超疏水表面过冷水滴碰撞特性及动态结冰延迟机理研究

由于过冷水滴的撞击和沉积，飞机等装备表面容易发生结冰现象，严重影响运行效率和安全。超疏水表面因其对水的非润湿性，在防结冰领域具有重要的应用前景，但是目前过冷水滴碰撞超疏水表面的动力学特性及动态防结冰机理尚不明确。因此，本项目研究低温超疏水表面过冷水滴碰撞动力学行为，建立水滴与表面接触时间的理论模型，揭示固液接触时间的变化规律；研究超疏水表面过冷水滴结冰的热力学机制，结合水滴碰撞动力学特征，建立针对碰撞过程的动态结冰延迟时间预测模型；探究过冷水滴碰撞结冰的临界温度和临界韦伯数及其影响因素，对比分析固液接触时间和结冰延迟时间，确立碰撞结冰发生的临界准则。研究成果对于完善超疏水表面防结冰理论，推动装备表面防结冰性能的提升等具有重要的学术和工程意义。

Due to the impact and deposition of supercooled water droplets, surfaces of outdoor equipment such as aircrafts are prone to icing, which seriously affects the operating efficiency and safety. Superhydrophobic surfaces have important application prospects in the field of anti-icing, owing to their non-wetting properties to water. However, the dynamic characteristics and anti-icing mechanism of supercooled water droplets impacting superhydrophobic surfaces are still unclear. Therefore, the impact behavior of supercooled water droplets on cold superhydrophobic surfaces is studied, to establish a theoretical model of the contact time between droplets and surfaces, and further reveal the variation law of the solid-liquid contact time. Thermodynamic mechanism of supercooled water droplets freezing on superhydrophobic surfaces is analyzed, to propose a predictive model of the dynamic icing delay time, combining the impact dynamic characteristics. The critical temperature and Weber number for the icing of supercooled water droplets during impact and their influencing factors are explored. The critical criterion for the occurrence of impact icing is established, by comparing the contact time and the icing delay time. This research provides academic and engineering significance for developing the anti-icing theory of superhydrophobic surfaces and also improving the anti-icing performance of equipment surfaces.