Abstract

The influence of thermal nonequilibrium on the laminar–turbulent transition is studied with the use of the \(\mathrm{e}^N\)-method for two widespread flow regimes in a supersonic boundary layer at the Mach number \(\textrm{M}=4.5\). The set of the actual frequencies of spatial disturbances is determined on the basis of the neutral curves for temporal disturbances. Families of the curves of \(N\)-factors are calculated for selected frequencies. Then, based on the envelopes of these curves, the transition Reynolds number \(\mbox{Re}_{\delta T}\) for a given transition factor \(N_T\) is determined. The calculations show that the transition region in the case with \(N_T=8\) and vibrational excitation level below the dissociation limit is located 12–14% downstream as compared to the transition region in a perfect gas.

中文翻译：

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气体的振动激发对平板上层流-湍流过渡区位置的影响

摘要

在层流紊流过渡热不平衡的影响进行了研究与使用的\（\ mathrm {E} ^ N \）在马赫数-method两个广泛流动方式在超音速边界层\（\ {TEXTRM M} = 4.5 \）。空间干扰实际频率的集合是根据时间干扰的中性曲线确定的。为选定的频率计算\（N \）-因子曲线的族。然后，基于这些曲线的包络，确定给定过渡因子\（N_T \）的过渡雷诺数\（\ mbox {Re} _ {\ delta T} \）。计算表明\（N_T = 8 \）的情况下的过渡区域 与理想气体中的过渡区域相比，低于解离极限的振动激发水平位于下游12–14％。