球形面喷涂成膜特性研究

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摘   要：针对球形面喷涂成膜气液两相流动耦合过程，利用欧拉-拉格朗日法建立球形面喷涂成膜模型，模型包括连续相模型、离散相模型和撞击黏附模型，并采用多面体网格和SIMPLE算法对其进行求解. 数值模拟结果表明：球形面喷涂喷雾流场形态与平面喷涂喷雾流场形态在扩散区基本相同，但在成膜区球形面喷雾流场气相速度更大、覆盖范围更广;喷雾流场中的大粒径液滴和中等粒径液滴是形成涂料液膜的主要来源;球形面喷涂涂膜轴向投影为椭圆的球面，平面喷涂涂膜为椭圆面，两者涂层厚度均沿椭圆径向方向递减;球形面喷涂涂层厚度比平面薄，涂膜分布范圍比平面小，涂料涂着率比平面低，但涂层均匀性比平面好;随着球形面直径增大，球形面喷涂涂膜覆盖范围逐渐扩大，涂层厚度增大，涂着率增大，涂层厚度均匀性增加. 喷涂实验验证了球形面喷涂成膜特性.

关键词：喷涂成膜;喷雾流场;两相流;计算流体力学

中图分类号：TG174.442;O35                 文献标志码：A

Research on Characteristics of Paint Deposition on Spherical Surface

CHEN Yan，HU Jun，ZHANG Gang，CHEN Wenzhuo，PAN Haiwei，LOU Bowen

（Department of Petroleum，Army Logistics University，Chongqing 401331，China）

Abstract：  In order to describe the two-phase coupling flow process of paint deposition on spherical surface， the Euler-Lagrange method was used to establish the model of paint deposition on spherical surface， including continuous phase model， discrete phase model as well as impinging and sticking model. Polyhedral mesh and SIMPLE algorithm were used to solve this model. According to the results of numerical simulation， the spray flow field of paint deposition on spherical surface and flat almost has the same form in the diffusion zone， but in the paint-deposition zone， the gas phase velocity and the coverage of the spray flow field on spherical surface are larger than those on flat. The main source for forming the paint film is large-diameter particles and medium-diameter particles in the spray flow field. The shape of paint films on the spherical surface is a spherical surface， of which the projection on axial direction is an oval， while it is an oval on flat， and the film thickness decreases along the elliptical radial direction. By comparison， the film thickness on spherical surface is thinner than that on flat， and the coverage of film distribution and the painting rate on spherical surface are smaller than those on flat. However， the uniformity of paint film on spherical surface is better than that on flat. As the diameter of spherical surface increases， the coverage of film distribution and the uniformity of film thickness increase，and the film thickness and the painting rate also increase. The characteristics of paint deposition on spherical surface were verified by experiments.

Key words： paint deposition;spray flow field;two phase flow;computational fluid dynamics

空气喷涂是一种借助喷涂工具，利用高压空气将涂料分散成均匀细小液滴，并将其附着到被喷工件表面的涂装技术[1]. 在空气喷涂作业过程中会遇