复杂形面空气喷涂涂料成膜机理及规律研究

Great many complex surfaces with variable curvature radius, variable normal line and/or large curvature etc. exist in industrial products with stealth fighters as their typical example. These tremendously affect the spray flow field and paint film of air spray painting. Trajectory planning of painting robot, film thickness calculation and coating thickness control thus become difficult problems when robot painting complex surfaces. The project divides the process of air spray painting into atomization, spray forming, and impinging sub-processes.The paint deposition model including an spray forming model with atomization result as its initial condition, and an impinging model is established. Euler-Euler model is adopted to model spray forming instead of Euler-Lagrange model because of its disadvateges. The impinging model is established by integrating the paint flux which satisfies adhering conditions for paint droplets. Euler-Euler model and local remeshing model of dynamic meshing method is proposed to solve film thickness calculation problem for the moving air spray gun. Through calculation of the paint deposition model and experiments, the research studies the characterization and causes of paint deposition on planes, the influence of complex surfaces on paint deposition and the influence of spraying parameters on paint deposition of complex surfaces. The project is aimed at revealing the paint deposition mechanism and law of air spray painting on complex surfaces, laying a theoretical and technical foundation on trajectory planning and film thickness calculation for robot painting complex surfaces.

以隐身战机为典型的许多工业产品，具有大量以变曲率、变法线和（或）大曲率等为特性的复杂形面，这些形面对空气喷涂的喷雾流场和涂膜影响极大，导致机器人喷涂的轨迹规划、涂膜厚度计算和涂层厚度控制的难题。本课题将空气喷涂成膜过程分解为雾化过程、喷雾过程和撞击粘附过程。建立的成膜模型包括喷雾流场模型和撞击粘附模型，雾化结果作为初始条件。针对欧拉-拉格朗日模型的局限性，提出采用欧拉-欧拉模型建立喷雾流场模型。对满足涂料微粒粘附条件的涂料流量进行积分，建立非完全沉积的撞击粘附模型。提出采用欧拉-欧拉模型结合动网格法的局部重构模型，解决动态喷涂的涂膜厚度计算难题。通过求解成膜模型结合实验，研究平面喷涂成膜表征及成因、复杂形面对空气喷涂成膜的影响和喷涂参数对复杂形面成膜的影响。研究旨在揭示空气喷涂复杂形面成膜机理和规律，为机器人喷涂复杂形面轨迹规划和涂层厚度计算奠定理论和技术基础。

以隐身战机为典型的许多工业产品，具有大量以变曲率、变法线和（或）大曲率等为特性的复杂形面，这些形面对空气喷涂的喷雾流场和涂膜影响极大，导致机器人喷涂的轨迹规划、涂膜厚度计算和涂层厚度控制的难题。本课题基于欧拉—欧拉法建立了由两相流喷雾流场模型和碰撞粘附模型构成的喷涂成膜模型，分别描述喷雾流场中气液两相流动和液相颗粒撞击壁面并沉积形成涂膜的过程。此外还建立了基于欧拉—拉格朗日法的喷涂成膜模型进行辅助研究。分别采用动网格法和滑移网格法，实现了动态喷涂的涂膜厚度计算。得到并分析了平面喷涂过程的喷雾流场和涂膜厚度分布，从液相颗粒对气相的影响、液相颗粒分布规律以及涂膜厚度分布规律等方面研究了平面喷涂成膜表征及成因。对圆弧面、球形面和锥形面等典型曲面的静态喷涂和动态喷涂过程进行数值求解，得到并分析了不同方式喷涂各种曲面的喷雾流场特性及涂膜厚度分布变化规律，揭示了复杂形面特性对空气喷涂成膜的影响。针对扇面压力、雾化压力、喷涂距离以及喷枪喷扫速率等喷涂参数，阐释了喷涂参数对复杂形面成膜的影响。研究揭示了空气喷涂复杂形面成膜机理和规律，为机器人喷涂复杂形面轨迹规划和涂层厚度计算奠定理论和技术基础，并将促进喷涂机器人在机械、汽车、船舶、家具、家电、航空等行业制造工程的进一步应用。