临界流文丘里喷嘴测量不确定度分析

Uncertainty Analysis of Critical Flow Venturi Nozzle

介绍了临界流文丘里喷嘴的工作原理,以及用pVTt法气体流量标准装置检定临界流文丘里喷嘴流出系数时的不确定度分析。对于检定过程的不确定度问题,列出了理想条件下的临界流量、实际条件下的临界流量以及喷嘴流出系数不确定度等的数学模型。并对检定过程中喷嘴流出系数的相对拓展不确定度进行了详细的评定,分析了各个因素的来源,便于我们在实际工作中分析影响测量不确定度的主要因素,从而提高我们校准工作的准确度和可靠性。

This paper introduces the working principle of critical flow venturi nozzle and the uncertainty in calibration process using the pVTt gas flow standard facility.It also has given the mathematical models in the verification of venturi nozzle,including of critical flow in ideal conditions,critical flow in actual conditions and the uncertainty of nozzle＇s discharge coefficient, which can help us to research the critical flow venturi nozzles.A detailed assessment of the nozzle＇s discharge coefficient of relative expanded uncertainty in the verification is shown.