Computational approach or numerical simulation is a trend in recent manufacturing technology, in the present study a computational approach is made for a pulse type GTAW to analyze the heat transfer and mass flow behavior using FEA software ANSYS 19.0. Transient thermal simulations are carried at three different heat inputs in the form of voltage and currents with the welding speed of 70mm/min. The heat source profiles are obtained with the different heat inputs from experimental investigations. The same heat source profiles are modeled using the Solid EDGE software and called in the ICEM CFD to generate grids with unstructured tetrahedral mesh and grids are also made for the workpiece by modelling for a dimension of 150mm × 100mm having 6mm thickness same as the experimental workpiece. The generated Finite element model is called in ANSYS Workbench for transient thermal simulations to obtain the temperature distributions and the heat source models are also called in ANSYS Fluent for velocity field. The heat source models selected and the temperature field obtained from the computational numerical simulations are in good agreement with the experimental results indicating validation of the simulation process made.