中文摘要：

感受性的目的是调查外部骚乱由产生不稳定的波浪的机制。在极超音速的边界层，一个新感受性过程被揭示，它是通过非线性的相互作用的快、慢的声学能近使第二个模式激动第二个模式降低分支。尽管，他们能产生和频率骚乱非线性的相互作用，它能使第二个模式激动。这个感受性过程被非线性的相互作用和边界层的 nonparallel 性质产生。感受性系数对和频率骚乱和降低分支的秒模式之间的 wavenumber 差别敏感。当 wavenumber 差别是零时，感受性系数是最大的。感受性系数随 wavenumber 差别的增加减少。和频率骚乱的进化在开始线性地成长，这也被发现。它显示和频率骚乱产生的强迫的学期与第二个模式共振。

英文摘要：

The objective of receptivity is to investigate the mechanisms by which external disturbances generate unsta- ble waves. In hypersonic boundary layers, a new receptivity process is revealed, which is that fast and slow acoustics through nonlinear interaction can excite the second mode near the lower-branch of the second mode. They can generate a sum-frequency disturbance though nonlinear interaction, which can excite the second mode. This receptivity process is generated by the nonlinear interaction and the nonparal- lel nature of the boundary layer. The receptivity coefficient is sensitive to the wavenumber difference between the sumfrequency disturbance and the lower-branch second mode. When the wavenumber difference is zero, the receptivity coefficient is maximum. The receptivity coefficient decreases with the increase of the wavenumber difference. It is also found that the evolution of the sum-frequency disturbance grows linearly in the beginning. It indicates that the forced term generated by the sum-frequency disturbance resonates with the second mode.