Numerical modeling of the electrostatic painting process

静电涂装和粉末涂装是在汽车工业中广泛使用的成熟的工业工艺。然而，在所有条件下实现最大转移效率方面存在一些挑战。此外，质量控制问题，如涂料不均匀，粉末涂料的反电晕等，比他们应该发生的更多。解决这些问题的一般方法是根据经验改变操作参数。然而，由于涉及的变量很多，这往往是无效的。以前对这一过程进行建模的努力存在严重缺陷，因为它们的假设受到限制，并且仅限于静电力或气动力。该项目的目标是通过使用现代数值建模技术，通过将静电和流体流动现象相结合来对过程进行建模，从而提高技术水平。使用该模型，然后可以应用多变量优化技术来确定最佳操作条件。该模型的一个关键部分是包含了喷雾云内的颗粒尺寸分布(以及由此产生的电荷分布)。申请人最近证明，这一因素在优化转移效率方面发挥了关键作用。

Electrostatic painting and powder coating are well established industrial processes in wide use in the automobile industry. However a number of challenges exist in achieving maximum transfer efficiencies under all conditions. Furthermore quality control issues such as non-uniform paint coating, back corona in powder coating etc occur more often than they should. The normal approach to resolve these problems is to vary the operating parameters empirically. However because of the large number of variables involved, this often is ineffective. Prior efforts to model the process have had serious shortcomings because they have been limited in their assumptions and restricted to either electrostatic or aerodynamic forces. The goal of this project is to advance the state of the art by modeling the process through combining both electrostatic and fluid flow phenomena using modern numerical modeling techniques. Using this model, multi-variable optimization techniques may then be applied to determine the best operating conditions. A crucial part of the model is the inclusion of the particle size distribution (and resulting electric charge distribution) within the spray cloud. This factor has recently been demonstrated by the applicants to play a crucial role in optimizing transfer efficiency.