Discharge Coefficient Correlations fir Circular-Arc Venturi Flowmeters it Critical (Soiic) Flow
Discharge Coefficient Correlations fir Circular-Arc Venturi Flowmeters it Critical (Soiic) Flow
复制标题
圆弧文丘里流量计与临界 (Soiic) 流量的流量系数相关性
DOI：
10.1115/1.3447117
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
W. Seidl
中科院分区：
文献类型：
--
作者：
T. Arnberg;C. Britton;W. Seidl
给出的数据倾向于验证理论预测的在喉道雷诺数大于1.5 105的临界流态（声波）下工作的圆弧文丘里流量计的流量系数。使用目前正在进行国际标准化的方法对数据进行了广泛的分析。这些数据有助于验证从层流过渡到湍流边界层时流量系数下降0.25%的理论预测。过渡发生在喉道雷诺数为2.2 106时，但过渡点可能由于几种影响而发生变化。实测数据的平均值落在层流边界层和湍流边界层的理论值之间。从4-1 - 10i到34 lCfi的雷诺数平均线方程中，55个数据点的散点为±0.212%（95%置信水平），其中包括几个变量的影响。数据来自17个喉部尺寸从0.15到1.37 in的Venturis。贝塔比率在0.014- 0.25之间。使用了四种不同的测试气体和三种主要流量测量设备。附加数据延伸到喉部雷诺数为1.8 104和喉部直径为0.05英寸。这表明了这些地区的特殊问题。测量文丘里喉部直径的技术状况对相关工作提出了主要限制。在许多情况下，根据不同的参数和要求进行校准是必要的。需要进一步研究低雷诺数时的最佳几何参数，β比大于0.1时的最佳进气道构型，表面粗糙度对流量系数的影响，以及各种操作变量（如流动脉动和进气道速度剖面）的影响。此外，随着更好的气体性质数据的出现，应该不断努力改进实际气体的临界流动函数，并将这些计算扩展到更大的压力和温度范围，以及其他气体。
Data are presented which tend to verify the theoretically predicted discharge coefficients for circular-arc venturi flow meters operating in the critical flow regime (sonic) at throat Reynolds numbers above 1.5 105. Extensive analysis of the data is presented using methods that are presently in process of international standardization. The data lend to verify the theoretically predicted decrease of 0.25 percent in the discharge coefficient during transition from laminar to a turbulent boundary layer. The transi tion occurred at a throat Reynolds number of 2.2 106, but the transition point probably changes as a function of several influences. The mean line of the measured data fell between the theoretical values for laminar and turbulent boundary layers. The scatter in 55 data points was ±0.212 percent (95 percent confidence level) from the mean line equation for Reynolds numbers from 4-1 10i to 34 lCfi, which included the effects of several variables. Data were obtained from 17 Venturis with throat sizes from 0.15 to 1.37 in. with Beta ratios ranging from 0.014- to 0.25. Four different test gases and three primary flow measurement facilities were used. Additional data are presented extending down to throat Reynolds numbers of 1.8 104 and throat diameters of 0.05 in. which indicate special problems in these regions. The state of the art for measuring venturi throat diameters presented a major limitation to the correlation effort. Cali bration is necessary in many cases depending on various parameters and requirements. Additional study is needed to determine the optimum geometrical parameters at low Reynolds numbers, the optimum approach configuration for Beta ratios above 0.1, the effect of surface roughness on the discharge coefficient, and the effect of various operational variables such as flow pulsation and approach velocity profile. Also, a continuous effort should be made to improve the critical flow functions for real gases as better gas property data become available, and to extend these calculations to broader ranges of pressures and temperatures, and to other gases.