Calculation of geometric flow profile correction factor for ultrasonic flow meter using semi-3D simulation technique

Ultrasonics ◽  
2020 ◽  
Vol 106 ◽  
pp. 106165 ◽  
Author(s):  
Seyed Foad Mousavi ◽  
Seyed Hassan Hashemabadi ◽  
Jalil Jamali
Keyword(s):  
Correction Factor ◽  
Simulation Technique ◽  
3D Simulation ◽  
Flow Profile ◽  
Geometric Flow ◽  
Flow Meter ◽  
Profile Correction ◽  
Ultrasonic Flow Meter

Calculation of the Flow Profile Correction Factor Based on Flow Velocity Distribution Functions for Ultrasonic Flow Metering

2019 ◽  
Author(s):  
Sejong Chun
Keyword(s):  
Velocity Distribution ◽  
Flow Velocity ◽  
Transit Time ◽  
Correction Factor ◽  
Distribution Functions ◽  
Flow Profile ◽  
Flow Metering ◽  
Profile Correction ◽  
Velocity Distribution Functions ◽  
Ultrasonic Flow Meter

Abstract Transit-time ultrasonic flow metering relies on the flow profile correction factor (FPCF) to improve its measurement capability by converting line-integrated flow velocity into area-integrated flow velocity. It is because the flow velocity is integrated along ultrasonic paths between ultrasonic sensors by sending and receiving pulse signals in the transit-time ultrasonic flow metering. ISO 12242 (liquid flow metering) and ISO 17089 (gas flow metering) specify how to define the FPCF with a transit-time multi-path ultrasonic flow meter. The FPCF is applied to an averaged value of line-integrated flow velocities, not to each line-integrated flow velocity, according to the ISO standards. The present use of FPCF is validated in the fully-developed turbulent pipe flow, which a long straight pipe is installed upstream of the ultrasonic flow meter. However, the present FPCF would not be very accurate in asymmetric pipe flows with various conduit elements, such as elbows. This study attempts to apply the FPCF to each line-integrated flow velocity in transit-time multi-path ultrasonic flow metering. The FPCF can be applied to each line-integrated flow velocity if the FPCF is based on flow velocity distribution functions, such as those suggested by Salami (1984). The Salami’s flow velocity distribution functions include one symmetric flow, three one-peak flows, and two two-peak flows. The FPCF is calculated by line-integrals along the ultrasonic paths on each flow velocity distribution function. This study is the first attempt to show that the FPCF can be applied to convert the line-integrated flow velocities into the area-integrated flow velocity along each ultrasonic path.

The Effect of Duct Cross-Sectional Shapes on Metrological Performance of Ultrasonic Flowmeters

2007 ◽  
Author(s):  
Iryna Gryshanova
Keyword(s):  
Correction Factor ◽  
Fluid Velocity ◽  
Flow Characteristics ◽  
Optimum Shape ◽  
Flow Profile ◽  
Axially Symmetric ◽  
Cross Sectional ◽  
Flow Measurements ◽  
Profile Correction ◽  
Ultrasonic Time

This paper describes prospects of measuring range extension on transient and laminar flow regimes for ultrasonic time-of-flight flowmeters due to creation measuring ducts with special cross-sectional shapes. The appropriateness of this idea consists that the flow profile correction factor, which considers a difference between averaged fluid velocity along the path of ultrasound propagation and area-averaged fluid velocity is not identical for laminar, transitive and turbulent conditions. Even on the assumption of axially symmetric flows the correction factor changes more than on 25% at transition from one condition to another. In this connection there was an object in view how to eliminate the influence of a velocity profile on accuracy of ultrasonic flow measurements. For that computer models of ultrasonic meters with several variants of cross-sections have been developed and due to CFD techniques the flow profile sensitivities of various meter configurations are investigated in different Reynolds number flows. The selection of optimum shape of the measuring duct for ultrasonic flowmeters has been appraised based on getting of as much as possible stable correction factor in a wide flow range and the minimal pressure loss on a meter. Results show that ultrasonic flowmeters with specially designed duct shapes could be used for increasing accuracy of non-liquid meter calibration and also for elimination of the error caused by variations of hydrodynamic flow characteristics.

scholarly journals Influence of Flow Disturbances behind the 90° Bend on the Indications of the Ultrasonic Flow Meter with Clamp-On Sensors on Pipelines

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 868
Author(s):  
Piotr Synowiec ◽  
Artur Andruszkiewicz ◽  
Wiesław Wędrychowicz ◽  
Piotr Piechota ◽  
Elżbieta Wróblewska
Keyword(s):  
Correction Factor ◽  
Measurement Errors ◽  
Laser Doppler Anemometry ◽  
Reynolds Numbers ◽  
Flow Meter ◽  
Flow Disturbances ◽  
Measurement Plane ◽  
Ultrasonic Flow Meter ◽  
The Subject ◽  
The Given

