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.

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.

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.

Gravimetric Calibration of Critical Flow Venturi Nozzles

Volume 1 ◽  
2004 ◽  
Author(s):  
Thomas B. Morrow
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Discharge Coefficient ◽  
Computer Code ◽  
Critical Flow ◽  
Calibration Data ◽  
Sonic Nozzle ◽  
Flow Meters ◽  
Southwest Research Institute ◽  
Layer Flow

The Metering Research Facility (MRF) was commissioned in 1995/1996 at Southwest Research Institute for research on, and calibration of natural gas flow meters. A key commissioning activity was the calibration of critical flow Venturi (sonic) nozzles by a gravimetric proving process flowing nitrogen or natural gas at different pressures. This paper concerns the calibration of the four sonic nozzles installed in the MRF Low Pressure Loop (LPL). Recently, a new project prompted a review of the relations used to calculate sonic nozzle discharge coefficient in the LPL data acquisition computer code. New calibrations of the LPL sonic nozzles were performed flowing natural gas over a lower range of pressure than used in the original commissioning tests. The combination of new and old gravimetric calibration data are shown to agree well with correlations published by Arnberg and Ishibashi (2001) and by Ishibashi and Takamoto (2001) for laminar, transitional and turbulent boundary layer flow in critical flow Venturi nozzles.

New Discharge Coefficient of Throat Tap Nozzle Based on ASME Performance Test Code 6 for Reynolds Number From 2.4 × 105 to 1.4 × 107

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Noriyuki Furuichi ◽  
Kar-Hooi Cheong ◽  
Yoshiya Terao ◽  
Shinichi Nakao ◽  
Keiji Fujita ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Discharge Coefficient ◽  
Performance Test ◽  
Reynolds Numbers ◽  
Experimental Results ◽  
National Metrology Institute ◽  
Reference Curve ◽  
Number Range ◽  
Discharge Coefficients

The throat tap nozzle of the American Society of Mechanical Engineers performance test code (ASME PTC) 6 is widely used in engineering fields, and its discharge coefficient is normally estimated by an extrapolation in Reynolds number range higher than the order of 107. The purpose of this paper is to propose a new relation between the discharge coefficient of the throat tap nozzle and Reynolds number by a detailed analysis of the experimental data and the theoretical models, which can be applied to Reynolds numbers up to 1.5 × 107. The discharge coefficients are measured for several tap diameters in Reynolds numbers ranging from 2.4 × 105 to 1.4 × 107 using the high Reynolds number calibration rig of the National Metrology Institute of Japan (NMIJ). Experimental results show that the discharge coefficients depend on the tap diameter and the deviation between the experimental results and the reference curve of PTC 6 is 0.75% at maximum. New equations to estimate the discharge coefficient are developed based on the experimental results and the theoretical equations including the tap effects. The developed equations estimate the discharge coefficient of the present experimental data within 0.21%, and they are expected to estimate more accurately the discharge coefficient of the throat tap nozzle of PTC 6 than the reference curve of PTC 6.

scholarly journals Is an ADHD Observation-Scale Based on DSM Criteria Able to Predict Performance in a Virtual Reality Continuous Performance Test?

2020 ◽  
Vol 10 (7) ◽  
pp. 2409
Author(s):  
Débora Areces ◽  
Celestino Rodríguez ◽  
Trinidad García ◽  
Marisol Cueli
Keyword(s):  
Virtual Reality ◽  
Attention Deficit ◽  
Performance Test ◽  
Objective Assessment ◽  
Continuous Performance Test ◽  
Performance Tests ◽  
Continuous Performance ◽  
Regression Analyses ◽  
Hyperactivity Disorder ◽  
Observation Scale

The Diagnosis of Attention Deficit/Hyperactivity Disorder (ADHD) requires an exhaustive and objective assessment in order to design an intervention that is adapted to the peculiarities of the patients. The present study aimed to determine if the most commonly used ADHD observation scale—the Evaluation of Attention Deficit and Hyperactivity (EDAH) scale—is able to predict performance in a Continuous Performance Test based on Virtual Reality (VR-CPT). One-hundred-and-fifty students (76% boys and 24% girls) aged 6–16 (M = 10.35; DT = 2.39) participated in the study. Regression analyses showed that only the EDAH subscale referring to inattention symptoms, was a statistically significant predictor of performance in a VR-CPT. More specifically, this subscale showed 86.5% prediction-accuracy regarding performance in the Omissions variable, 80.4% in the Commissions variable, and 74.5% in the Response-time variable. The EDAH subscales referring to impulsivity and hyperactivity were not statistically significant predictors of any variables in the VR-CPT. Our findings may partially explain why impulsive-hyperactive and the combined presentations of ADHD might be considered as unique and qualitatively different sub-categories of ADHD. These results also highlighted the importance of measuring not only the observable behaviors of ADHD individuals, but also the scores in performance tests that are attained by the patients themselves.

