A NUMERICAL MODEL FOR ELECTROMAGNETIC FORCE OF ARC WELDING IN HIGH GRAVITY CONDITION

Gas Tungsten Arc welds onto the aluminum and nickel are investigated at varying levels of gravity (g) using A CFD scheme. Axisymmetric forms of continuity, Navier-stokes and energy equations are solved to find the flowfield, temperature distribution and welding pool shape in the work-piece. Having some analytical integral solutions related to Maxwell’s equations in an axis-symmetric system with Magneto-hydrodynamics (MHD) approximation, an accurate description of the electromagnetic force in the welding pool is considered. Comparison of the numerical results with the existing experimental data shows that in agreement with the experimental data the depth of the melting pool decreases as gravity increases but this trend is more markedly observed experimental data. In other word numerical simulations show deeper weld pool penetration compared with the existing results. A dimensional analysis justifies this due to the effect of Coriolis and centrifugal forces on the arc plasma flow which changes the arc pressure and shear stress over the work piece. The velocity in the melting pool increases at higher level of gravity and enhances convection.