Performance Of Flowmeter Research Articles

Study on the design and performance of a bi-directional cone flowmeter

The present study explores a novel design of cone flowmeter for bi-directional flow metering application. Two identical cone shapes are machined with their base circle surfaces joined together with a small step in between them and differential pressure measurement is done across the apex of the cones. The bi-directional cone flowmeter is tested under fully developed flow conditions and its performance under double 90° bend (out-of-plane) is also evaluated. The bi-directional cone flowmeter is tested in a circular pipe (inside diameter of 101mm) with water as the working medium for the flow Reynolds number ranging from 1.18×105 to 5.48×105. Influence of the half cone angle (α) and the location of static pressure taps on the coefficient of discharge (Cd) of a cone flowmeter are studied. Two cones with half cone angles α=30° and α=45° with a constant constriction ratio (β) of 0.75 are studied. Static pressure taps are located on both sides of the bi-directional cone. Two sets of locations of static pressure taps are studied. First set includes two static pressure taps on the pipe wall in the planes of apexes of the bi-directional cone—called apex taps. Second set includes pressure taps on the pipe wall in the planes at a distance D/4 away from the apexes of the bi-directional cone—called D/4 taps. Double 90° bend (out-of-plane) is placed at 1.5D, 5.5D, 9.5D and 13.5D upstream to the bi-directional cone flowmeter. It is observed that the apex static pressure taps located in the plane of apexes of the bi-directional cone result in statistically consistent coefficient of discharge for all Reynolds numbers covered in this study. The results suggest that the bi-directional cone flowmeter is insensitive to the swirl created by double 90° bend (out-of-plane) placed at the upstream of cone flowmeter, if placed at a distance of 9.5D or more.

Isentropic acoustic propagation in a viscous fluid with uniform circular pipeline flow

Isentropic wave propagation in a viscous fluid with a uniform mean flow confined by a rigid-walled circular pipeline is considered. A method based on the Fourier-Bessel theory, which is complete and orthogonal in Lebesgue space, is introduced to solve the convected acoustic equations. After validating the method's convergence, the cut-off frequency of wave modes is addressed. Furthermore, the effect of flow profile on wave attenuation is analyzed. Meanwhile, measurement performance of an ultrasonic flow meter based on wave propagation is numerically accounted.

Ultrasonic wave propagation in thermoviscous moving fluid confined by heating pipeline and flow measurement performance

Ultrasonic wave propagation in thermoviscous fluid with pipeline shear mean flow in the presence of a temperature gradient is investigated. On the assumption of irrotational and axisymmetric wave propagation, a mathematical formulation of the convected wave equation is proposed without simplification in the manner of Zwikker and Kosten. A method based on the Fourier-Bessel theory, which is complete and orthogonal in Lebesgue space, is introduced to convert the wave equations into homogeneous algebraic equations. Then numerical calculation of the axial wavenumber is presented. In the end, wave attenuation in laminar and turbulent flow is numerically studied. Meanwhile measurement performance of an ultrasonic flow meter is parametrically analyzed.

The Study of Detection System of Two-Wire Flowmeter Based on Virtual Instrument Technology

In order to test the performance of the two-wire flowmeter, the detection system based on virtual instrument technology is designed in this paper. This system mainly consists of four parts: master control unit, flow rate signal measurement unite, standard instrument and Measured instrument.The master control unit of the detection system is PC. With the communication protocol of MODBUS, PC control the detection device to synchronous sample the standard flow meter and the measured flow meter, and output 4 ~ 20mA current signal. The test analysis software is developed in LabWindows/CVI programming environment to achieve the test data automatically generated. Practice has proved that the system operation is simple, fast, and efficiency.

