Abstract

Global surface pressure measurements have been carried out on a 7° half-angle circular cone/flare model at nominally zero angle of attack using pressure-sensitive paint (PSP). These experiments were conducted to illustrate the PSP technique’s usefulness and effectiveness at measuring the unsteady structures inherent to hypersonic shock-wave/boundary-layer interactions (SWBLI) on a global scale. Mean and fluctuating surface pressure was measured with a temperature-corrected, high-frequency-response (\(\approx 10\) kHz) anodized-aluminum pressure-sensitive paint (AA-PSP). This AA-PSP was made in-house to provide the high frequency response required. Methodologies for tracking the boundary-layer separation and reattachment shock feet in both time-averaged and instantaneous senses are provided and discussed. Excellent agreement is observed between the different metrics. In addition, spectral analyses were conducted on a global scale providing insights into the unsteady dynamics of the shock feet and structures under the separated shear layer. These spectral analyses identified a smooth, low-frequency bandwidth centered at \(\approx 500\) Hz, which is characteristic of the shock-foot oscillations. These experimental findings validate the usefulness of AA-PSP to provide global physical insights of unsteady SWBLI surface behavior in the hypersonic flow regime. Similar methodologies can be incorporated in future experiments to investigate complex and novel SWBLI.

Graphic abstract

中文翻译：

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高音速冲击波/边界层与压敏涂料的相互作用的整体测量

摘要

使用压敏涂料（PSP）在标称零攻角的7°半角圆锥/喇叭形模型上进行了整体表面压力测量。进行这些实验是为了说明PSP技术在全球范围内测量高超声速冲击波/边界层相互作用（SWBLI）固有的不稳定结构的有用性和有效性。使用温度校正的高频响应（\（\大约10 \）来测量平均和波动的表面压力 kHz）阳极氧化铝压敏涂料（AA-PSP）。这款AA-PSP是内部制造的，可提供所需的高频响应。提供并讨论了在时间平均和瞬时意义上跟踪边界层分离和重新附着的冲击脚的方法。在不同的指标之间观察到了极好的一致性。此外，在全球范围内进行了频谱分析，从而深入了解了分离的剪切层下的冲击脚和结构的非稳态动力。这些频谱分析确定了以\（\大约500 \）为中心的平滑低频带宽 Hz，这是电击脚振动的特征。这些实验结果证实了AA-PSP在高超声速流态下提供不稳定SWBLI表面行为的整体物理见解的有用性。可以在以后的实验中采用类似的方法来研究复杂而新颖的SWBLI。

图形摘要