Two-dimensional modeling concerning the effects of the boundary conditions along the cathode sheath-arc column interface on the characteristics of the dual-jet arc plasmas

The distributions of the temperatures and the current densityies along the cathode surface can affect the characteristics of the arc column in the numerical modeling of the arc plasmas. In order to study the influences of different boundary conditions on the arc column characteristics of the plasmas, a two-dimensional modeling on the features of the dual-jet arc plasmas with different boundary conditions for the current density, electron and heavy-particle temperatures along the cathode sheath-arc column interface are conducted based on a two-temperature hydrodynamic model. The modeling results are also compared with the experimental measurements to discuss the feasibility of the different boundary conditions. The calculationed results show that, with the constant arc current and constant geometrical dimensions of the plasma generator, the influence of the heavy-particle temperature distributions along the outer edge of the cathode sheath layer on the plasma characteristics in the arc column region is negligible; the boundary condition of the current density along the outer edge of the cathode sheath has an obvious effect on the flow patterns in the arc column region; meanwhile, the electron temperature distributions along the cathode sheath-arc column interface would influence the arc shapes, and the heat transfer and the plasma flow patterns in the arc column region significantly.