Droplet formation, detachment, and impingement on the molten pool in gas metal arc welding

A mathematical model is developed to describe the globular transfer in gas metal are welding (GMAW). This work is both theoretical and experimental. U sing the volume-of-fluid (VOF) method, the fluid-flow and heat-transfer phe nomena are dynamically studied during the following processes: droplet form ation and detachment, impingement of a droplet on a solid substrate, imping ement of multiple droplets on the molten pool, and solidification after the are extinguishes. A He-Ne laser, in conjunction with the shadow graphing t echnique, is used to observe the metal transfer processes. Theoretical pred ictions and experimental results are in close agreement, suggesting that th e theoretical treatment of the model is good.