The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
C Clark - One of the best experts on this subject based on the ideXlab platform.
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prediction of the dynamic performance of fast response Coriolis Meter systems
IEEE Transactions on Instrumentation and Measurement, 2008Co-Authors: C Clark, R Cheesewrigh, Shiwe WangAbstract:There is a clear need for Coriolis Meters with better dynamic response characteristics than those currently available. There are a number of factors that affect the dynamic response. These factors arise both from the basic mechanical design of the Meter, from the design of drive and control mechanisms, and from the design of the signal processing used to extract the Meter output. All these factors are considered, and it is shown how finite element modeling can be used to give predictions of the response.
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the performance characteristics of a micro machined Coriolis flow Meter an evaluation by simulation
Flow Measurement and Instrumentation, 2006Co-Authors: C Clark, S Wang, R CheesewrighAbstract:Abstract Micro-machined Coriolis Meters will enable measurement of very low flow rates (0.1–500 g/h) and, potentially, ultra-low flows (0.1–100 mg/h). Application areas include the delivery of medical drug infusions to patients, and a wide variety of micro-fluidic devices. An evaluation of the performance of two prototype micro-machined flow-tubes of differing shapes is reported, based upon results obtained from a virtual Coriolis Meter. This tool comprises a finite element modelling capability which simulates the Meter flow-tube in motion, with the flow represented simply as a continuous string, i.e. 1-dimensional and frictionless, and the model allows the generation of pseudo-data at points on the tube corresponding to sensor locations. Application of signal processing algorithms then enables the representation of an indicated flow time history output by a Coriolis Meter in response to a prescribed input flow. Results indicate that the devices investigated were all highly linear and that Meter sensitivity is independent of fluid density. One flow-tube shape confers higher stiffness than the other and, for both tube shapes, increasing wall thickness increases tube stiffness at a greater rate than the tube mass. Higher stiffness results in reduced Meter sensitivity, but increased drive frequency (hence, faster dynamic response). The spatial averaging resulting from the use of ‘distributed’ internal sensors inevitably yields Meter sensitivity values that are lower than the potential maximum value that might be achieved by use of ‘point’ sensors; however there are practical reasons why this latter approach would not work. The dynamic response to a flow step is essentially the same as found for macro-Coriolis Meters.
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Virtual Coriolis flow Meter: a tool for simulation and design
2005Co-Authors: S Wang, C Clark, R CheesewrighAbstract:Abstract: A modelling tool has been developed, which has enabled significant new findings in relation to rapid dynamic response measurements of time-dependent flows using Coriolis Meters. The tool comprises a finite element modelling capability that simulates the Meter flow tube in motion and allows the generation of pseudo-data at points on the tube correspond-ing to sensor locations. Combined with this, a suite of signal processing algorithms then enables the representation of an indicated flow time history output by a Coriolis Meter in response to a prescribed input flow. The aims were then to investigate Meter response to flow steps, ramps, and pulsations. Methods of increasing speed of response are of particular importance, for example, in fast batch-filling applications. Flow steps introduce one or more inevitable noise components in the Meter sensor signals, and modelling results suggest that for a given Meter geometry, the corresponding noise amplitude in the Meter-indicated flow is a constant fraction of the step height. The virtual Coriolis Meter has also demonstrated the potential for a substan-tial contribution toMeter design by enabling the development of newMeters with specifications matched to selected requirements to meet a wide range of applications
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the response of Coriolis flowMeters to pulsating flows
Flow Measurement and Instrumentation, 2004Co-Authors: R Cheesewright, C ClarkAbstract:Abstract Generally, current models of Coriolis flowMeters have a very limited dynamic response. This paper presents work which investigates the dynamic response of the Meter flow tube alone (i.e. by-passing the flow transmitter) to flow pulsations. Because the shortest time for which an estimate of the phase difference can be achieved appears to be the period of one drive cycle, pulsations at frequencies somewhat lower than the Meter drive frequency were investigated. Our existing signal processing algorithms were used to determine phase differences from sensor signals (or pseudo-signals) generated from three different sources: firstly, pseudo-data generated from our previously developed theoretical model of a straight tube Meter response to pulsations; secondly, pseudo-data produced by finite element simulations of flow tubes with complex geometries, following validation against the straight tube theoretical results; finally, experimental data obtained by recording the internal sensor signals from eight commercially available flowMeters. Results from these three sources showed a high degree of consistency and confirmed the capability of Meter flow tubes to reveal both the amplitude and reasonable definition of the waveform of flow pulsations. All Meters tested experimentally showed a significant component of sensor signal noise at the Coriolis frequency. The results indicate that with appropriate flow tube design and improved Meter drive and signal processing procedures, a high dynamic performance Coriolis Meter is achievable.
