用电子束荧光技术研究高超声速边界层中的扰动现象

The investigation of perturbation phenomena in hypersonic bound ary layer with electronic beam fluorescence technique

利用电子束荧光技术对高超声速平板边界层中的扰动现象进行实验研究，实验在炮风洞中进行，自由流马赫数为7.8，单位长度雷诺数为3.5×107/m，测量了平均密度分布、脉动密度分布，并获得了湍流密度脉动的互相关分布和频谱分布。实验结果表明在过渡区中有序与随机现象并存。

The perturbation phenomena in hypersonic flat plate boundary layer are investigated wi th electronic beam fluorescence technique in a gun wind tunnel.Mach number of fr ee stream is about 7.8 and Reynolds number per unit length is 3.5×107/m.Avera ge density distribution and fluctuation desity distribution are measured.The cor relation distribution of turbulent density fluctuation and frequency spectrum di stribution is obtained.Our experimental results show that the phenomena are coex isted in order and at random in transition area.