针对低雷诺数临界流喷嘴喉径小,几何测量困难,常用的负压式PVTt装置难以对喷嘴进行最大背压比试验等问题,设计了一种以步进电机为动力的主动活塞式气体流量校准器。依据流体力学质量守恒原理,提出按PcTt参数动态检定临界流喷嘴流出系数的方法,建立了数学模型。经比对验证,动态检定方法准确、可行,流出系数Cd的重复性达到(0.02~0.05)%。
Abstract
In view of the shortcomings existed in the low reynolds number critical flow nozzles such as the difficulties of geometric measurement in small throat radius and the test of back pressure ratio on existing PVTt standard facility, an the active piston flow comparator is developed. According to the principle of mass conservation, a flying test method based on PcTt is presented. Test results show that the flying test method is accurate and feasible. The repeatability of discharge coefficient Cd is up to (0.02~0.05)%.
关键词
计量学 /
临界流喷嘴 /
背压比 /
流出系数 /
活塞式校准器
Key words
Metrology /
Critical flow nozzle /
Pressure ratios /
Discharge coefficient /
Piston comparator
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参考文献
[1]王自和.低雷诺数下临界流文丘里喷嘴的背压比[C]//2006年全国流量计量学术交流会,郑州, 2006, 215-221.
[2]JJG 620-2008,临界流文丘里喷嘴 [S].
[3]Kramer R B, Dopheide M D. Actively driven piston prover for the calibration of sonic nozzles[C]//The 14th International Flow Measurement Conference, Flomeko, Johannesburg, 2007, 18-21.
[4]李春辉,王池.音速喷嘴扩散段形状对流出系数的影响[J]. 计量学报, 2008, 29(5):423-426.
[5]李春辉,王池.临界流喷嘴数值模拟研究初探[J]. 计量技术, 2006, (10):7-9.
[6]Wang C, Li X, Duan H M,et al.Establishment of Piston Devices[C]//The 12th International Flow Measurement Conference, Flomeko, Guilin,Guangxi,China, 2004, 14-17.