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This paper presents a new estimation method to determine the optimal number of transducers using an Ultrasonic Velocity Profile (UVP) for accurate flow rate measurement downstream of a single elbow. Since UVP can measure velocity profiles over a pipe diameter and calculate the flow rate by integrating these velocity profiles, it is also expected to...
Contexts in source publication
Context 1
... UVP method for flow metering systems was developed [10,11]. Figure 1 shows a diagram of the ultrasound propagation involved in the UVP method, which allows instantaneous velocity profiles to be obtained along the ultrasonic beam path. The principle of the flow measurement method is based on the integration of an instantaneous velocity profile over a pipe diameter. ...Context 2
... rate errors versus the number of transducers mounted around the pipe outer wall are plotted in Figure 10. The flow rate of "All field" written in the figure is calculated using velocity profiles in both near and far fields. ...Context 3
... CFD code used to simulate a pipe flow downstream of a single elbow was ANSYS FLUNET (Version 13.0). An isometric view of the piping configuration is shown in Figure 11. Secondary flows were estimated at six cross- sections, from the outlet plane of a single elbow (0D) to 5D downstream of a single elbow. ...Context 4
... flows were estimated at six cross- sections, from the outlet plane of a single elbow (0D) to 5D downstream of a single elbow. Table 1 and Figure 12 show the specifications of CFD analysis and a schematic diagram of the mesh layout around the single elbow. ...Context 5
... The computed velocity distributions projected on each cross- section plane from 0 to 5D downstream of a single elbow are shown in Figure 13. It is well known that flow through a pipe elbow results in velocity directions from the inner to the outer wall. ...Context 6
... estimate the decrease ratio of secondary flows depend- ing on the distance from the elbow, averaged absolute veloc- ities projected on one cross-section plane and normalized using the bulk fluid velocity were employed. These averaged velocities are shown in Figure 14 with the distance from the elbow on the abscissa. Since the decrease ratio between 0 and 1D is significant, numerous transducers were thought to be required for accurate flow rate metering at 1D. ...Context 7
... Velo- city profiles at 1 and 5D along the ultrasonic beam path are illustrated in Figures 15 and 16. As shown in Figure 15(a), the velocity profile at φ = 90 • varied strongly in the far field, because these velocities were affected by the significant secondary flow between two vortexes, as shown in Figure 13(b). ...Context 8
... city profiles at 1 and 5D along the ultrasonic beam path are illustrated in Figures 15 and 16. As shown in Figure 15(a), the velocity profile at φ = 90 • varied strongly in the far field, because these velocities were affected by the significant secondary flow between two vortexes, as shown in Figure 13(b). The velocity profile at φ = 270 • formed a different shape compared with φ = 90 • , since most velocities along the vertical line traversing the center of the pipe in Figure 13(b) pointed upward. ...Context 9
... city profiles at 1 and 5D along the ultrasonic beam path are illustrated in Figures 15 and 16. As shown in Figure 15(a), the velocity profile at φ = 90 • varied strongly in the far field, because these velocities were affected by the significant secondary flow between two vortexes, as shown in Figure 13(b). The velocity profile at φ = 270 • formed a different shape compared with φ = 90 • , since most velocities along the vertical line traversing the center of the pipe in Figure 13(b) pointed upward. ...Context 10
... shown in Figure 15(a), the velocity profile at φ = 90 • varied strongly in the far field, because these velocities were affected by the significant secondary flow between two vortexes, as shown in Figure 13(b). The velocity profile at φ = 270 • formed a different shape compared with φ = 90 • , since most velocities along the vertical line traversing the center of the pipe in Figure 13(b) pointed upward. Conversely, where the transducer was mounted at φ = 0 or 180 • , these velocity profiles were almost the same due to the lateral symmetric flow. ...Context 11
... where the transducer was mounted at φ = 0 or 180 • , these velocity profiles were almost the same due to the lateral symmetric flow. The velocity profile fluctuation obtained at 5D, as shown in Figure 16, was smaller than those at 1D, because the velocity of the secondary flow between two vortexes was also smaller, as illustrated in Figure 13(f). ...Context 12
... where the transducer was mounted at φ = 0 or 180 • , these velocity profiles were almost the same due to the lateral symmetric flow. The velocity profile fluctuation obtained at 5D, as shown in Figure 16, was smaller than those at 1D, because the velocity of the secondary flow between two vortexes was also smaller, as illustrated in Figure 13(f). ...Context 13
... along the Measuring Circle. Figure 17 shows velocity profiles along each measuring circle at 1D. The horizontal axis is the transducer circumferential position and the vertical axis is the time-averaged velocity normalized by the mean velocity. ...Context 14
... horizontal axis is the transducer circumferential position and the vertical axis is the time-averaged velocity normalized by the mean velocity. The velocity profiles fluctuated locally at φ = 90 and 270 • , while high frequency fluctuation emerged at φ = 90 • due to the vertexes shown in Figure 13(b). Conversely, at 5D (see in Figure 18) the frequency declined due to the decreasing vortexes effect. ...Context 15
