Design Of Flowmeter Research Articles

Application of computational fluid dynamics and laser Doppler velocimetry to liquid ultrasonic flow meter design

Axisymmetric computational fluid dynamic (CFD) studies have been undertaken for the case of a coaxial, ultrasonic transducer housing in a cylindrical cross-section metering duct and compared to experimental results taken by laser Doppler velocimetry. Results are presented for a meter geometry having a single strut attachment of the transducer housing to the duct wall at Reynolds numbers (based on mean velocity and meter duct diameter) of 750, 3000 and 8000. Good matches between experiment and CFD modelling have been obtained near the duct walls, with some significant departures near the duct centreline, attributed to the limitations of modelling a 3D flow using an axisymmetric model. This CFD modelling is being used to improve the design of similar flow meters.

Downhole Fiber-Optic Flowmeter: Design, Operating Principle, Testing, and Field Installations

SummaryThis paper discusses the design, operating principles, flow-loop testing, and initial field installations of the world's first all-fiberoptic flowmeter for downhole deployment. The flowmeter provides real-time measurement of the flow rate, phase fraction, pressure, and temperature. It is deployed with the production tubing and is rated to 125°C and 15,000 psi. It is fullbore, nonintrusive, electrically passive, has no moving parts, and overcomes the design limitations imposed by downhole environments. Thus, it has the potential to provide highly reliable downhole measurements. The flowmeter has been tested extensively in industrial flow loops in a wide range of conditions. Results from the testing have demonstrated the flowmeter's ability to measure flow rates and water fractions in oil/water systems to within ±5% for the entire range of water cuts. These results have been validated by data from several field deployments.

터빈유량계의 3차원 유동에 관한 수치적 연구

Flow through a turbine flow meter is simulated by solving the incompressible Navier-Stokes equations. The solution method is based on the pseudo-compressibility approach and uses an implicit-upwind differencing scheme together with the Gauss-Seidel line relaxation method. The equations are solved steadily in rotating reference frames, and the centrifugal force and the Coriolis force are added to the equation of motion. The standard k-εmodel is employed to evaluate turbulent viscosity. Computational results yield quantitative as well as qualitative information on the design of turbine flow meters by showing the distributions of pressure and velocity around the turbine blades.

Small Gas Flow Measurement - Microcomputer Application in Education

This paper is focused on education in the field of small gas flow measurement. Students obtain theoretical knowledge in flow and they acquaint with different types of flowmeters. The Department of Automatic Control of Tomas Bata University is equipped with the thermal mass flowmeter (time - of - flight sensor). The theoretical education is on a basis of the mathematical model of energy and temperature balance simulated in the FEMLAB. Students use various constructional materials for design of the thermal mass flowmeter and they verify the properties of designed flowmeter on laboratory models.

Problems in the theory and design of electromagnetic flowmeters for dielectric liquids. Part 3a. Modelling of zero drift due to flux linkage between coil and electrode cables

This paper investigates theoretically the magnitudes of zero offsets and zero drifts originating from magnetic flux linkage between the coils of the electromagnet and the loop formed by the electrode cables in an electromagnetic flowmeter for dielectric liquids. The dependence of such zero offsets on liquid properties, frequency of operation, etc. is explained. The paper gives the results of measurements of the effective electrical conductivity and permittivity of dielectric liquids BP180 and Castrol OX-9 (and mixtures of these) in the frequency range 1 Hz–1 kHz. These are used to predict the zero offsets expected in metering these liquids using phase sensitive detection with the flowmeter tube described in Part 1 of the paper. Precautions needed in flowmeter design to minimise instrument zero offsets and zero drifts are explained. The electromagnetic flowmeter theory was developed at Cranfield and the determination of the electrical properties of the dielectric liquids was carried out at QinetiQ.

Low-cost thermal Σ-Δ air flow sensor

This paper describes the design and optimization of a hot-wire air flowmeter. A low-cost design of the packaging allows good thermal contact with the airflow, as well as good thermal isolation between the hot and cold points. It is a compact solution which allows easy PCB mounting and adaptation to standard-size small air pipes. The design has been optimized for low-cost applications. The sensor is read out by a thermal sigma-delta modulator. The dynamic range of this modulator has been extended by adding a constant power offset to its output. The fractal nature of the modulator response at low-clock frequencies is also experimentally shown.

