Abstract Nitric oxide planar laser-induced fluorescence was performed to measure the wall-normal distribution of static temperature through a hypersonic boundary layer. A 10-degree half-angle wedge model was oriented at a 5-degree angle of attack in the NASA Langley 31-in Mach 10 facility, resulting in a 5-degree flow turning angle and an edge Mach number of 7.6. Nitric oxide was seeded through a spanwise slot into the boundary layer upstream of the imaging region and was excited with a pulsed ultraviolet planar laser sheet. The laser was spectrally scanned across six fluorescence transitions in the (0, 0) band of the $$A^2\Sigma ^+$$ A 2 Σ + – $$X^2 \Pi $$ X 2 Π system. Eighteen thermometry methods were assessed through comparison to predictions of the temperature field from computational fluid dynamics simulations. The effect of spectral resolution and laser linewidth on measurement uncertainty was also investigated. The most accurate technique was spectral peak thermometry, which achieved an accuracy of ± 31.6 K ( $$12.6\%$$ 12.6 % error relative to CFD temperature). The spectral peak thermometry technique required a minimum spectral resolution between 0.074 and 0.102 $$ {\mathrm {cm}}^{-1} $$ cm - 1 and a maximum laser linewidth of 0.49 $$ {\mathrm {cm}}^{-1} $$ cm - 1 to extract meaningful temperature information from the spectra. Graphic abstract

中文翻译：

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一氧化氮激光诱导荧光测温技术在高超声速边界层中的评价

摘要 一氧化氮平面激光诱导荧光通过高超声速边界层测量静态温度的壁面正态分布。10 度半角楔形模型在 NASA 兰利 31 英寸 10 马赫设施中以 5 度攻角定向，导致 5 度流转向角和 7.6 的边缘马赫数。一氧化氮通过展向槽进入成像区域上游的边界层，并用脉冲紫外平面激光片激发。在 $$A^2\Sigma ^+$$ A 2 Σ + – $$X^2 \Pi $$ X 2 Π 系统的 (0, 0) 带中的六个荧光跃迁中对激光进行光谱扫描。通过与计算流体动力学模拟对温度场的预测进行比较，对 18 种测温方法进行了评估。还研究了光谱分辨率和激光线宽对测量不确定度的影响。最准确的技术是光谱峰值温度测定法，其精度为 ± 31.6 K（相对于 CFD 温度的误差为 12.6%\%$12.6%）。光谱峰值测温技术需要 0.074 和 0.102 $$ {\mathrm {cm}}^{-1} $$ cm - 1 之间的最小光谱分辨率和 0.49 $$ {\mathrm {cm}}^ 的最大激光线宽{-1} $$ cm - 1 从光谱中提取有意义的温度信息。图形摘要 光谱峰值测温技术需要 0.074 和 0.102 $$ {\mathrm {cm}}^{-1} $$ cm - 1 之间的最小光谱分辨率和 0.49 $$ {\mathrm {cm}}^ 的最大激光线宽{-1} $$ cm - 1 从光谱中提取有意义的温度信息。图形摘要 光谱峰值测温技术需要 0.074 和 0.102 $$ {\mathrm {cm}}^{-1} $$ cm - 1 之间的最小光谱分辨率和 0.49 $$ {\mathrm {cm}}^ 的最大激光线宽{-1} $$ cm - 1 从光谱中提取有意义的温度信息。图形摘要