The subject matter of the article concerns velocities/flow rate measurements in the area of disturbed flows-behind the 90° bend. They were conducted by means of an ultrasonic flowmeter with clamp-on sensors on pipeline, for water and two different Reynolds numbers of 70,000 and 100,000, corresponding to two velocities of approximately 1.42 m/s and 2.04 m/s. The tests were carried out at 12 distances from the disturbance. Sensors on the circumference of the pipeline were mounted 30° each. The correction factor values were calculated for the given measurement geometry. The measurements have shown that the values of this coefficient are always greater than 1, which means that the ultrasonic flow meter understates the speed values. They also showed that already at a distance of 8 nominal diameters from the disturbance, the correction factor does not exceed 1.02, so the measurement errors are within the maximum permissible error (MPE) of a typical ultrasonic flow meter. For distances less than eight nominal diameters from the disturbance, not taking the correction factor value into the account can lead to systematic errors of up to 10.8%. Studies have also proved that in each measurement plane behind the disturbance there are two mounting angles for the ultrasonic sensors, 60° and 240° respectively, for which the correction factor values are minimal. Additionally, using the laser Doppler anemometry (LDA) method, velocity solids were determined at individual distances from the disturbance, and the projections of velocity blocks on the appropriate plane represented velocity profiles and indicated the distances from the disturbance at which these profiles stabilise.

In-Situ Calibration for Feedwater Flow Measurement

2002 ◽  
Author(s):  
David Peyvan ◽  
Yuri Gurevich ◽  
Charles T. French
Keyword(s):  
Velocity Profile ◽  
Flow Measurement ◽  
Cross Correlation ◽  
Operating Conditions ◽  
Integration Scheme ◽  
Flow Meter ◽  
In Situ Calibration ◽  
Profile Correction ◽  
Ultrasonic Flow Meter

With the approval by the Nuclear Regulatory Commission (NRC), of the Appendix K power uprates, it has become important to provide an accurate measurement of the feedwater flow. Failure to meet documented requirements can now more easily lead to plant operations above their analyzed safety limits. Thus, the objective of flow instrumentation used in Appendix K uprates, becomes one of providing precise measurements of the feedwater mass flow that will not allow the plant to be overpowered, but will still assure that maximum licensed thermal output is achieved. The NRC has licensed two technologies that meet these standards. Both are based on ultrasonic measurements of the flow. The first of these technologies, which is referred to as transit-time, relies on the measurement of differences in time for multiple ultrasonic beams to pass up and downstream in the fluid stream. These measurements are then coupled with a numerical integration scheme to compensate for distortions in the velocity profile due to upstream flow disturbances. This technology is implemented using a spool piece that is inserted into the feedwater pipe. The second technology relies on the measurement of the velocity of eddies within the fluid using a numerical process called cross-correlation. This technology is implemented by attaching the ultrasonic flow meter to the external surface of the pipe. Because of the ease in installation, for atypical situations, distortions in the velocity profile can be accounted for by attaching a second ultrasonic flow meter to the same pipe or multiple meters to a similar piping configuration, where the flow is fully developed. The additional meter readings are then used for the calibration of the initial set-up. Thus, it becomes possible to provide an in-situ calibration under actual operating conditions that requires no extrapolation of laboratory calibrations to compensate for distortions in the velocity profile. This paper will focus on the cross-correlation method of flow measurement, starting with the theoretical bases for the velocity profile correction factor and its reliance on only the Reynolds number to produce an accurate measurement of the flow, when the flow is fully developed. The method of laboratory calibration and the verification of these calibrations under actual plant operating conditions will be discussed. This will be followed by a discussion of how this technology is being used today to support the Appendix K uprates. Various examples will be presented of piping configurations, where in-situ calibrations have or will be used to provide an accurate measurement of the feedwater flow at a specific location.

scholarly journals Performance optimization of ultrasonic flow meter based on computational fluid dynamics

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879326 ◽  
Author(s):  
Shanbi Peng ◽  
Wen Liao ◽  
Huan Tan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Performance Optimization ◽  
Evaluation Method ◽  
Flow Meter ◽  
Rectification Effect ◽  
Ultrasonic Flow Meter ◽  
Accuracy Of Measurement ◽  
Nature Gas ◽  
Measuring Tool

As a common nature gas measuring tool, ultrasonic flow meter is more and more put into use. Therefore, the accuracy of measurement is what we concern the most. The performance of ultrasonic flow meter is closely related to fluid state which flows through it. This article identified the evaluation method of rectification effect of gasotron and its implementation steps. It proposed an assessing index Lmin based on dichotomy. Computational fluid dynamics method is used to simulate the model of an upstream straight pipe section with a header and plate gasotron, which obtained the assessing index Lmin in five different transmission conditions. Finally, the feasibility of the gasotron is validated against comparing indication errors in different installation conditions: with a header, benchmark, with a header and gasotron.

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