Numerical analysis of the effect of arc spray gun configuration parameters on the external gas flow

The objective of present study is to investigate the effect of different gun configuration parameters on the external gas flow by using a CFD model, and to optimize the design of an arc spray gun based on the modeling results. A converging nozzle and a converging/diverging nozzle for arc spraying were compared by calculating their flow distributions using a two-dimensional (2D) axially symmetrical model. Other parameters such as location of the intersection position and angle between the two wires were also analyzed in a three-dimensional (3D) model. The results show that the converging/diverging nozzle is more favorable for droplet atomization, moving the intersection position from the nozzle outside to the nozzle exit and using a moderate intersection angle are better for improving the flow dynamics properties. Consequently, an innovative design to upgrade the original HAS-01 type gun was put forward, and the modified design was experimentally compared with the original one by measuring the in-flight droplet size and velocity.