Numerical analysis of arc in plasma arc welding

Three dimensions finite element mathematical model for the PAW arc was established by considering the effect of plasma gas and shielding gas. The temperature and velocity of the arc were simulated using ANSYS FEA software, as well as the distributions of arc pressure and current density at the anode surface. Compared with the TIG welding arc, the simulated results show that the temperature of the PAW arc is remarkably enhanced. The highest temperature is 30, 000K at a current of 150A.The other distinct character of the PAW arc is that the arc velocity and pressure is much higher. The PAW arc can be dealt in a laminar incompressible state judged by the Mach number and the ratio of effective viscosity and dynamic viscosity.