强激波阵面的非平衡特性研究

利用测量强激波波后N_2~+第一负系(0,0)带和(1,2)带的辐射,对强激波后振动温度历程的进行了测量;利用Langmuir探针技术,在低密度激波管中对强激波后电子数密度历程进行了测量;在弹道靶中进行了激波脱体距离的测量研究.测量和计算结果进行了对比,结果表明:N_2~+B~2∑_u~+态的激发比振动能的激发更快:实验测得的振动温度有明显的周期性振荡;在激波速度7.65km/s～7.85km/s、p_1=1.33Pa、实验段内径0.8m下,实验有效时间只有约6.5μs,实验中的电子数密度不能达到峰值,在约10倍波前自由程的实验有效区域内,电子数密度的测量值与计算值吻合很好.激波脱体距离的测量误差约为5%,是目前国内精度最高的结果.

The research of nonequilibrium characteristics of strong shock front

The vibrational temperature and electron number density behind strong shock waves were measured in shock tubes, and the shock stand - off distance was measured in a ballistic range. The results were compared with those of theoretical calculations. The vibrational temperature was derived by measuring the radiation of (0,0) and ( 1,2) bands of N_2~+ first negative system. According to the experimental results, the electronic energy of N_2~+ can be excited faster than its vibrational energy, and there are periodic fluctuations in the measured vibrational temperature. In the measurement of electron number densitiy behind strong shock waves (P_1 =0. 01mmHg, V_s =7.65～7.85km/s) in could not reach the peak in such a short time. The agreement between measurement and calculation are good during the effective test region, which length is about 10 times of freestream mean - free - molecular path. The resolution of shock stand - off distance measurement is 5%, which is the best in China at present.