Numerical simulation of the electrostatic powder coating process with a corona spray gun

In this paper the electrostatic powder coating process was numerically investigated using an extended commercial CFD code. The fully 3-dimensional turbulent flow was calculated. Based on the Langrangian approach the trajectories of the powder particles were modelled considering electric and aerodynamic forces. In calculation of the particle transportation both particle size distribution and particle charge distribution obtained through experiments have been applied. The models account for the space charge effect of the charged particles and the turbulence dispersion on the particle trajectories. It was found that the space charge plays an important role for the final spray pattern shape, also increasing the transfer efficiency. The numerical results, such as velocity profiles, static film thickness as well as dynamic film thickness on the target were compared with the experiment. Experimental and numerical results are in good agreement