A Generalized Discharge Coefficient for Differential Pressure Type Fluid Meters

1974 ◽  
Vol 96 (4) ◽  
pp. 440-448 ◽  
Author(s):  
R. P. Benedict ◽  
J. S. Wyler
Keyword(s):  
Discharge Coefficient ◽  
Pipe Wall ◽  
Reynolds Numbers ◽  
Generalized Equation ◽  
Differential Pressure ◽  
Rational Basis ◽  
Flow Meters ◽  
Type Flow ◽  
New Formulation ◽  
Calibration Laboratories

A generalized rational equation is derived for the discharge coefficient of differential pressure-type fluid meters. Its factors are particularized for throat tap meters, pipe wall tap nozzles, and for orifice-type flow meters. Comparisons are made with available theories and with current Fluid Meter practices, and these support the new formulation. Because of its rational basis, the generalized equation may be useful for extrapolations to Reynolds numbers which lie beyond the capabilities of calibration laboratories.

ASME PTC 19.5 Procedures for Application of Laboratory Calibrations of Differential Pressure Flow Meters

2008 ◽  
Author(s):  
Jeffrey R. Friedman ◽  
David Keyser
Keyword(s):  
Discharge Coefficient ◽  
Performance Test ◽  
Fluid Dynamic ◽  
Reynolds Numbers ◽  
Differential Pressure ◽  
Calibration Data ◽  
Performance Tests ◽  
Regression Analyses ◽  
Flow Meters ◽  
Laboratory Calibration

Performance Test Codes require primary mass flow accuracies that in many applications require the laboratory-quality calibration of differential pressure meters. It is also true that many performance tests are conducted at Reynolds numbers and flows well above the laboratories’ capacities, and sound extrapolation methods had to be developed. Statistical curve-fits and regression analyses by themselves, absent fluid-dynamic foundations, are not valid procedures for extrapolation. The ASME PTC 19.5-2004 discharge coefficient equations presented in this paper are suitable for use and extrapolation of laboratory calibration data.

Loss Coefficients for Fluid Meters

1977 ◽  
Vol 99 (1) ◽  
pp. 245-248 ◽  
Author(s):  
R. P. Benedict
Keyword(s):  
Discharge Coefficient ◽  
Generalized Equation ◽  
Differential Pressure ◽  
Loss Coefficient ◽  
Contraction Coefficient ◽  
Loss Parameter ◽  
Loss Coefficients

A generalized equation is derived which describes the loss coefficient for any differential pressure type fluid meter. This loss coefficient is given in terms of dimensionless factors including: meter geometry, discharge coefficient, contraction coefficient, and diffuser efficiency. The equation applies equally well for venturis, nozzles, and orifices, installed in pipes or with plenum inlets. Another equation is derived which relates the previously published ASME loss parameter for fluid meters to this new generalized loss coefficient.

Extrapolation and Curve-Fitting of Calibration Data for Differential Pressure Flow Meters

2009 ◽  
Vol 132 (2) ◽  
Author(s):  
David R. Keyser ◽  
Jeffrey R. Friedman
Keyword(s):  
Flow Measurement ◽  
Performance Test ◽  
Fluid Dynamic ◽  
Reynolds Numbers ◽  
Differential Pressure ◽  
Calibration Data ◽  
Performance Tests ◽  
Expansion Factor ◽  
Flow Meters ◽  
The One

Performance test codes require primary mass-flow accuracies that in many applications require laboratory quality calibration of differential pressure meters. It is also true that many performance tests are conducted at Reynolds numbers and flows well above the laboratories' capacities, and sound extrapolation methods had to be developed. Statistical curve fits and regression analyses by themselves, absent fluid-dynamic foundations, are not valid procedures for extrapolation. The ASME PTC 19.5-2004 discharge coefficient equations reproduced in this paper for nozzles, orifices, and venturis are suitable for use whenever calibration data are to be applied in a flow measurement and/or extrapolated to higher Reynolds numbers as necessary. The equations may also be used for uncalibrated differential pressure meters by using nominal values. It is necessary to note that the metering runs must be manufactured with dimensions, tolerances, smoothness, etc., and installed in strict accordance with ASME PTC 19.5 for these equations to be valid. Note that for compressible flow, the value of the expansion factor term in the PTC 19.5 equation must be the one corresponding to the published PTC 19.5 equation.

