Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2018
Student: FATİH DEMİR
Supervisor: ABUZER ÖZSUNAR
Open Archive Collection: AVESIS Open Access Collection
Abstract:As a result of the literature investigated in this study, a non-transferred DC plasma torch is modeled. The plasma torch is modeled as three-dimensional and the flow is assumed to be turbulent and incompressible. Argon was used as working fluid. The solutions were done as time-independent (steady-state) and time-dependent (transient). In this study, the position of the anode arc root attachment was tried to be determined and the erosion of the anode wall was tried to be reduced. The effects of the current values defined by the cathode wall and the different volumetric flows of the gas on the plasma temperature, plasma velocity, plasma exit temperature and velocity, plasma electrical potential, anode arc root point temperature, anode arc root attachment and torch efficiency were investigated. ANSYS Fluent and Magnetohydrodynamic modules are used together to reveal the interaction between the electromagnetic field caused by the electric arc in the plasma torch and the gas flow. In order to investigate the effects of current and gas volumetric flow rate in the study, the current value was kept constant in one part of the analysis and the volumetric flow rate of the gas was changed. In the other part, the gas flow rate was kept constant. Additionally, the current and volumetric flow rate are kept constant in the solutions made for different output diameter and different anode wall length of the plasma torch. At the constant gas volumetric flow, plasma temperature, anode arc root attachment temperature and plasma velocity were increased with increasing the current. It has been observed that the anode arc root point moves towards the entrance of plasma torch with increasing current values. At constant current, it has been observed that there is no significant change in the plasma temperature and the anode arc root attachment temperature by increasing the gas flow rate. It has been seen that the plasma velocity increases with increasing gas flow rate. The anode arc root point moves towards the exit of plasma torch with increasing gas flow rate. It is seen that the the obtained results are consistent with the literature.