Simulation and validation of the effective power absorbed by a non-equilibrium plasma flow inside the medium-power inductively coupled plasma wind tunnel

A non-equilibrium magneto-hydrodynamic model coupled with a power absorption model was established to calculate the effective power absorbed by the plasma flow inside a 110 kW medium-power inductively coupled plasma wind tunnel. This magneto-hydrodynamic model takes into account the coupling of Navier-Stokes equations, electromagnetic field equations, five species and eight chemical reactions of nitrogen, and a four-temperature model. Moreover, the power absorption model not only considers the power loss from the power supply system but also the coupling efficiency between plasma and the inductive coils. First, the anode loss of an electronic tube and its oscillator circuit efficiency is calculated, respectively, to obtain the total power loss from a radio frequency power supply system. Second, a transformer circuit model of the inductively coupled plasma (ICP) is established to calculate the coupling efficiency between the coil and plasma. Third, the effective power absorbed by the plasma flow and the pathways of the power losses of a medium-power ICP wind tunnel are obtained and discussed. Finally, the flow-field properties of the plasma flow, which are simulated by solving the Navier-Stokes equations coupled with the power absorption model, are obtained and analyzed. Furthermore, the simulated results are compared with corresponding experimental data, and they agree well with each other. It is found that the power loss of the electron tube oscillator accounts for 40%. It is the most dominant part of the total power loss. The effective power absorbed by a plasma flow is about 33.6% for the 110-kW inductively coupled plasma wind tunnel.