Analysis of viscosity effect on turbine flowmeter performance based on experiments and CFD simulations

Viscosity effect is one important factor that affects the performance of turbine flowmeter. The fluid dynamics mechanism of the viscosity effect on turbine flowmeter performance is still not fully understood. In this study, the curves of meter factor and linearity error of the turbine flowmeter changing with fluid viscosity variations were obtained from multi-viscosity experiments (the viscosity range covered is 1.0×10–6m2/s–112×10–6m2/s). The results indicate that the average meter factor of turbine flowmeter decreases with viscosity increases, while the linearity error increases. Furthermore, Computational Fluid Dynamics (CFD) simulation was carried out to analyze three-dimensional internal flow fields of turbine flowmeter. It was demonstrated that viscosity changes lead to changes of the wake flow behind the upstream flow conditioner blade and the flow velocity profile before fluid entering turbine rotor blade, which affect the distribution of pressure on the rotor blades, so impact the turbine flowmeter performance.

A method based on a novel flow pattern model for the flow adaptability study of ultrasonic flowmeter

Ultrasonic flowmeters are widely used in industry for accurate measurement. Flow adaptabilities of meters in non-ideal flow fields are usually concerned about by researchers. This paper presents a theoretical analysis method to study the measurement performance of ultrasonic flowmeter. For the specific water flow in single elbow pipe, a novel three-dimensional flow pattern model is invented by the trust region Newton algorithm based on computational fluid dynamics simulation results. In order to verify the correctness of the model, a typical ultrasonic flowmeter with single diametric acoustic path is mainly analyzed. By comparing flow adaptabilities of the meter downstream of the single elbow with both the novel theoretic model analysis approach and simulation method, good agreement is achieved. It is indicated that both the three-dimensional model and its invention method are valid for this study, which is not only helpful to get knowledge of characteristics of disturbed flows, but also provides a practical method to study the flow adaptability of ultrasonic flowmeter in non-ideal flow fields.

Frequency detection in vortex flowmeter for low Reynolds number using piezoelectric sensor and installation effects

Piezoelectric sensors are one of the most widely used sensors for vortex flowmeter application due to their low cost. Various researchers have employed piezoelectric sensor for this application. However, the location of the sensor and the performance of vortex flowmeter under disturbed conditions are seldom reported. In the present study, experimental investigations are conducted with water as the working medium in a circular pipe of diameter 52.5mm. The optimum position of the piezoelectric sensor behind the trapezoidal bluff body is found out be 0.85 times the width of the bluff body. A new algorithm based on empirical mode decomposition and autocorrelation decay rate is suggested to identify the vortex shedding frequency under low Reynolds numbers flow condition. The performance of the flowmeter is also evaluated under different disturbed flow conditions to quantify the sensitivity of the flowmeter. The disturbances studied are single 90° bend, gate valve, globe valve, and two 90° out of plane bends. The overall uncertainty in the Strouhal number is within ±1.71%.

Experimental study on dynamic performance of coriolis mass flow meter and compensation technology

The Coriolis mass flow meter, for its features of directly measuring mass flow and high precision, is widely utilized in the flow measuring fields like batch filling and commercial trade. However, the unsatisfactory dynamic performance is one major constraint to Coriolis mass flow meter from being even more widely used in batch filling industry. To solve the problem, an experimental system which generates refined flow step stimulus signals for Coriolis mass flow meter was designed and based on which experimental and theoretical study on dynamic performances of typical Coriolis mass flow meter was carried out. On top of this, a time-domain recursive digital filter was designed to provide dynamic compensation and the experiments showed this filter can reduce the step response time of Coriolis mass flow meter by about 50%.

