The accuracy and sensitivity of plasma generation predicted by several different chemical kinetics models is investigated in the context of weakly ionized hypersonic flowfields around the Radio Attenuation Measurement (RAM-C) vehicle. A computational fluid dynamics analysis is used to examine 13 independent trajectory points along the RAM-C II flight, and an assessment of the chemistry models is made by comparing results to available flight measurements. The limitations of making such comparisons with the raw flight data are established in detail, including the inherent shortcomings associated with interpolating the flight data to assess a single trajectory point. Two separate geometries are evaluated in this study, as the initial RAM-C geometry was altered during flight after its nose cap was pyrotechnically ejected. The blunter post-ejection geometry generates more electrons in the stagnation region. In general, good agreement is found between each chemistry model and flight data from both the electrostatic probe and reflectometer stations above 56 km. An expected sizable gap exists between the simulations and reflectometer data at lower altitudes. The impact of forward reaction rates, equilibrium constants, and number of species varies considerably based on altitude, velocity, and position along the body.

在无线电衰减测量 (RAM-C) 车辆周围的弱电离高超声速流场的背景下，研究了由几种不同化学动力学模型预测的等离子体生成的准确性和灵敏度。计算流体动力学分析用于检查沿 RAM-C II 飞行的 13 个独立轨迹点，并通过将结果与可用飞行测量值进行比较来评估化学模型。详细确定了与原始飞行数据进行此类比较的局限性，包括与插入飞行数据以评估单个轨迹点相关的固有缺陷。在这项研究中评估了两种不同的几何形状，因为在其鼻盖被烟火弹射后，初始 RAM-C 几何形状在飞行过程中发生了变化。较钝的后喷射几何形状在停滞区产生更多的电子。一般而言，每个化学模型与来自 56 公里以上静电探针和反射仪站的飞行数据之间存在良好的一致性。在较低海拔的模拟和反射计数据之间存在预期的相当大的差距。正向反应速率、平衡常数和物种数量的影响因高度、速度和沿身体的位置而异。