmann方法、大涡模拟方法，构建准确再现液膜在预膜板结构唇边破碎物理现象的多尺度计算平台。将数值模拟结果与实验结果进行比较，修正模型和计算方法，获得能够描述液膜在预膜板结构唇边及尾部破碎的物理数学模型，系统模拟和分析液膜破碎的全过程，为实现相应预膜气动雾化喷嘴的设计奠定基础。

液体破碎成微小液滴的两相流体动力学过程不仅蕴含许多科学问题，也是许多工程应用领域的关键技术。本项研究采用可视化实验和数值模拟相结合的方法研究在双侧高速气流作用下，连续液体在预膜板结构唇边及尾部的破碎现象。实验观测液膜在预膜板上的流动、液袋在结构唇边一次破碎和唇边尾部液丝二次破碎过程。在实验数据处理分析基础上，理论阐释结构唇边液膜破碎机理、探寻预膜板结构唇边尺寸和形状对液膜破碎的影响规律和有利的因素。建立结构唇边液袋一次破碎以及结构唇边尾部液丝二次破碎物理数学模型,联合格子Boltzmann方法、大涡模拟方法，构建准确再现液膜在预膜板结构唇边破碎物理现象的多尺度计算平台。获得了液体在结构唇边预膜板上的破碎模式，雾化液滴的分布状态，提出了雾化质量的优劣评判标准，确定了预膜板结构唇边最优形状特点，研究表明矩形结构唇边预膜雾化喷嘴的雾化质量最佳。在本项目资助下，共发表期刊论文22篇，其中SCI检索19篇，EI检索20篇（含双检索）。会议论文2篇。2名博士研究生、5名硕士研究生顺利完成答辩并获得学位。