Problems in the theory and design of electromagnetic flowmeters for dielectric liquids: Part 1: experimental assessment of static charge noise levels and signal-to-noise ratios

This paper reports on experimental measurements of electrode signal noise spectra in an electromagnetic flowmeter designed for flow measurement of the dielectric liquid BP180. The design of the flowmeter tube and the detection electronics is described. Dependence of the noise spectra on flow rate, electrode dimensions and particle content of the liquid is reported. Implications for flowmeter tube design and for the choice of frequency of operation to achieve reasonable signal-to-noise ratios are explained.

Problems in the theory and design of electromagnetic flowmeters for dielectric liquids. Part 2a: Theory of noise generation by turbulence modulation of the diffuse ionic charge layer near the pipe wall

This paper describes an analytical model of the generation of noise by turbulence modulation of the background charge distribution in electromagnetic flowmeters working with dielectric liquids. The model is tested for the highly insulating oil BP180 in cases with different flow speeds and electrode lengths, and the results show good agreement with the available experimental data. Comparison of experimental results of filtered and unfiltered oil shows that turbulence modulation of the background charge is responsible for the generation of noise in the filtered case, and that other source of noise is present in the unfiltered case. This model is therefore valid for clean fluids, and can be used to study the characteristics of the noise spectrum of a particular meter design under this condition.

Problems in the theory and design of electromagnetic flowmeters for dielectric liquids. Part 2b: theory of noise generation by charged particles

This paper describes an analytical model of the generation of noise by charged particles in electromagnetic flowmeters working with dielectric fluids. Using estimated charge values for the particles, the model predicts that particle noise dominates in the case of dirty liquids, with very small particle concentrations producing high levels of noise. Validation of the theory is done by comparison with available experimental data of noise in BP 180 oil for different flow rates and electrode lengths. The model can be used to study the noise spectrum of a particular meter design when the liquid and particle physical properties are known.

Design and development of thermal mass flowmeters for high pressure applications

This paper discusses the design and development of two thermal mass by-pass flowmeters for the ranges of 90 grams per second(g/s) and 15g/s operating at 18 bar and 19.5 bar pressures respectively for air flow measurement.

An Approach to the Design and Fabrication of a Microprocessor based Flow Meter using Resistance and Semiconductor Probe

An approach to the design and fabrication of a mass flow meter of a fluid using heat transfer technology is presented. The method uses the application of a simple matched pair of transistors as the flow transducer and compares the results with another flow transducer using a platinum resistance temperature detector. The effect of the temperature of the fluid is eliminated using the bridge circuit with the reference temperature probe placed in the static reference bath within the flow meter. The experimental results conform to the theoretical analysis that the bridge output follows the mass flow rate linearly if the flow is stream line. The effect of turbulence makes the output nonlinear. However a low cost microprocessor is used to linearise the flow data and display the flow value in digital form. The method used is a low cost one and is experimentally tested for flowing water at room temperature.

A Numerical Study on Faraday-Type Electromagnetic Flowmeter in Liquid Metal System, (II) Analysis of End Effect due to Saddle-Shaped Small-Sized Magnets with FALCON Code

In the design of the electromagnetic flowmeter (EMF) in the main cooling loop of the Japanese Prototype Fast Breeder Reactor “MONJU”, large-sized flat permanent magnet was adopted in order to make the end effect of the magnet as small as possible. For an EMF of a future large LMFBR, it is difficult to adopt such a large-sized magnet because of problems of a large space requirement and a tolerance against earthquake. Therefore, it is necessary to develop a novel EMF with small-sized magnets. It has been feared that the decrease of magnetic field and the end effect make the EMF's performance worse, but we have no detailed information about the end effect due to such small-sized magnets. By using the three-dimensional steady- state electromagnetic analysis code FALCON, we have studied numerically on the end effect of an EMF with saddle-shaped permanent magnets, the size of which is smaller than the pipe diameter. Consequently, it has been clarified that the performance of an EMF can be improved by utilizing the effect of the downstream end of magnets and by combining the inclined-electrodes and the effect of circumferential ends of magnets.

