Analysis of gas flow characteristics in nitrogen/hydrogen mixture arcjet

Modeling study is conducted to investigate the characteristics of gas flow in nitrogen/hydrogen mixture arcjet. According to the characteristics of the gas flow in the arcjet, the definition methods of the thermal boundary layer and the flow boundary layer in the arcjet are determined. The energy conversion process between main stream and boundary layer is discussed. The results show that the arc thermal energy is mainly converted into the gas thermal energy in the main stream of the constrictor, and the gas enthalpy is promoted. In the arc attachment region, the arc heating raises the enthalpy and kinetic energy of gas in boundary layer. Further study shows that reduction of constrictor length and increase of working current will improve the contribution of the main stream thrust to the total thrust, so as to improve the performance of the arcjet.