Introduction of Improved Orifice Flow Measurement Methods in ASME PTC 19.5

2005 ◽  
Author(s):  
David R. Keyser ◽  
Jeffrey R. Friedman
Keyword(s):  
Flow Measurement ◽  
Discharge Coefficient ◽  
Performance Test ◽  
Dynamic Theory ◽  
Fluid Dynamic ◽  
Theoretical Concept ◽  
Flow Metering ◽  
New Information ◽  
Orifice Flow ◽  
Coefficient Of Discharge

This paper presents the new information on orifice flow metering in ASME Performance Test Code (PTC) 19.5, “Flow Measurement” [1], and discusses many of the clarifications that have been made based on experience and commentary to the review drafts of the Code. In particular, this paper expounds upon details regarding piping installation requirements for accurate measurement. A major advancement incorporated into ASME PTC 19.5 is the development of a coefficient of discharge equation that is based on fluid dynamic theory. The theoretical concept and a summary of the derivation of the new discharge coefficient equation for orifices are presented in this paper. It is shown that the calibration interpretation methodology introduced in PTC 19.5, which is similar to that developed earlier for nozzle calibrations, reduces the uncertainty of calibrated orifice metering sections, even when used outside the calibration range.

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

scholarly journals Fish larvae exploit edge vortices along their dorsal and ventral fin folds to propel themselves

2016 ◽  
Vol 13 (116) ◽  
pp. 20160068 ◽  
Author(s):  
Gen Li ◽  
Ulrike K. Müller ◽  
Johan L. van Leeuwen ◽  
Hao Liu
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
Bony Fish ◽  
The Body ◽  
Functional Explanation ◽  
Image Velocimetry ◽  
Median Fins

Larvae of bony fish swim in the intermediate Reynolds number ( Re ) regime, using body- and caudal-fin undulation to propel themselves. They share a median fin fold that transforms into separate median fins as they grow into juveniles. The fin fold was suggested to be an adaption for locomotion in the intermediate Reynolds regime, but its fluid-dynamic role is still enigmatic. Using three-dimensional fluid-dynamic computations, we quantified the swimming trajectory from body-shape changes during cyclic swimming of larval fish. We predicted unsteady vortices around the upper and lower edges of the fin fold, and identified similar vortices around real larvae with particle image velocimetry. We show that thrust contributions on the body peak adjacent to the upper and lower edges of the fin fold where large left–right pressure differences occur in concert with the periodical generation and shedding of edge vortices. The fin fold enhances effective flow separation and drag-based thrust. Along the body, net thrust is generated in multiple zones posterior to the centre of mass. Counterfactual simulations exploring the effect of having a fin fold across a range of Reynolds numbers show that the fin fold helps larvae achieve high swimming speeds, yet requires high power. We conclude that propulsion in larval fish partly relies on unsteady high-intensity vortices along the upper and lower edges of the fin fold, providing a functional explanation for the omnipresence of the fin fold in bony-fish larvae.

Turbulent Transport in Pin Fin Arrays: Experimental Data and Predictions

2005 ◽  
Author(s):  
F. E. Ames ◽  
L. A. Dvorak
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Boundary Layers ◽  
Fluid Dynamic ◽  
Turbulent Transport ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Pin Fin ◽  
Pin Fin Arrays

The objective of this research has been to experimentally investigate the fluid dynamics of pin fin arrays in order to clarify the physics of heat transfer enhancement and uncover problems in conventional turbulence models. The fluid dynamics of a staggered pin fin array have been studied using hot wire anemometry with both single and x-wire probes at array Reynolds numbers of 3000; 10,000; and 30,000. Velocity distributions off the endwall and pin surface have been acquired and analyzed to investigate turbulent transport in pin fin arrays. Well resolved 3-D calculations have been performed using a commercial code with conventional two-equation turbulence models. Predictive comparisons have been made with fluid dynamic data. In early rows where turbulence is low, the strength of shedding increases dramatically with increasing in Reynolds numbers. The laminar velocity profiles off the surface of pins show evidence of unsteady separation in early rows. In row three and beyond laminar boundary layers off pins are quite similar. Velocity profiles off endwalls are strongly affected by the proximity of pins and turbulent transport. At the low Reynolds numbers, the turbulent transport and acceleration keep boundary layers thin. Endwall boundary layers at higher Reynolds numbers exhibit very high levels of skin friction enhancement. Well resolved 3-D steady calculations were made with several two-equation turbulence models and compared with experimental fluid mechanic and heat transfer data. The quality of the predictive comparison was substantially affected by the turbulence model and near wall methodology.

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