... velocity profiles fluctuated locally at φ = 90 and 270 • , while high frequency fluctuation emerged at φ = 90 • due to the vertexes shown in Figure 13(b). Conversely, at 5D (see in Figure 18) the frequency declined due to the decreasing vortexes effect. ...Context 16
... flow conditions formed in these simulations were expected to be asymmetrical along a line through maximum values appeared between N w = 5 and 7 for the 1D case (see Figure 19). In addition, the Fourier amplitudes declined remarkably at over N w = 10, and it is expected that approximately twenty transducers will be required to measure the flow rate accurately, considering the sampling theorem. ...Context 17
... to investigate the effect of circumferential transducer position φ on the flow rate measurement error, the transducer position was varied by 3 • and the flow rate was calculated at the each position. Figures 21 and 22 plot both maximum and minimum flow rate errors at 1 and 5D versus the number of transducers for Re = 5 × 10 6 . As shown in Figure 21, these maximum and minimum flow rate errors converged when the number of transducers was approximately twenty. ...Context 18
... 21 and 22 plot both maximum and minimum flow rate errors at 1 and 5D versus the number of transducers for Re = 5 × 10 6 . As shown in Figure 21, these maximum and minimum flow rate errors converged when the number of transducers was approximately twenty. This result is consistent with the estimated number of transducers using FFT analysis. ...Context 19
... converted values of flow rate errors are approximately +5 and −6% for the near and far field, respectively. This is because the patterns of secondary flows, as shown in Figures 13(a) and 13(b), changed significantly depending on the distance from the elbow and the velocity measuring points in the near and far fields were located at different streamwise positions. ...Similar publications
An experimental investigation was performed to investigate two-dimensional axial velocity field at downstream of the 90 ̊ double bend pipe with and with-out inlet swirling condition. The main objectives are to find separation region and observe the influence of inlet swirling flow on the velocity fluctuation using ultrasound technique. The experime...
Citations
... The most important parameters which affect the flowmeter accuracy and calibration factor are pipe roughness [11], transducers spacing [6,11,12] and transducers circumferential position in asymmetrical flow profile [13]. ...
... The AGA-9 and ISO-17089 recommended long straight pipe equal to at least 50 times pipe diameter (50D where D is pipe diameter) to assure fully developed symmetrical velocity profile at flowmeter location [18]. But, due to space constraints and piping restrictions, providing long enough straight pipe at upstream of the flowmeter is sometimes impractical and the flowmeter is not always located in ideal position [4,13,14]. ...
... In such condition, the circumferential placement of transducers pairs on the pipe plays an important role in measurement accuracy [13,19,20]. In asymmetrical flow velocity profile, since the single acoustic beam travers centerline of the pipe section, complexity and asymmetric in flow profile are not taken into the account and the measurement is not precise [4,21,22]. ...
There are several ultrasonic flowmeter technologies such as transient time, cross-correlation, Doppler and etc. The performance of different types of ultrasonic flowmeters under disturbed flow profile due to elbow at upstream has been well studied recently except the cross-correlation type. The ultrasonic cross-correlation flowmeter (UCCF) has different mechanism of flow measurement in comparison with other types of ultrasonic flowmeters that strongly requires its own studies. In case of disturbed flow profile in pipe, due to asymmetrical velocity profile, the UCCF accuracy and required calibration factor are strongly dependent on the circumferential position of ultrasonic transducers on the pipe. Study on UCCF transducers circumferential position and specifying transducers proper position could incredibly improve the UCCF accuracy. The effect of transducers circumferential position on the accuracy in both single path and multipath has not been investigated for a UCCF so far. In this work, Computational Fluid Dynamics (CFD) simulations were conducted using turbulence model of RSM (Reynolds Stress Model) Stress-ω to simulate the asymmetrical air flow profile inside the elbow and the connected straight pipe in order to study the effect of circumferential position of transducers on calibration factor for special type of ultrasonic flowmeters ,UCCF, at different Reynolds numbers and various locations of flowmeter, for the first time. Moreover, the effects of Reynolds numbers and the flowmeter distances from the elbow on the calibration factor were analyzed. Finally, based on calculated calibration factors at different transducer circumferential positions, the best transducers arrangement at different flowmeter locations were proposed for single and multipath cross-correlation flowmeter. Also, in multipath ultrasonic cross correlation flowmeter, the optimum number of transducers were investigated.
... If the flow is axially symmetric, the accurate flow rate Q(t) can be obtained accurately by integrating only the half of the velocity profile using Eq. (15), which is obtained from the measuring line going through the center of the pipe [15][16]. ...
