The Influence of Rectangular Nozzle’s Aspect Ratio on the Thermodynamic Characteristics of Plasma Jet

Plasma wind tunnels are important facilities for conducting ground experiments on electromagnetic, force, and thermal aspects of aircraft. The study and analysis of the thermodynamic characteristics of wind tunnels are important prerequisites for conducting experiments. Compared to circular nozzles, rectangular nozzles, with their flattened structure, can generate a more uniform plasma layer within limited experimental spaces, resulting in boundary layer thickness closer to real flight conditions. This makes studying their thermodynamic characteristics crucial for plasma wind tunnel flow field experiments. This article conducted numerical simulations and experimental measurements on the total temperature and total pressure of two types of rectangular nozzles under subsonic conditions and analyzed the influence of rectangular nozzle structure on the thermodynamic characteristics of plasma jets. The results show that the maximum relative errors between the numerical and experimental results are 15.18% and 7.11%, respectively. Rectangular nozzles with higher aspect ratios exhibit higher total pressure and lower total temperature. These findings provide an important reference for improving the flow field quality of inductively coupled plasma (ICP) wind tunnels and designing nozzles.