Selective two-photon absorptive resonance femtosecond laser electronic excitation tagging (STARFLEET) velocimetry is characterized for the first time at high-pressure, low-temperature conditions. Studies were carried out in the NASA Langley Research Center’s 0.3 meter transonic, cryogenic wind tunnel, with flow conditions spanning the entire operational envelope of the facility; total pressures ranging from 100 kPa to 517 kPa, total temperatures from 80 K to 327 K, and Mach numbers from 0.2 to 0.85. STARFLEET signal intensity and lifetime measurements are examined for their thermodynamic dependencies since both intensity and lifetime have implications for measurement precision. Signal intensity is found to be inversely proportional to density, while lifetime scales nearly linearly with density until approaching the liquid-vapor saturation point of nitrogen. The velocity measurement accuracy and precision are assessed over the full domain of conditions, and standard error was det...

中文翻译：

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高压低温风洞中氮气的非播种测速：第三部分。共振飞秒激光标记

选择性双光子吸收共振飞秒激光电子激发标记（STARFLEET）测速仪的首次特点是在高压，低温条件下。研究是在NASA兰利研究中心的0.3米跨音速低温风洞中进行的，其流动条件跨越了该设施的整个运行范围。总压力为100 kPa至517 kPa，总温度为80 K至327 K，马赫数为0.2至0.85。对STARFLEET信号强度和寿命测量值的热力学依赖性进行了检查，因为强度和寿命都对测量精度有影响。发现信号强度与密度成反比，而寿命几乎与密度成线性比例关系，直到接近氮的液体蒸汽饱和点。在整个条件范围内评估速度测量的准确性和精度，并确定了标准误差。