Numerical Analysis of Metal Transfer in GMAW
G. Wang*, P. G. Huang*, and Y. M. Zhang**
* Department of Mechanical Engineering, University of Kentucky
** Center for Robotics and Manufacturing Systems and Department of
Electrical and Computer Engineering, University of Kentucky
G. Wang*, P. G. Huang*, and Y. M. Zhang**
* Department of Mechanical Engineering, University of Kentucky
** Center for Robotics and Manufacturing Systems and Department of
Electrical and Computer Engineering, University of Kentucky
Abstract
The characteristics of metal transfer in gas metal arc welding (GMAW) are simulated by a new transient two-dimensional numerical model. Advanced CFD techniques used in this model include a two-step projection method for solving the incompressible fluid flow; a volume of fluid (VOF) method for capturing free surface; and a continuum surface force (CSF) model for calculating surface tension. The electromagnetic force due to the welding current is estimated by assuming several different kinds of current density distribution on the free surface of the drop. The simulations based on the assumption of Gaussian current density distribution show that the transition from globular to spray transfer mode occurs over a narrow current range and the size of detached drops is non-uniform in this transition zone. The analysis of the calculation results gives a better understanding of this physical procedure. Comparisons between calculated results and experimental results are presented. It is found that the results computed from the Gaussian assumption agree well with those observed in experiments.( 1.35 MB .doc ) ( AVI )