Akademik Veri Yönetim Sistemi
JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, cilt.33, ss.361-369, 2018 (SCI-Expanded)
Thermal plasma processes, the electric heating produced by the arc causes the gas to reach very high temperatures (e.g. > 10000 K), have proven their technological advantage in a wide variety of fields of industry. Non-transferred arc torches are typically used in applications that rely on the formation of a plasma jet with moderate to very high velocity and high temperature processing medium, such as plasma spraying and powder synthesis. Most DC arc torches have three main components: The cathode, the plasma forming gas injection stage, and the anode. In this study, argon DC non-transferred arc plasma torch geometry was designed. The plasma formation in the designed torch was simulated by a computational fluid dynamics (CFD) approach and parametric analysis was performed. Plasma torch was modelled three dimensional and the plasma flow was considered as steady, turbulent and incompressible. ANSYS Fluent and MHD modules were used together to solve the interaction between the electromagnetic field and the gas flow in the torch. Current density and gas mass flow rate were the parameters to investigate their effects on the plasma temperature and velocity at the torch exit. It was observed that there is a tendency for increase of temperature at the exit of the torch with increasing current and mass flow rate, but there is no monotonic increase. In addition, temperature and velocity profiles at the torch exit are not symmetrical in radial distance because of the the arc root attachment point on the anode wall surface.