Comparisons Between Throat and Pipe Wall Tap Nozzles

1975 ◽  
Vol 97 (4) ◽  
pp. 569-573 ◽  
Author(s):  
J. S. Wyler ◽  
R. P. Benedict
Keyword(s):  
Reynolds Number ◽  
Discharge Coefficient ◽  
Pipe Wall ◽  
Performance Characteristics ◽  
History Of ◽  
Coefficient Versus ◽  
Nominal Performance ◽  
Independent Calibration ◽  
Calibration Laboratories

The history of pipe wall tap nozzles and throat tap nozzles, as to performance characteristics, is briefly reviewed. A series of tests was conducted on pipe wall tap and throat tap nozzle installations at three independent calibration laboratories. These results are presented, analyzed, and compared with existing rational, empirical, and nominal performance characteristics in the form of discharge coefficient versus the throat Reynolds number. On the basis of these results, a recommendation is made that both pipe wall tap and throat tap nozzle installations be considered as equally accurate for use in precision fluid metering work.

Approximation of the discharge coefficient of differential pressure flowmeters using different soft computing strategies

2021 ◽  
Vol 79 ◽  
pp. 101913
Author(s):  
Zhanat Dayev ◽  
Aiat Kairakbaev ◽  
Kaan Yetilmezsoy ◽  
Majid Bahramian ◽  
Parveen Sihag ◽  
...  
Keyword(s):  
Soft Computing ◽  
Discharge Coefficient ◽  
Differential Pressure

Theory to Help the Use of Electromagnetic Flow Meters

2002 ◽  
Author(s):  
Xiao-Zhang Zhang
Keyword(s):  
Pipe Wall ◽  
Three Dimensional ◽  
Electromagnetic Properties ◽  
Reasonable Accuracy ◽  
Flow Meter ◽  
Flow Meters ◽  
Electromagnetic Flow ◽  
Gas Liquid Flow ◽  
Electromagnetic Flow Meter ◽  
Theory Research

Compared with other flow meters, the theory of electromagnetic flow meter is well developed. Until now, we are able to predict the three dimensional characteristics of this kind of flow meters with reasonable accuracy. This has given much help to the designers to improve the flow meters. On the other hand, the theory can offer a tool for the users of this kind of flow meters to judge the application situations, estimate the possible measurement error, etc. This paper introduces the recent work of the author on the theory of the electromagnetic flow meter. The basic physical conceptions and equations are given with a brief history review of the theory research. Several examples are given of using the theory to analyze the meters’ behavior in different application situations. They are: effect of the conducting pipe connections; errors caused by a pipe wall of different electromagnetic properties; gas-liquid flow and errors caused by a relative motion of the probe.

Loss Characteristics of Orifices and Nozzles

1978 ◽  
Vol 100 (3) ◽  
pp. 299-307 ◽  
Author(s):  
S. H. Alvi ◽  
K. Sridharan ◽  
N. S. Lakshmana Rao
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Flow Regime ◽  
Discharge Coefficient ◽  
Critical Reynolds Number ◽  
Reynolds Numbers ◽  
Center Line ◽  
Laminar Regime ◽  
Variation Of Parameters ◽  
Turbulent Flow Regime

Loss characteristics of sharp-edged orifices, quadrant-edged orifices for varying edge radii, and nozzles are studied for Reynolds numbers less than 10,000 for β ratios from 0.2 to 0.8. The results may be reliably extrapolated to higher Reynolds numbers. Presentation of losses as a percentage of meter pressure differential shows that the flow can be identified into fully laminar regime, critical Reynolds number regime, relaminarization regime, and turbulent flow regime. An integrated picture of variation of parameters such as discharge coefficient, loss coefficient, settling length, pressure recovery length, and center line velocity confirms this classification.

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