含表面活性剂的液滴碰撞柔性粗糙叶片的实验与机理研究

At present, the chemical pesticide is the main tool to control the agriculture and forest disease and pest, however, it has not been well known whether the droplets of chemical pesticide can be good adhesion to the leaf surface. Therefore, the pesticide input is high and target effect is poor. In the proposed project, experiment, theoretical analysis and numerical simulation are combined to study droplet dynamics of surfactant solution droplets impact on flexible rough leaves. Considering flow (droplet) - solid (flexible leaves), physical (rough surface) - chemical (surfactant) together, the multiple-relaxation-time Lattice Boltzmann multiphase flow model is established and numerical simulation is carried out. It is explored that the interface evolution and contact angle variation change with the different parameters, so as to find the effect of droplet dynamic with surface tension, the capillary and viscoelasticity of cantilever beam, and reveal the wettability of surfactant solution droplets impact on flexible rough leaves. The optimal relationship between leaf surface of different plants and pesticide application parameters will be explored, providing theoretical basis and technical support for precise application of pesticides. The results have important research value and practical significance for improving the pesticide efficiency, reducing the pollution, protecting the ecological environment and realizing the sustainable development of agriculture and forestry.

目前用于农林业病虫害防治的农药液滴不能很好的粘附到靶标叶片表面上，导致农药投入量高，靶标针对性差。针对该现状，本项目结合实验、理论分析和数值模拟等手段对含表面活性剂液滴碰撞柔性粗糙叶片的动力学行为展开研究，拟建立流（液滴）-固（柔性叶片）、物理（粗糙表面）-化学（活性剂）耦合的多松弛格子Boltzmann多相流模型并进行数值模拟，深入系统的研究与探析参数变化时液滴的界面演变及接触角变化规律，重点阐明液滴表面张力、表面毛细作用和悬臂梁粘弹性对液滴动力学行为的影响，揭示含表面活性剂的农药液滴在柔性粗糙叶片上的润湿机理，探寻不同植物种类的叶片表面特征与施药参数的最佳匹配关系，为精准精量施药提供理论依据和技术支持。研究结果不仅对农药液滴动力学理论有科学的意义，对提高农药利用率、减少污染、降低用药剂量、保护生态环境和实现农林业可持续发展具有重要的研究价值和现实意义。

本项目以提高农药使用率，降低化学防治中的农药使用剂量为背景，结合实验、理论分析和数值模拟揭示含表面活性剂的农药液滴碰撞柔性粗糙叶片的作用机理。系统开展了不同表面活性剂种类、浓度、碰撞速度、液滴大小、叶片表面形貌、倾角、叶柄弹性模量等参数下的液滴碰撞实验研究。建立考虑流（液滴）-固（柔性叶片）、物理（粗糙表面）-化学（活性剂）耦合的多松弛格子 Boltzmann 多相流模型，探析了含表面活性剂液滴在柔性基底上的界面演变及接触角变化规律，重点阐明了液滴表面张力、表面毛细作用和悬臂梁粘弹性对液滴弹跳、铺展润湿等动力学行为的影响，揭示含表面活性剂的液滴在柔性粗糙叶片上的润湿机理。研究结果不仅对农药液滴动力学理论有科学的意义，对提高农药利用率、减少污染、降低用药剂量、保护生态环境和实现农林业可持续发展具有重要的研究价值和现实意义。