Effects of free convection and friction on heat-pulse flowmeter measurement

► A well-designed system was set up to test performance of heat-pulse flowmeter. ► Measurement error at low flow velocities resulted primarily from free convection. ► Turbulence causes a loss of accuracy and precision at high flow velocities. ► An empirical formula was developed for calibrating measured velocities. ► Improved characterization of the vertical profile of hydraulic conductivity. Heat-pulse flowmeter can be used to measure low flow velocities in a borehole; however, bias in the results due to measurement error is often encountered. A carefully designed water circulation system was established in the laboratory to evaluate the accuracy and precision of flow velocity measured by heat-pulse flowmeter in various conditions. Test results indicated that the coefficient of variation for repeated measurements, ranging from 0.4% to 5.8%, tends to increase with flow velocity. The measurement error increases from 4.6% to 94.4% as the average flow velocity decreases from 1.37 cm/s to 0.18 cm/s. We found that the error resulted primarily from free convection and frictional loss. Free convection plays an important role in heat transport at low flow velocities. Frictional effect varies with the position of measurement and geometric shape of the inlet and flow-through cell of the flowmeter. Based on the laboratory test data, a calibration equation for the measured flow velocity was derived by the least-squares regression analysis. When the flowmeter is used with a diverter, the range of measured flow velocity can be extended, but the measurement error and the coefficient of variation due to friction increase significantly. At higher velocities under turbulent flow conditions, the measurement error is greater than 100%. Our laboratory experimental results suggested that, to avoid a large error, the heat-pulse flowmeter measurement is better conducted in laminar flow and the effect of free convection should be eliminated at any flow velocities. Field measurement of the vertical flow velocity using the heat-pulse flowmeter was tested in a monitoring well. The calibration of measured velocities not only improved the contrast in hydraulic conductivity between permeable and less permeable layers, but also corrected the inconsistency between the pumping rate and the measured flow rate. We identified two highly permeable sections where the horizontal hydraulic conductivity is 3.7–6.4 times of the equivalent hydraulic conductivity obtained from the pumping test. The field test results indicated that, with a proper calibration, the flowmeter measurement is capable of characterizing the vertical distribution of preferential flow or hydraulic conductivity.

유한요소법을 이용한 고온용 초음파 유량센서의 설계 및 평가

An operation temperature of Pb(Zr,Ti)O3 based piezoelectric ultrasonic flowmeter was generally restricted to below 200˚C due to a low depoling temperature of its ceramic material. Thus, a new designed piezoelectric ultrasonic flowmeter was fabricated in order to protect from the extremely hot fluid. Its structure is optimized by a finite element method to effectively stop heat flowing along a waveguide. Various materials such as Cu, Al, SUS were examined as a multi-plate radiation shield to enhance the performance of piezoelectric ultrasonic flowmeter. The SUS was evaluated as the most effective material to enhance the performance of piezoelectric ultrasonic flowmeter. As the number of plates of the radiation shield increased, the temperature at piezoelectric transducer away from the hot fluid was constantly decreased with a ratio of 3.12˚C per the plate number.

3-D Numerical Simulation and Analysis on V-Cone Flowmeter Based on LES Method

The rear pressure measurement position of V-cone flowmeter is in the complex vortex structure area after fluid around the cone. The non-uniformity of the fluid field will influence the measurement precision of V-cone flowmeter. Large eddy simulation (LES) has been used to study the V-cone flowmeter’s 3-D flow field structure with different Reynolds number in this paper. The better fluid area information can gain by this way. The results show that the values of discharge coefficient (Cd) obtained from LES are more close to the experiment data than the values obtained from k-ε model. Different turbulence intensity with different Reynolds number effects the velocity distribution in the V-cone flowmeter’s flow field. When Reynolds number equals to 20000, the flow field within 8d distance from V-cone tail should keep from being disturbed while the flowmeter under working condition. The non-interfering distance from V-cone tail flow field increases with the Reynolds number raising. These analysis results can offer optimizational information for V-cone flowmeter performance and testing method improvement.

Experiment and Numerical Simulation Study on the Viscosity Impact of Turbine Flowmeter's Performance

Turbine flow meter is a very significant measuring instrument. As an important flow meter, turbine meter is widely used in many fields for its high accuracy, good repeatability, small size and light weight. However, with the viscosity of the measurement fluid increasing, the measured variation of the linearity becomes bad, which makes great influence on the meter factor. In this paper, the experiment on the viscosity impact of turbine flowmeter's performance was completed by adjusting the temperature of the mixture of diesel and lubricants, i.e. changing medium viscosity. And the methods of computational fluid dynamics (CFD) numerical simulate were used to research the accuracy of the turbine flow meter in the same conditions. According to the comparison of the two methods, the influence of the turbine flowmeter’s precision measuring fluids with different viscosities was analyzed. It provides a data basement for improving the measurement accuracy of a certain viscosity fluid in the future.

