Abstract

The strong background radiation in high enthalpy hypersonic shock tunnels has posed severe challenges for measurement using luminescent coatings. We proposed a solution for reducing background radiation from time-resolved temperature-sensitive paint (TSP) measurement in a hypersonic flow with Ma = 6.5 and T₀ = 3525 K. The TSP was applied on an inlet ramp model, and the images were taken by a high-speed camera at 2 kHz under a modulated excitation. The strong background radiation led to a low signal-to-noise ratio and significant errors for the first half of the 130-ms test duration. Accordingly, three noise reduction methods were developed and evaluated based on temporal reconstruction, spatial reconstruction and robust principal component analysis (RPCA), respectively. The RPCA method showed the best performance that successfully recovered high-quality TSP data for a majority of test duration (t ≥ 40 ms).

Graphic abstract

中文翻译：

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高焓高超声速隧道中强背景辐射污染的温度敏感涂料测量的降噪

摘要

高焓高超音速冲击隧道中的强背景辐射对使用发光涂层的测量提出了严峻的挑战。我们提出了一种解决方案，用于减少在Ma  = 6.5和T ₀的高超声速流中时间分辨的热敏涂料（TSP）测量中的背景辐射 TSP = 3525K。将TSP应用于入口坡道模型，并在调制激励下以2 kHz的高速相机拍摄图像。在130毫秒的测试持续时间的前半段中，强烈的背景辐射导致信噪比低和明显的误差。因此，分别基于时间重构，空间重构和鲁棒主成分分析（RPCA），开发并评估了三种降噪方法。该方法RPCA表明，成功地恢复高质量TSP数据的多数的测试持续时间（最佳性能吨 ≥40毫秒）。

图形摘要