Thermohydrodynamic characteristics of the cascaded arc plasma generator with a large ratio of radius and pipe length

Numerical analysis was performed on the laminar thermal plasma flow of a constricted cascaded arc plasma generator with a larger ratio of radius and pipe length compared to previously used arc plasma generators. The numerical results concerning plasma temperature and velocity were compared with the experimental data measured using the probes methods. The effects of the mass flow rate of the plasma gas and the supplied current on plasma temperature, velocity, and current at a cross section of the plasma torch are clarified. These effects on plasma temperature and current density are estimated to be small when using a numerical model employing a single flow and a single temperature without taking into account the effects of the collision and dispersion of plasma gas particles. Except for the large mass flow rate of plasma gas, the numerical results for the plasma velocity are almost identical in magnitude to the experimental data.