Examination of Welding Nozzle Jet Flow at Cold Flow Conditions Available to Purchase

A fundamental study of welding nozzle flow under cold flow conditions is presented. The aim is to examine the shielding gas flow characteristics for several Gas Metal Arc Welding (GMAW) flow conditions. Experimental investigations and numerical modeling are used to predict the flow behaviour of the gas shielding the weld pool. Results are presented for generic GMAW nozzle configurations at typical welding situations under cold flow. Flow visualization and Particle Image Velocimetry (PIV) reveal the various flow characteristics that are crucial to optimization of weld pool protection by the shielding gas. Numerical modeling of the flow is performed at conditions similar to the PIV experiments using the k-ε turbulence model in a commercial CFD package. Numerical predictions of the mean velocities agree reasonably well with PIV experiments, particularly in the radial wall jet region of the flow field. However, the turbulent kinetic energy is greatly over-predicted due to the eddy-viscosity stress-strain approximation in the k-ε model.