Survey of Primary Flow Measurement Parameters at the NASA Langley Transonic Dynamics Tunnel
Survey of Primary Flow Measurement Parameters at the NASA Langley Transonic Dynamics Tunnel
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NASA 兰利跨音速动力学隧道一次流量测量参数调查
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
David J. Piatak
中科院分区：
文献类型：
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作者：
David J. Piatak
在设施从氟利昂-12重气试验介质改装为R-134a之后的校准活动中，对用于测量NASA兰利跨音速动力学隧道内主要流动条件的方法和位置进行了评估。在风洞沉降室、真空室和收缩段的许多相关位置进行了静压、静压和静温的测量，并将这些测量结果与现有一次流测量系统的测量结果进行了比较。在沉降室中用皮托管探头测量了局部流速。结果表明，一次隧洞流量的实测值与实测值之间存在较小的偏差。隧道停滞压力、正压送风系统压力和停滞温度的这些差异被发现大约为+/-1-3PSF和2-3华氏度。已知的仪器误差在测量的一次流条件下的传播及其对隧道马赫数、动压、流速和雷诺数的影响已被分析研究，并表明在考虑测量的试验段条件的不确定性时需要特别注意。
An assessment of the methods and locations used to measure the primary flow conditions in the NASA Langley Transonic Dynamics Tunnel was conducted during calibration activities following the facility conversion from a Freon-12 heavy-gas test medium to R-134a. A survey of stagnation pressure, plenum static pressure, and stagnation temperature was undertaken at many pertinent locations in the settling chamber, plenum, and contraction section of the wind tunnel and these measurements were compared to those of the existing primary flow measurement systems. Local flow velocities were measured in the settling chamber using a pitot probe. Results illustrate that small discrepancies exist between measured primary tunnel flow conditions and the survey measurements. These discrepancies in tunnel stagnation pressure, plenum pressure, and stagnation temperature were found to be approximately +/- 1-3 psf and 2-3 degrees Fahrenheit. The propagation of known instrument errors in measured primary flow conditions and its impact on tunnel Mach number, dynamic pressure, flow velocity, and Reynolds number have been investigated analytically and shown to require careful attention when considering the uncertainty in measured test section conditions.