Numerical Simulation On The High Frequency Discharge Of Inductively Coupled Plasma Wind Tunnel

In order to study the re-entry aircraft thermal protection materials and carry out the aerodynamic performance test of the aircraft,in recent years,various countries and different levels of plasma wind tunnel exp erimental equipment have been established,such as arc heating wind tunnel,shock wave tunnel and inductively coupled plasma wind tunnel(also known as high frequency inductive plasma wind tunnel or RF plasma wind tunnel).Because the inductively coupled plasma has many advantages,such as no electrode pollution,uniform temperature and large arc area,it can provide pure heat source,and the working medium is not limited.Thus,it has great application prospects in aerospace,metallurgy,chemical and other industrial fields.On the basis of the inductively coupled plasma source,it has very important application prospects.It is very necessary to study the inductively coupled plasma discharge characteristics in detail.This paper mainly analyzes the effect of different discharge frequencies on the plasma characteristics of a 10 kW argon inductively coupled plasma wind tunnel under typical operating conditions of p=4000 Pa.The discharge characteristics of nonequilibrium inductively coupled plasma under different operating parameters(discharge frequency,working pressure,coil power and mass flow rate)are analyzed.These results could provide theoretical guidance and basic theoretical data for the optimal design and industrial applications of inductively coupled plasma wind tunnel.In this paper,a two-dimensional axisymmetric geometric model was established for modeling the discharge process of cylindrical inductively coupled plasma.In the numerical calculation,we used the fluid mechanics model(MHD)to simulate the inductively coupled plasma under the equilibrium and the nonequilibrium states' and to obtain different discharge properties of the ICP flow.Furthermore the numerical results were compared with the experimental result.It is concluded that the flow field results of the inductively coupled plasma obtained by using the nonequilibrium model were more consistent with the experimental results,and it was also more reasonable in theory,Next,we analyzed the effects of different operating parameters on the nonequilibrium inductively coupled plasma discharge.The calculation results showed that the maximum electron number density in the plasma torch increased with the increase of working pressure and coil power,but decreased with the increase of discharge frequency and inlet mass flow rate.The maximum electron temperature increased with the increase of coil power,but decreased with the increase of discharge frequency,working pressure and inlet mass flow rate.The maximum gas velocity in the plasma torch increased with the increase of coil power and inlet mass flow rate,but decreases with the increase of discharge frequency and working pressure.In addition,it was also found that the maximum average temperature in the plasma torch increased with the increase of working pressure and coil power,but decreased with the increase of discharge frequency and inlet mass flow rate.