Influence of blockage and shape of a bluff body on the performance of vortex flowmeter with wall pressure measurement

Experimental and numerical investigations are carried out with various bluff body shapes to identify an appropriate shape which can be used for vortex flowmeter application. In both the cases vortex shedding frequency is inferred from the fluctuation of wall pressure. The numerical simulations are carried out with cylindrical and triangular bluff bodies to understand the vortex shedding phenomenon and to identify an appropriate turbulence model for this class of flows with wall pressure measurement. The simulations reveal that the k– ε RNG model predicts the Strouhal number closer to the experimental results than other models. The experimental investigations are carried out with several bluff body shapes, such as triangular, trapezoidal, conical, cylindrical and ring shapes, with water as the working medium. In this context, the effects of sampling rate, tap location and blockage effects are explored. The results suggest that the axisymmetric tapping is better than differential pressure tapping in terms of signal amplitude. The non-dimensional location of the static pressure tap is found to be 0.714 times diameter of pipe times blockage. The trapezoidal bluff body is found to be the best among all the bluff bodies investigated in terms of signal amplitude and constancy of Strouhal number. The vortex flowmeter performance is also measured under disturbed flow conditions created by using gate valve and bends. These results are significant because they provide an optimum bluff body shape and blockage, and also present the performance of vortex flow meter under disturbed flow conditions which is rather seldom reported in the literature.

A New Approach to Laminar Flowmeters

After studying the performance and characteristics of actual laminar flowmeters a new disposition for this type of sensors is proposed in such a way that the measurement errors introduced by the intrinsic nature of the device can be minimized. The preliminary study shows that the developing entry region introduces non-linearity effects in all these devices. These effects bring about not only errors, but also a change in the slope of the linear calibration respect of the Poiseuille relation. After a subsequent analysis on how these non-linearity errors can be reduced, a new disposition of this type of flowmeters is introduced. This device makes used of flow elements having pressure taps at three locations along its length and connected to three isolated chambers. In this way, the static pressure can be measured at three locations and contributed to by the pressure taps at the level of each chamber. Thus the linearization error is reduced with an additional advantage of producing a reduced pressure drop.

Influence of blockage and upstream disturbances on the performance of a vortex flowmeter with a trapezoidal bluff body

Experimental investigations are conducted on vortex flowmeter with the differential wall pressure measurement method. The bluff body employed is trapezoidal in shape and water is used as the working fluid. Three different blockages (0.14, 0.24 and 0.3) are considered in this study. The performance of the vortex flowmeter is studied both under fully developed condition and in the presence of flow disturbances. The flow disturbance is created using 45° swirl generator and gate valve placed at different upstream distances. The performance of the flowmeter is also evaluated in the presence of a Laws Vanes flow conditioner placed downstream of the swirl generator. The blockage ratio of 0.3 is found to be the best among all the blockages studied under both disturbed and undisturbed conditions.

CFD prediction of the effects of the upstream elbow fittings on the performance of cone flowmeters

This paper describes the numerical studies to establish the effect of upstream elbow fittings on the performance of the cone flowmeter. Different combinations of elbows were installed upstream of the cone at a distance of 4D to study their effect on the discharge coefficient of the cone flowmeter. The computational fluid dynamics (CFD) simulations have been conducted with an RNG k – ε turbulence model for three equivalent diameter ratios of the cone flowmeter over a wide range of Reynolds numbers. The elbow fittings have a marginal effect on the discharge coefficients ( C d ) of the cone flowmeters even at very high Reynolds numbers ( Re ∼ O ( 10 6 ) ) . The variation in the discharge coefficients is small (±2%). In addition, the variation in the predicted values of the C d over a wide range of Reynolds numbers is also very small (<1%). The distorted velocity profile due to the elbow fitting at the upstream of the cone is slightly improved in the presence of the cone. The intensity of secondary flows also reduces due to the imposed backflow pressure by the cone. The pressure drop coefficient of the cone flowmeter reduces as 1 / β 4 , and it is independent of the Reynolds number at higher values.

