The high enthalpy nozzle converts the high enthalpy stagnation gas into the hypervelocity free flow. The flow region of the high enthalpy nozzle consists of three parts: an equilibrium region upstream of the throat, a non-equilibrium region near the throat, and a frozen region downstream of the throat. Here we propose to consider the thermochemical non-equilibrium scale effects in the high enthalpy nozzle. By numerically solving axisymmetric compressible Navier-Stokes equations coupling with Park’s two-temperature model, the fully non-equilibrium solution is employed throughout the entire nozzle. Calculations are performed at different stagnation conditions with the different absolute scales and expansion ratio. The results of this study are twofold. Firstly, as the absolute scale and expansion ratio increase, the freezing position is delayed, and the flow approaches equilibrium. Secondly, the vibrational temperature and Mach number decrease with the increase in the nozzle scale and expansion ratio, while the speed of sound, static pressure, and translational temperature increase as the nozzle scale and expansion ratio increase.

中文翻译：

---

高焓喷嘴的热化学非平衡垢效应

高焓喷嘴将高焓停滞气体转换为超高速自由流动。高焓喷嘴的流动区域由三部分组成：在喉咙上游的平衡区域，在喉咙附近的非平衡区域和在喉咙下游的冷冻区域。在这里，我们建议考虑高焓喷嘴中的热化学非平衡垢效应。通过数值求解轴对称可压缩的Navier-Stokes方程，再结合Park的两个温度模型，在整个喷嘴中采用完全不平衡的解决方案。在不同的停滞条件下以不同的绝对比例和膨胀率进行计算。这项研究的结果是双重的。首先，随着绝对比例和膨胀比的增加，冻结位置被延迟，流量接近平衡。其次，振动温度和马赫数随喷嘴尺寸和膨胀比的增加而降低，而声速，静压和平移温度随喷嘴尺寸和膨胀比的增加而增加。