1. College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou, Zhejiang 310018, China
2. National Institute of Metrology, Beijing 100029, China
3. Facility Design and Instrumentation Institute of China Aerodynamics Research and Development Center, Mianyang, Sichuan 621000, China
Abstract:In order to clarify the applicability of the low-speed results of the laser Doppler velocimeter (LDV) calibrated by the spinning-disc facility, it is analyzed that the uncertainty of velocity depends on the uncertainty of both the interference fringe spacing in the measuring volume and Doppler frequency. As the Interference fringe spacing is independent of the fluid velocity the possible difference of uncertainty in between the high velocity and the low velocity is only related with the Doppler frequency algorithm at different velocity. The uncertainty of Doppler frequency caused by the algorithm at different velocity is analyzed with Monte Carlo method (MCM) for evaluation of measurement uncertainty. The result shows that the relative uncertainty of the Doppler frequency caused by the algorithm is less than 0.03% in the range of 0.1~340m/s.The obvious difference of uncertainty has not been found in the different points of velocity investigated. The budget resulting from Doppler frequency accuracy to the uncertainty of velocity measured is less than 0.013%. It is concluded that the calibration result at low velocity is also reasonable to be used at high velocity measurement.
张育闻,崔骊水,谢代梁,杨兆欣. 基于LDV测速算法的多普勒频率测量不确定度分析和评定[J]. 计量学报, 2023, 44(4): 591-597.
ZHANG Yu-wen,CUI Li-shui,XIE Dai-liang,YANG Zhao-xin. Analysis and Evaluation on the Uncertainty of Doppler Frequency Measurement Based on LDV Velocity Measurement Algorithm. Acta Metrologica Sinica, 2023, 44(4): 591-597.
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