(336b) Simulation and Experimental Validation of a Lagrangian Multiphase Model for Rotary Bell Cup Atomization

Rotary bell cup atomization is the main approach in auto industry to apply coatings on car bodies. The spray formed from rotary bell cup are electrically charged and directed towards the spraying target by shaping air and shaping electric field. The droplet transfer process will have great impact on transfer efficiency and the final appearance of the coating. Simulation of the droplet transferring process allows us to develop a better understanding towards the complex flow field in rotary atomization, as well as providing a virtual manufacturing tool for reducing design cost and cycle. In this work, we developed multiphase Computational Fluid Dynamics(CFD) approach to simulate the droplet transfer process in rotary atomization. Lagrangian multiphase model is used to model the discrete droplets and is two way coupled to the continuous phase. Paint layer thickness and droplet characteristics are discussed, and the results are compared against experimental data from high speed imaging. Furthermore, secondary particle interaction models and their impact on the simulation results are also investigated.