OIL-WATER TWO-PHASE FLOW MEASUREMENT USING A VENTURI METER AND AN OVAL GEAR FLOW METER

The performance of a hybrid flow meter for the measurement of oil-water two-phase flow rates is investigated. The hybrid flow meter consists of a venturi meter and an oval gear flow meter. Experimental investigations were undertaken on horizontal pipelines of 15 mm, 25 mm, and 40 mm diameters on an oil-water two-phase flow loop. The total flow rate of the oil-water two-phase flow is in the range of 1.2 ∼ 5.5 m3/h, while the oil volume fraction varies from 0 to 100%. The research verifies that the hybrid flow meter is feasible for oil-water two-phase flow measurement and the accuracy of the hybrid flow meter is satisfactory. Experimental results also indicate that the oil fraction has a significant impact on the selection of the meter coefficient of the venturi and hence the measurement results of density and total mass flow rate.

MEASUREMENT OF THE FLOW RATE AND VOLUME VOID FRACTION OF GAS-LIQUID BUBBLE FLOW USING A VORTEX FLOW METER

Measurement of flow rate and volume void fraction by means of a conventional meter plays an important role in the development of measurement techniques for multiphase flow parameters. Owing to its advantage in insensitivity to most physical properties of the fluid-like viscosity and density, a vortex flow meter was used to measure the flow rate and volume void fraction of gas-liquid bubble flows in this study. The performance of the vortex flow meter under such flow conditions was investigated. First, regular Karman vortex shedding was found in bubble flows with less than 30% volume void fraction, but its stability was influenced by the introduction of a gas-phase component. Second, the frequency of the bubble vortex shedding was approximately in linear proportion to the two-phase Reynolds number, whereas the volume void fraction had little impact on the frequency. Third, the amplitude of the bubble vortex signal could be expressed as a power function format. Moreover, when the volume void fraction was in the range 0–25.90% and Reynolds number between 9.47 × 104 and 20.44 × 104, the meter coefficient of the vortex flow meter was kept constant. Correlations between the vortex shedding characteristics and two-phase flow parameters were established based on mathematical modeling and experimental calibrations. Finally, the two-phase mixture flow rate and the volume void fraction were obtained from the proposed correlations. These findings provide a possibility of using only a single vortex flow meter to measure double parameters in gas-liquid bubble flows.

Application of empirical mode decomposition based energy ratio to vortex flowmeter state diagnosis

To improve the measurement performance, a method for diagnosing the state of vortex flowmeter under various flow conditions was presented. The raw sensor signal of the vortex flowmeter was adaptively decomposed into intrinsic mode functions using the empirical mode decomposition approach. Based on the empirical mode decomposition results, the energy of each intrinsic mode function was extracted, and the vortex energy ratio was proposed to analyze how the perturbation in the flow affected the measurement performance of the vortex flowmeter. The relationship between the vortex energy ratio of the signal and the flow condition was established. The results show that the vortex energy ratio is sensitive to the flow condition and ideal for the characterization of the vortex flowmeter signal. Moreover, the vortex energy ratio under normal flow condition is greater than 80%, which can be adopted as an indicator to diagnose the state of a vortex flowmeter.

Study on the effect of vertex angle and upstream swirl on the performance characteristics of cone flowmeter using CFD

Computational Fluid Dynamics (CFD) has emerged as a revolutionary tool for optimizing the design of any flowmeter for given conditions. The flow features obtained with CFD are more extensive compared to experiments. In the present study, CFD code ‘FLUENT” after validation has been used to investigate the effect of cone vertex angle and upstream swirl on the performance of cone flowmeter. The values of discharge coefficient ( C d ) evaluated for different vertex angles shows that the value of discharge coefficient is independent of Reynolds number and its value decreases with increase in vertex angle. In the presence of upstream disturbance in the form of swirl, the value of discharge coefficient is also independent of Reynolds number and its value is only marginally affected by the magnitude of swirl. The flow in a longitudinal plane shows the presence of a pair of contra-rotating vortices in the recirculation region just downstream of the cone. The velocity profile downstream becomes stable after a distance of about 5D.