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the effect of flow pulsations on Coriolis mass flow Meters
Journal of Fluids and Structures, 1998Co-Authors: R Cheesewright, C ClarkAbstract:Abstract It has been reported that the accuracy of Coriolis mass flow Meters can be adversely affected by the presence of pulsations (at particular frequencies) in the flow. A full analysis of the transient performance of a commercial Coriolis Meter is only possible using finite element techniques. However, this is a transient, nonlinear problem in which the space and time variables are not (strictly) separable and the finite element techniques for tackling such problems make it desirable to have an analytical solution for a simplified Meter, against which the finite element solution can be compared. This paper reports such a solution. The solution will also provide guidance for experiments. Existing analytical solutions for the performance of Coriolis Meters in steady flow (a complex eigenvalue problem) are not easily extended to the transient flow case. The paper thus begins with the presentation of an alternative solution for steady flow through a simple, straight tube, Coriolis Meter and it is notable that this solution gives a simple analytical expression for the experimentally observed small change in the resonant frequency of the Meter, with flow rate, as well as an analytical expression for the Meter sensitivity. The analysis is extended to the transient case, using classical, forced vibration, modal decomposition techniques. The solution shows that, unlike the steady flow case where the detector signals contain components at the drive frequency and the second mode frequency (Coriolis frequency), for pulsatile flow the detector signals will in general contain components involving at least four frequencies. It is demonstrated that the Meter error depends on the algorithm used to estimate the phase difference from the detector signals. The particular flow pulsation frequencies which could possibly lead to large Meter errors are identified.
I Ajsic - One of the best experts on this subject based on the ideXlab platform.
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phase locking control of the Coriolis Meter s resonance frequency based on virtual instrumentation
Sensors and Actuators A-physical, 2003Co-Authors: J Kuti, Andrej Smrecnik, I AjsicAbstract:The Coriolis Meter is a resonant-type sensor that is used for measuring the mass flowrate and the density of fluids. Its regular operation is conditional on the resonance vibration of its measuring tube. This paper presents the characteristics of a resonance-control system that is based on maintaining the proper phase difference between the detection and the excitation signals (phase-locked loop (PLL)). The controller was realized as a virtual instrument and programmed in the LabVIEW environment, which was also used for performing the theoretical simulations.
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an analytical estimation of the Coriolis Meter s characteristics based on modal superposition
Flow Measurement and Instrumentation, 2002Co-Authors: J Kuti, I AjsicAbstract:Abstract The aim of this paper is to derive approximate, analytically expressed, theoretical characteristics for a straight, slender-tube Coriolis Meter, which can be applied to any of its working modes. The mathematical model is based on the theories of the Euler beam and one-dimensional fluid flow, and includes the effects of axial force, added masses, damping and excitation. The analytical approximations are evaluated by applying a Taylor-series expansion to the solutions of the Galerkin method, which are considered as a superposition of the Euler-beam modal functions. On the basis of the obtained analytical expressions, the properties of the Meter’s characteristics are discussed, with the emphasis being on particular nonidealities.
J Kuti - One of the best experts on this subject based on the ideXlab platform.
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phase locking control of the Coriolis Meter s resonance frequency based on virtual instrumentation
Sensors and Actuators A-physical, 2003Co-Authors: J Kuti, Andrej Smrecnik, I AjsicAbstract:The Coriolis Meter is a resonant-type sensor that is used for measuring the mass flowrate and the density of fluids. Its regular operation is conditional on the resonance vibration of its measuring tube. This paper presents the characteristics of a resonance-control system that is based on maintaining the proper phase difference between the detection and the excitation signals (phase-locked loop (PLL)). The controller was realized as a virtual instrument and programmed in the LabVIEW environment, which was also used for performing the theoretical simulations.
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an analytical estimation of the Coriolis Meter s characteristics based on modal superposition
Flow Measurement and Instrumentation, 2002Co-Authors: J Kuti, I AjsicAbstract:Abstract The aim of this paper is to derive approximate, analytically expressed, theoretical characteristics for a straight, slender-tube Coriolis Meter, which can be applied to any of its working modes. The mathematical model is based on the theories of the Euler beam and one-dimensional fluid flow, and includes the effects of axial force, added masses, damping and excitation. The analytical approximations are evaluated by applying a Taylor-series expansion to the solutions of the Galerkin method, which are considered as a superposition of the Euler-beam modal functions. On the basis of the obtained analytical expressions, the properties of the Meter’s characteristics are discussed, with the emphasis being on particular nonidealities.