... For comparative performance, the necessary background of each noise is explained. WGN is well known in communication systems to model the ambient variance for virtually any signal processing method [16]. It has the identity distributed probability density function (PDF) pWGN, and it cannot be predicted. ...
An ultrasonic Velocity Profile (UVP) has been continuously improved for flowrate measurements. Since the UVP can visualize a flow profile along a cross section of pipelines, it provides a significant advantage over other conventional methods such as differential pressure, turbine, and vortex. Previously, the UVP was realized by means of autocorrelation, fast Fourier transform, and wavelet as the signal-processing method. An Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT) has been widely used in a field of communication engineering for a high-resolution signal processing. This is the first of utilizing the ESPRIT technique in fluid mechanics for a flowrate computation. To guarantee the proposed idea, the results were compared with a standard electromagnetic flowmeter. Lab experiments were required to demonstrate the accuracy of flowrate measurements.
... The reected echoes are then received and monitored by their ears. Bats use echolocation techniques to calculate their own position relative to objects [1,2] Echolocation can be useful in a variety of applications Manuscript received on February 10, 2016 ; revised on February 15, 2016 medical systems, and, ow measurements,345. In addition, echolocation has been developed for a wide range of applications such as radar, sonar and ultra- sonic678 . ...
This paper presents a method to locate a moving
object with velocities in three dimensional (3D)
spaces by echolocation. This method can determine
the object's position and velocity measurements,
through computation from the original nonlinear
model using a linear least square (LLS) - based
approach. To satisfy the navigation problem and deal
with the additive noise, Colored Gaussian Noise was
considered as a performance parameter in computer
simulations. The design system consisted of one loudspeaker
and four acoustical microphones. An echo
received from the microphone was converted into a
one-bit stream, based on four channels, delta-sigmamodulation
board. A eld-programmable gate array
(FPGA) was then applied to compute the recursive
cross correlation, using one-bit signal processing. The
object, considered as a ying ball, was positioned in
3D space at x-y-z coordinates. The dilution of precision
and the uncertainty in the object position were
also studied. The velocity of the object was calculated
using a pair of linear-period-modulated ultrasonic
signals. The validity was evaluated by the probability
density function (PDF) and the cumulative
density function (CDF) from repeated experimental
results. The results of this proposed system using
an LLS-based method can provide better repeatability,
when compared against the linearization-based
method.
... The reected echoes are then received and monitored by their ears. Bats use echolocation techniques to calculate their own position relative to objects [1,2] Echolocation can be useful in a variety of applications Manuscript received on February 10, 2016 ; revised on February 15, 2016 medical systems, and, ow measurements,345. In addition, echolocation has been developed for a wide range of applications such as radar, sonar and ultra- sonic678 . ...
This paper presents a method to locate a moving object with velocities in three dimensional (3D) spaces by echolocation. This method can determine the object's position and velocity measurements , through computation from the original non-linear model using a linear least square (LLS)-based approach. To satisfy the navigation problem and deal with the additive noise, Colored Gaussian Noise was considered as a performance parameter in computer simulations. The design system consisted of one loudspeaker and four acoustical microphones. An echo received from the microphone was converted into a one-bit stream, based on four channels, delta-sigma-modulation board. A eld-programmable gate array (FPGA) was then applied to compute the recursive cross correlation, using one-bit signal processing. The object, considered as a ying ball, was positioned in 3D space at x-y-z coordinates. The dilution of precision and the uncertainty in the object position were also studied. The velocity of the object was calculated using a pair of linear-period-modulated ultra-sonic signals. The validity was evaluated by the probability density function (PDF) and the cumulative density function (CDF) from repeated experimental results. The results of this proposed system using an LLS-based method can provide better repeatabil-ity, when compared against the linearization-based method.
... Bats use echolocation techniques to calculate their own position relative to objects [1,2] Echolocation can be useful in a variety of applications Manuscript received on February 10, 2016 ; revised on February 15, 2016. * The Department of Instrumentation and Electronics Engineering King Mongkut University of Technology North Bangkok, Thailand, Email : thnatee@yahoo.co.th 1 involving reections, including non-destructive tests, medical systems, and, ow measurements, [3][4][5]. In addition, echolocation has been developed for a wide range of applications such as radar, sonar and ultrasonic [6][7][8]. ...
