自由面滚波影响下超疏水球面液膜流动机理研究

考虑超疏水和自由面滚波共同影响下的液膜流动问题鲜有研究，通过建立理论模型研究该问题可深化对液膜流动机理的认知，同时为超疏水材料在实际工程中应用的有效性提供理论依据。..本项目采用理论分析和模型实验两个途径研究超疏水球面液膜厚度的变化规律和界面波的演化特征。通过多尺度理论分析，建立考虑超疏水微结构影响的液膜时均流动数学模型，分析微结构局部流场特性及对液膜厚度的影响；在此基础上考虑液膜自由面滚波的影响，通过理论分析建立液膜自由面演化的理论模型，研究超疏水表面滚波演化特征和对液膜厚度的影响；通过高速摄像和PIV流场测量系统开展液膜流动演化的机理实验，研究超疏水表面和自由面综合影响下的液膜流动特性。理论研究和实验验证相结合揭示超疏水球面液膜流动机理，为使用超疏水材料降低雨天雷达天线罩上雨水膜厚度提供理论依据。

A fluid-mechanical theory for the fluid film considering the influences of superhydrophobic surface and roll wave is seldom addressed. The investigation can improve the understanding of fluid mechanism on the fluid film, and provide the evidence on the application of superhydrophobic surface in practical engineering..Present study intends to investigate the evolution of fluid film over a superhydrophobic sphere by theoretical analysis and model experiments. A mathematical model for an averaged flow with accounts for the micro-structure effect will be set up by homogenization method. The local velocity field and the effect of micro-structure on the film thickness will be analyzed. A theoretical model for the fluid film evolution will be presented further by considering the free surface effect. The evolution characteristics of roll wave will be analyzed. An experiment will be conducted for the flow filed based on the PIV system, which will provide benchmarks for the theoretical model. Meanwhile, the influence of free surface and surperhydrophobicity on the fluid film can be investigated. The systematic investigation by theory and experiment can reveal the flow mechanism of the fluid film over a superhydrophobic sphere, which is expected to provide an efficient method of calculating the film thickness on radome.