Wang Zhenqing, Tang Xiaojun, Lv Hongqing
College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China.
ScientificWorldJournal. 2014 Mar 6;2014:748504. doi: 10.1155/2014/748504. eCollection 2014.
The response of hypersonic boundary layer over a blunt wedge to freestream pulse acoustic disturbance was investigated. The stability characteristics of boundary layer for freestream pulse wave and continuous wave were analyzed comparatively. Results show that freestream pulse disturbance changes the thermal conductivity characteristics of boundary layer. For pulse wave, the number of main disturbance clusters decreases and the frequency band narrows along streamwise. There are competition and disturbance energy transfer among different modes in boundary layer. The dominant mode of boundary layer has an inhibitory action on other modes. Under continuous wave, the disturbance modes are mainly distributed near fundamental and harmonic frequencies, while under pulse wave, the disturbance modes are widely distributed in different modes. For both pulse and continuous waves, most of disturbance modes slide into a lower-growth or decay state in downstream, which is tending towards stability. The amplitude of disturbance modes in boundary layer under continuous wave is considerably larger than pulse wave. The growth rate for the former is also considerably larger than the later the disturbance modes with higher growth are mainly distributed near fundamental and harmonic frequencies for the former, while the disturbance modes are widely distributed in different frequencies for the latter.
研究了钝楔高超音速边界层对自由流脉冲声扰动的响应。比较分析了自由流脉冲波和连续波作用下边界层的稳定性特征。结果表明，自由流脉冲扰动改变了边界层的热传导特性。对于脉冲波，主要扰动簇的数量沿流向减少，频带变窄。边界层中不同模态之间存在竞争和扰动能量转移。边界层的主导模态对其他模态有抑制作用。在连续波作用下，扰动模态主要分布在基频和谐频附近，而在脉冲波作用下，扰动模态广泛分布于不同模态。对于脉冲波和连续波，大多数扰动模态在下游进入较低增长或衰减状态，趋于稳定。连续波作用下边界层中扰动模态的振幅远大于脉冲波。前者的增长率也远大于后者，前者中增长较高的扰动模态主要分布在基频和谐频附近，而后者的扰动模态广泛分布于不同频率。