This paper presents a method to locate a moving object with velocities in three dimensional (3D) spaces by echolocation. This method can determine the object’s position and velocity measurements, through computation from the original nonlinear model using a linear least square (LLS) - based approach. To satisfy the navigation problem and deal with the additive noise, Colored Gaussian Noise was considered as a performance parameter in computer simulations. The design system consisted of one loudspeaker and four acoustical microphones. An echo received from the microphone was converted into a one-bit stream, based on four channels, delta-sigmamodulation board. A field-programmable gate array (FPGA) was then applied to compute the recursive cross correlation, using one-bit signal processing. The object, considered as a fiying ball, was positioned in 3D space at x-y-z coordinates. The dilution of precision and the uncertainty in the object position were also studied. The velocity of the object was calculated using a pair of linear-period-modulated ultrasonic signals. The validity was evaluated by the probability density function (PDF) and the cumulative density function (CDF) from repeated experimental results. The results of this proposed system using an LLS-based method can provide better repeatability, when compared against the linearization-based method.
This manuscript presents an experimental study to evaluate the applicability of the ultrasonic pulse-train Doppler method (UPTD) to the disturbed flow in a pipe. The UPTD can expand the detectable velocity range compared with the conventional ultrasonic pulse Doppler method and has an advantage of trouble-free installation into conventional hardware. Comparative experiments were conducted using two different transducer frequencies, 1 MHz and 4 MHz. The UPTD was only applied to the 4-MHz condition to expand the velocity range fourfold, which is equal to the velocity range of a 1-MHz transducer. The probability density distributions of the measured velocities were almost the same between 1 MHz and 4 MHz, even though the measurement position was not only downstream of a long straight pipe but also downstream 10 or 5 pipe diameters from an obstacle plate. To estimate the influence of aliasing on the velocity measurement for a large fluctuating flow, experiments using a 2-MHz transducer were also conducted. These results indicated that it is possible to estimate the standard deviation of the velocities measured under the aliasing condition, and the accuracy of flow rate measurement decreases when the standard deviation of the velocity exceeds the measurable velocity by approximately twice. Additionally, the flow rate by the 1-MHz transducer was about −2% smaller than that by the 4-MHz transducer for both the straight pipe and disturbed conditions. Through the validation of the influence of the measurement volume between 1 MHz and 4 MHz conditions, the flow rate difference was found to be likely due to the influences of not only the measurement volume but also the standing wave formed by the pulses reflected on the opposite pipe wall.
At present, magnetic resonance imaging (MRI), which is one of the noninvasive diagnostic imaging techniques for medical use, has been applied to industrial product inspection. In this study, a hydraulic model test system, called the “flow phantom system,” which can generate steady flow and oscillating flow for time-resolved MRI, was developed to aid optimum design of fluid machinery. Simple flow phantoms are tested under laminar flow or oscillating flow to evaluate the validity and effectiveness of the proposed system. In this article, the test results of double cylindrical pipe flow, elbow pipe flow, cylindrical valve flow, and jet pump flow, which are often seen in fluid machines, are tested using the 2D time-spatial labeling inversion pulse (Time-SLIP) method, which can track a labeled water mass and visualize it using two-dimensional images. MRI-detected flow patterns were compared with particle image velocimetry (PIV) or numerical simulation.
In this present study, we developed a new two-dimensional velocity profile measurement system by utilizing two-elements ultrasonic transducer with both elements acting as transmitter and receiver. The aim is to obtain two-dimensional velocity information along measurement line and calculate the flow rate. We evaluate the transducer with sound pressure measurement and flow measurement. From the sound pressure measurement, there is one main lobe exist at the center between the elements due to the interference of both waves generated from each element. Therefore two-dimensional velocity measurement is possible. From the flow measurement, we can get two-dimensional velocity profile and calculate the flow rate. We compared the flow rate result with the flow rate reading from the electromagnetic flow meter, and we obtained the error of 4.98% for pipe flow and 10.43% for pipe flow under swirl effect with the measurement range from 8 mm to 50 mm. We used B-spline interpolation with Gaussian fitting to estimate the profile from range 0 mm to 8 mm and finally we were able to obtain full vector profile.
Increasing the coverage rate of ultrasonic path to flow field is helpful to improve measurement results’ accuracy of transit-time ultrasonic flowmeters while asymmetric flow or turbulence exists. In this paper, a 3D isosceles triangular ultrasonic path is presented considering the width of the ultrasonic signal and the maximum coverage rate of the ultrasonic path to flow field. To evaluate the feasibility and effectiveness of the path proposed, computational fluid dynamics simulations of three pipeline configurations, including straight pipeline, single elbow, and contracted pipeline upstream ultrasonic flowmeter (diameter of pipeline, , , or long are performed. In particular, inlet velocity of flow ranges from 0.1 to 10 m/s. Meanwhile, control simulation of U-type ultrasonic path is discussed to verify the effect of coverage rate of ultrasonic path to flow field on measurement results. It is shown that the proposed 3D isosceles triangular ultrasonic path, whose coverage rate is 54%, does well in improving the stability and accuracy of measurement results while pipeline configuration upstream flowmeter changes.
