强激波阵面的非平衡结构研究

Research of nonequilibrium structure of strong shock front

利用测量强激波波后N2^＋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测量过程进行了探索，并利用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。测量和计算结果进行了对比。结果表明：N2^＋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7．65～7．85km／s、P1=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。

The vibrational temperature and electron number density behind strong shock waves were measured in shock tubes, and the results were compared with those of theoretical calculation. The vibrational temperature was derived by measuring the radiation of （0,0） and （1,2） bands of N2^＋ first negative system. According to the experimental results, the electronic energy of N2^＋ 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 （P1 = 1.33Pa, V, = 7.65 -7.85km/s） in a low density shock tube （ Ф0.8m）, the effective test time was only about 6.5μs, so the electron number densitiy could not reach the peak in such a short time. The agreement between measurement and calculation are good during the effective test region, which is about 10 times freestream mean-free-molecular path.