Coli Clark - One of the best experts on this subject based on the ideXlab platform.
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the simulation of Coriolis Meter response to pulsating flow using a general purpose f e code
Journal of Fluids and Structures, 2000Co-Authors: A Elhadj, Robe Cheesewrigh, Coli ClarkAbstract:The publication of a theoretical analysis of the response of a simple straight-tube Coriolis Meter to flow pulsations raised the question of the extent to which the results of that analysis are generic over the wide range of geometric configurations used in commercially available Meters. A procedure for using a general purpose finite element (FE) code to investigate this question is presented. The dual time scales, which are an essential feature of pulsating flow through a Coriolis Meter, are used to minimize the amount of computation required to simulate the Meter response. The FE model is developed in a full 3-D form with shear deflection and axial forces, and the computation of the simulated response for the geometrically most complex Meter currently available shows that this level of representation is necessary to reveal the full details of the response. The response derived from the FE simulation for straight-tube Meters, is compared with the published theoretical response and to experimental data. Over a range of different Meters, the characteristics of the sensor signals in the presence of flow pulsations are shown to be generally similar. In all cases, the simulated sensor signals contain components corresponding to beating between the pulsation frequency and the Meter drive frequency, in addition to the main component at the drive frequency. Spectra are computed from the simulated Meter responses and these are used to show that the relationship between the mass flow rate and the phase difference between the component of the sensor signals at the drive frequency, is not significantly affected by the pulsations. Thus, the work suggests that the reports of changes in Meter calibration due to certain frequencies of flow pulsation represent errors in signal processing rather than fundamental changes in the Meter characteristics.
R Cheesewright - One of the best experts on this subject based on the ideXlab platform.
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the response of Coriolis flowMeters to pulsating flows
Flow Measurement and Instrumentation, 2004Co-Authors: R Cheesewright, C ClarkAbstract:Abstract Generally, current models of Coriolis flowMeters have a very limited dynamic response. This paper presents work which investigates the dynamic response of the Meter flow tube alone (i.e. by-passing the flow transmitter) to flow pulsations. Because the shortest time for which an estimate of the phase difference can be achieved appears to be the period of one drive cycle, pulsations at frequencies somewhat lower than the Meter drive frequency were investigated. Our existing signal processing algorithms were used to determine phase differences from sensor signals (or pseudo-signals) generated from three different sources: firstly, pseudo-data generated from our previously developed theoretical model of a straight tube Meter response to pulsations; secondly, pseudo-data produced by finite element simulations of flow tubes with complex geometries, following validation against the straight tube theoretical results; finally, experimental data obtained by recording the internal sensor signals from eight commercially available flowMeters. Results from these three sources showed a high degree of consistency and confirmed the capability of Meter flow tubes to reveal both the amplitude and reasonable definition of the waveform of flow pulsations. All Meters tested experimentally showed a significant component of sensor signal noise at the Coriolis frequency. The results indicate that with appropriate flow tube design and improved Meter drive and signal processing procedures, a high dynamic performance Coriolis Meter is achievable.
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the effect of flow pulsations on Coriolis mass flow Meters
Journal of Fluids and Structures, 1998Co-Authors: R Cheesewright, C ClarkAbstract:Abstract It has been reported that the accuracy of Coriolis mass flow Meters can be adversely affected by the presence of pulsations (at particular frequencies) in the flow. A full analysis of the transient performance of a commercial Coriolis Meter is only possible using finite element techniques. However, this is a transient, nonlinear problem in which the space and time variables are not (strictly) separable and the finite element techniques for tackling such problems make it desirable to have an analytical solution for a simplified Meter, against which the finite element solution can be compared. This paper reports such a solution. The solution will also provide guidance for experiments. Existing analytical solutions for the performance of Coriolis Meters in steady flow (a complex eigenvalue problem) are not easily extended to the transient flow case. The paper thus begins with the presentation of an alternative solution for steady flow through a simple, straight tube, Coriolis Meter and it is notable that this solution gives a simple analytical expression for the experimentally observed small change in the resonant frequency of the Meter, with flow rate, as well as an analytical expression for the Meter sensitivity. The analysis is extended to the transient case, using classical, forced vibration, modal decomposition techniques. The solution shows that, unlike the steady flow case where the detector signals contain components at the drive frequency and the second mode frequency (Coriolis frequency), for pulsatile flow the detector signals will in general contain components involving at least four frequencies. It is demonstrated that the Meter error depends on the algorithm used to estimate the phase difference from the detector signals. The particular flow pulsation frequencies which could possibly lead to large Meter errors are identified.