This book describes the basic principles of electromagnetic induction measurements and consolidates the outcomes of recent research. It encompasses pipeline electromagnetic flow meters, electromagnetic flow meters, multiphase flow electromagnetic flowmeters and flow field of electromagnetic induction reconstruction. Though theoretical in nature it does draw on experimental data and includes new research findings, especially in the areas of multiphase flow and flow reconstruction. With a focus on theory and computation in flow measurement by electromagnetic induction including traditional flowmeters in closed conduits, velocity probe, two-phase flow, velocity reconstruction and dry calibration it will be an invaluable resource for researchers and practising engineers. The book uses MATLAB(R) to introduce efficient numerical methods to model and simulate flows, sensor construction and geometry, and the effect of pipe materials.
Key Features
- A comprehensive review on all issues to do with EM flowmeters
- Includes latest research directions and findings
- Accompanying MATLAB(R) code
- A reference text for students, researchers, users and designers
- Industrial and commercial interest
Author(s): Xiao-Zhang Zhang
Series: IOP Series in Sensors and Sensor Systems
Publisher: IOP Publishing
Year: 2020
Language: English
Pages: 129
City: Bristol
PRELIMS.pdf
Foreword
Acknowledgements
Author biography
X-Z Zhang
Nomenclature
CH001.pdf
Chapter 1 History and development of theoretical research
References
CH002.pdf
Chapter 2 Basic equations and solution methods
2.1 Basic equations
2.2 Boundary conditions and methods of solutions
2.2.1 Virtual current
2.2.2 Magnetic field
2.2.3 Flow velocity
2.3 Summary
References
CH003.pdf
Chapter 3 Characteristics of EM flowmeters in closed conduits
3.1 Concepts and definitions
3.1.1 Rectilinear weight function
3.1.2 Axisymmetric weight function
3.1.3 Non-uniformity of weight function
3.1.4 Sensitivity of EM flowmeters
3.1.5 Symmetry of the magnetic field and electrode geometry
3.1.6 Uniform magnetic field
3.1.7 Weight function under 2D assumption
3.2 Effect of the electrode shape on the weight function
3.2.1 Point electrodes
3.2.2 Large contacting electrode
3.2.3 Contamination of large electrodes
3.2.4 Large non-contacting electrode
3.2.5 Optimum positions of two pairs of point electrodes
3.2.6 Effect of the conducting pipe connections
3.3 Effects of coil design on magnetic field
3.3.1 ‘Ideal magnet’ model and numerical computation
3.3.2 Magnetic field of coils with diamond shape
3.3.3 Calculation and measurement of a D500 EM flowmeter
3.3.4 Optimum coils design for another D500 EM flowmeter
3.4 Effect of flow velocity distribution
3.4.1 Rectilinear flow
3.4.2 Swirl flow
3.4.3 Partially filled flow
3.5 Asymmetry problems
3.5.1 Errors caused by electrode position and coil dimension
3.5.2 Developing flow
References
CH004.pdf
Chapter 4 Electromagnetic velocity probe
4.1 Introduction
4.2 Long cylinder probe parallel to flow
4.3 Calculation of the sensitivity of EM probes using a 3D model
4.3.1 Problem description
4.3.2 Calculation of virtual current
4.3.3 Virtual currents under other boundary conditions
4.4 Calculation of magnetic field
4.4.1 Single turn coil
4.4.2 Ferromagnetic wall
4.4.3 Real annular coil
4.5 Potential flow field around the probe
4.6 Sensitivity
4.7 Effect of pipe wall property on sensitivity
4.8 Other probe types
4.9 Conclusions
References
CH005.pdf
Chapter 5 Effect of two-phase flow
5.1 Introduction
5.2 Effect of gas bubble at various positions in a pipe cross section
5.3 Effect of gas bubble at various pipe axis positions
5.4 3D model for virtual current with a bubble
5.5 Effect of several bubbles
5.6 Other works
References
CH006.pdf
Chapter 6 Flow reconstruction
6.1 Introduction
6.2 Two methods for flow reconstruction
6.2.1 Geometry discretization
6.2.2 Spectrum expansion
6.3 Examples of reconstruction
6.3.1 Example of geometry discretization
6.3.2 Example of spectrum expansion
6.4 Discussion
References
CH007.pdf
Chapter 7 Dry calibration
7.1 Review of research history
7.2 Some examples
7.2.1 Based on field measurement
7.2.2 Based on transformer signal
7.2.3 Virtual current to help with ‘dry calibration’
7.3 Comments
References
APP1.pdf
Chapter
APP2.pdf
Chapter
APP3.pdf
Chapter
APP4.pdf
Chapter
APP5.pdf
Chapter
E.1 Weight function of EM flowmeters with one-pair or two-pairs of electrodes under uniform transverse field
E.2 Scale potential of magnetic field under various dimensions (rectangle coil)
E.3 Weight function under point electrode and ‘ideal magnet’
E.4 Effect of conductive pipe connection on the sensitivity of EM flowmeters
