ENTHALPY TECHNIQUE FOR SOLUTION OF STEFAN PROBLEMS: APPLICATION TO THE KEYHOLE PLASMA ARC WELDING PROCESS INVOLVING MOVING HEAT SOURCE

摘要

A computational methodology is carried out to predict the transient development of the weld pool and the temperature histories in the workpiece during plasma arc welding (PAW) of type AISI-304. One aim of this paper is the modelling of conduction heat transfer with phase change where the thermal conductivity and specific heat in the solid region are nonlinear functions of temperature. A stable numerical solution in a two dimensional fixed grid domain is demonstrated when an implicit time scheme, back substitution procedure is used to solve the governing equation. The influence of the different parameters such as, welding speed, keyhole diameter, thermal properties, distance between the nodes in the region of interest and the time steps on the welding quality and numerical consideration are studied.