壁温对隔离段激波串振荡的影响

Effects of wall temperature on pseudo-shock oscillations in isolator

为了探索存在换热条件下超燃冲压发动机隔离段内部的复杂流动机理,采用2阶精度的非定常数值模拟程序研究了壁温对隔离段内部激波串振荡特性的影响。结果表明:压力振荡曲线与激波串前缘位置之间存在紧密关系。此外,随着壁温升高,隔离段壁面压力振荡的频率减小、振幅增加。研究还发现,隔离段压力振荡标准差最大值位于激波串前缘激波及其与上下壁面边界层相互作的位置,而湍动能最大值则分布在分离区后侧剪切层区域内。

To explore the complex flow mechanism in the scramjet isolator under differ- ent wall heat transfer, the effects of wall temperatures on the oscillation characteristics of pseudo-shock in the scramjet isolator were investigated with a two-order accuracy unsteady computational fluid dynamics code. The numerical results show that there is a close relationship between the wall pressure histories and the maximum upstream and downstream loca- tions of the shock-train leading-edge. Moreover, it shows that the fluctuating pressure amplitudes increase and frequencies decrease with the wall temperature. The maximum value of wall pressure standard deviation occurs at the place where the shock-train leading-edge shocks/boundary layer interact. However, the maximum values of kinetic energy are mainly in the shear layer region of the separation bubble.