Options
2002
Conference Paper
Titel
Simulation of the spray coating process using a pneumatic atomizer
Abstract
The spray behaviour of a co-axial jet type pneumatic atomizer used in the painting industry has been experimentally investigated and numerically modelled. In contrast to previous work, the commercial FLUENT program was applied using the EULER-Lagrangian approach. The programm was extended to calculate the film thickness from the local mass flux on the workpiece surface. The quality of the simulation was verified through comparisons of calculated and measured film thickness distributions on the work piece. Two major results could be obtained: Firstly, it was found that the complete air flow field between the nozzle and the target can be calculated applying the known air inlet conditions directly at the atomizer. Hence, the effect of variations of the air flow rates on the flow field can be determined without additional experimental efforts. Secondly, the initial droplet conditions necessary for the simulations (size distribution, velocity and flux) can be taken very close to the nozzle. In this way, also the two-way coupling process between droplets and air flow altering the spray cone shape may be considered. The resulting film thickness distribution calculated with practically relevant air and paint flow parameters corresponds in its main features nicely to the experimental result.