Ultrasonic transit-time flowmeters modelled with theoretical velocityprofiles: methodology

Fully developed flow is well defined for most values of Reynoldsnumber but distorted flow is not. Velocity profile is the definition given tothe distribution of velocity in the axial direction over the cross-section ofthe pipe. This distribution is not usually uniform and can vary dramaticallydepending on the properties of the fluid and the configuration of the pipe inwhich it flows. Ultrasonic flowmeters are affected by such distortions in theflow profile, often resulting in erroneous measurements. Transit-timeultrasonic flowmeters are widely used in industry in distorted fluid flows,therefore correction to or prediction of distorted profiles has sparked greatinterest in the design and application of ultrasonic flowmeters. This documentdescribes a method for modelling and analysing the effect of theoreticalasymmetric flow profiles on ultrasonic flowmeters of the transit-time type,thus allowing an understanding of installation effects.

New design of the two-phase flowmeters

This paper is concerned with a new mass method of measurement of small flow of two-phase media, where the solid particles are carried by a carrying gas (air). The method exploits the fact that the solid particles being carried by a flowing air impacting a properly formed obstacle generates an acoustic surface wave (acoustic emission). The acoustic signal is indicated by the aid of a high sensitive transducer, which converts the acoustic signal to an electric one. The magnitude of the electric signal is proportional to the (average) mass of particles having a constant (unified) velocity. In general, in this way we get the information about the magnitude of particles being measured and about their quantity. The electric output signal of the transducer is processed in the electric section of the meter, using up-to-date electrical devices that are able to carry out amplitude or frequency analyses of the signal and performs its another processing. We may use the same idea of the particle sensing, but with two obstacles in the flow channel, to create a cross-correlation velocity flowmeter.

Design of an electromagnetic flowmeter for insulating liquids

A measure of the suitability of an electromagnetic flowmeter for general applications is its electrical conductivity range. At the moment, the minimum value of electrical conductivity required in the application of an electromagnetic flowmeter is that of deionized water . A design description and results of experiments carried out on an electromagnetic flowmeter designed for use with insulating liquids or liquids with are presented. The flowmeter design is based on capacitive-type electrodes. The choice of magnetic field frequency and the design of the electrostatic shield is critical for the function of the flowmeter. A generic expression for estimation of the flow signal of a capacitive pick-up-type electromagnetic flowmeter is derived. The results of the experiments show that the electromagnetic flowmeter cannot only be used to measure the flow rate of dielectric liquids, but can also be used as a universal liquid flowmeter.

カルマン渦流量計の渦発生体形状の最適化と不確かさの算出法に関する研究

A vortex shedding flowmeter is widely used for measurements of various fluids in many fields of industry because of its numerous advantages, such as wide rangeability, long term reliability and low maintenance cost. Today, vortex flowmeters of various designs are manufactured by many companies in the world although the flowmeter design is not specified in the present industrial standards. The research project presented in this paper consists of a series of experimental studies and its objective is to develop a new design of a vortex shedding flowmeter, which can be used without any calibration using the actual fluid. This paper describes the first result of the project, i.e. optimization of the flowmeter design and determination of the measurement uncertainty. First, four of the bluff body dimensions were selected and optimized through series of systematic experiments so that the Strouhal number was least dependent on the Reynolds number. Next, the optimized design has been applied to flowmeters with inner diameters from 100mm to 400mm. These flowmeters were calibrated and the Strouhal number was precisely determined. Finally, a new method to calculate the uncertainty of the Strouhal number from the dimensional deviations of the parts of the flowmeter was developed experimentally and analytically. This project has been carried out by National Research Laboratory of Metrology and 10 collaborating companies in Japan. The results shown in this report are obviously very important for future standardization of a vortex flowmeter and for improvement of the accuracy in flow measurement in the world.

Discussion on Improved Design of a Proportional Flow Meter

Discussion on Improved Design of a Proportional Flow Meter

Author's Reply on the Discussion of the paper Improved Design of a Proportional Flow Meter

Author's Reply on the Discussion of the paper Improved Design of a Proportional Flow Meter

Fiber-optic Fabry-Perot flow sensor

A new design of a vortex-shedding flowmeter with a fiber-optic Fabry–Perot interferometer (FFPI) as the sensing element is described here to measure the liquid flow velocity in a pipe. The flow velocity is determined by measuring the frequency at which the reflected optical power from the FFPI is modulated. Experimentally, a linear dependence of optical modulation frequency on flow velocity is observed over the range from 0.14 to 3.0 m/s, in good agreement with theoretical prediction. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 18: 209–211, 1998.

Electromagnetic microprocessor-based flow-meters, counterflowmeters, and calorimeters for large-diameter pipes

This article examines the design and specifications of different flowmeters for large-diameter pipes.