Analysis of droplet impingement of different atomizers used in spray coating processes

This paper presents numerical studies on spray painting processes using three different atomizers, i.e., a high-speed rotary bell atomizer, an airless gun and a pneumatic air spray gun. A commercial CFD code was applied using an Euler-Lagrangian approach for two phase flow calculations. Special attention was paid to the droplet impingement process on the substrate. Orthogonal impact velocities and size distributions of the droplets depositing on substrates were analyzed in detail. The obtained simulation results show substantial differences of the impacting droplet characteristics of these three atomizers, which will have significant influences on the properties of the forming paint films.