An improved simulation of heat transfer and fluid flow in plasma arc welding with modified heat source model

► Heat transfer and fluid flow in plasma arc welding are simulated and validated. ► A combined effective heat source model is proposed. ► Both heating and key-holing effects of the plasma arc are described in the model. ► Fluid flow shows contribution to the formation of hump in the weld-fusion line. ► Optimal process parameters could be obtained by using our model.