Heat Flow Characteristics of Segmented Laminar Plasma Torch Influenced by Interelectrode Structure Based on Numerical Simulation

To further enhance the jet characteristics of the laminar plasma torch, various anode, cathode, and arc chamber configurations have been proposed and investigated through both experimental and theoretical approaches. As a critical component, the interelectrode structure significantly influences not only the jet characteristics but also the operational lifespan of the plasma torch. Therefore, based on a custom-designed segmented laminar plasma torch, this study examines the effect of the interelectrode configuration on the thermal-flow characteristics using a self-developed 2-D simulation model, validated by experimental data. First, typical interelectrode structures employed in the custom torch were analyzed to identify an optimal design. A corresponding simulation model was then developed and verified using the in-house 2-D modeling framework. Subsequently, the influence of the interelectrode on the thermal-flow behavior of the plasma torch was systematically simulated and analyzed, leading to the development of predictive models for jet characteristics. The findings are summarized as follows: The simulated arc voltages agree well with experimental results, showing errors below 3%, which confirms the model’s effectiveness in simulating plasma jet flow behavior. The plasma flow within the torch can be divided into three regions: the arc initiation ring Region A, the interelectrode Region B, and the anode Region C. The interelectrode diameter has minimal influence on temperature and velocity distributions in Region A, whereas both axial temperature and velocity generally decrease with increasing interelectrode diameter in regions B and C. The pilot electrode diameter only affects the temperature and velocity distributions within its corresponding internal section, with a tendency for both to increase as the diameter decreases.