The Test Facility of the Critical Back-pressure Ratio for Small Sonic Nozzle
ZHOU Li-yuan1,2,LI Chun-hui2,XIE Dai-liang1
1. College of Engineering Measurement, China Jiliang University, Hangzhou, Zhejiang 310018, China
2. National Institute of Metrology, Beijing 100029, China
Abstract：The back pressure ratio of sonic nozzle at work must be lower than critical back-pressure ratio to realize and maintain the critical flow for the sonic nozzle. Therefore, the back pressure ratio of the sonic nozzle when the Reynolds number Red of throat is less than 2×105 should be no bigger than 0.25, or is subjected to make the actual test, which is suggested in ISO 9300. A test facility was built, which can be used to measure the critical back-pressure ratio for the sonic nozzle with throat diameter of 0.3~3mm, while the flow range of sonic nozzle can be 0.05~5m3/h. The expanded uncertainty is 0.56% (k=2).
周立媛,李春辉,谢代梁. 微小音速喷嘴临界背压比测试装置[J]. 计量学报, 2020, 41(1): 43-47.
ZHOU Li-yuan,LI Chun-hui,XIE Dai-liang. The Test Facility of the Critical Back-pressure Ratio for Small Sonic Nozzle. Acta Metrologica Sinica, 2020, 41(1): 43-47.
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2020, Vol. 41 
