Leonov Boris S, Moran Ashley N, North Simon W, Miles Richard B
Opt Lett. 2024 Feb 1;49(3):426-429. doi: 10.1364/OL.503786.
This Letter describes, to the best of our knowledge, a new approach to flow tagging, nitric oxide (NO) Ionization Induced Flow Tagging and Imaging (NiiFTI), and presents the first experimental demonstration for single-shot velocimetry in a near Mach 6 hypersonic flow at 250 kHz. The mean velocity of 860 m/s was measured with a single-shot standard deviation of as low as 3.4 m/s and mean velocity uncertainty of 5.5 m/s. NiiFTI is characterized by a long fluorescence lifetime of nitrogen with 1 decay of approximately 50 μs measured in air. The method relies on a single nanosecond laser combined with a high-speed camera, creating an opportunity for the utilization of a typical nitric oxide (NO) laser-induced fluorescence (LIF) experimental setup with minor modifications as well as pulse-burst lasers (PBLs) for ultrahigh repetition rates.
据我们所知，本信函描述了一种新的流动标记方法——一氧化氮（NO）电离诱导流动标记与成像（NiiFTI），并展示了在250kHz下近马赫6高超音速流动中单点测速的首次实验演示。单次测量得到的平均速度为860m/s，标准差低至3.4m/s，平均速度不确定度为5.5m/s。NiiFTI的特点是氮气的荧光寿命长，在空气中测量的1次衰减约为50μs。该方法依赖于单个纳秒激光器与高速相机，为利用典型的一氧化氮（NO）激光诱导荧光（LIF）实验装置并进行微小修改以及利用超高速重复率的脉冲串激光器（PBL）创造了机会。
