Various developments in the use of electrical impedance methods in multiphase flow are reviewed. Because the components of a multiphase flow often exhibit different electrical properties, a variety of probes have been developed to study such flows by measuring impedance in the region of interest. Nonintrusive devices are used to measure spatially averaged flow properties, such as void fraction. Local probes have been developed to measure a variety of pointwise flow quantities, including film thickness in annular flow, local void fraction in dispersed flows, bubble and particle sizes, and flow velocities. Such impedance probes are usually easy to build and use, and can have a high frequency response. However, the spatial resolution of the probes may be limited, calibration may be difficult, and the accuracy of some probes may be limited to specific phase distributions. Researchers are now using electric fields to reconstruct the impedance distribution within a measurement volume via Electrical Impedance Tomography (EIT). EIT systems employ voltage and current measurements on the boundary of a domain to create a representation of the impedance distribution within the domain. EIT inversion algorithms are discussed, and the application of EIT to multiphase flows is reviewed. The benefits and limitations of EIT systems are also discussed.

1.
Abouelwafa
M. S. A.
, and
Kendall
E. J. M.
,
1980
, “
The Use of Capacitance Sensors for Phase Percentage Determination in Multiphase Pipelines
,”
IEEE Transactions on Instrumentation and Measurement
, Vol.
IM-29
, pp.
24
27
.
2.
Abuaf
N.
,
Feierabend
T. P.
,
Zimmer
G. A.
, and
Jones
O. C.
,
1979
, “
Radio-frequency Probe for Bubble Size and Velocity Measurements
,”
Review of Scientific Instruments
, Vol.
50
, pp.
1260
1263
.
3.
Andreussi
P.
,
Di Donfrancesco
A.
, and
Messia
M.
,
1988
, “
An Impedance Method for the Measurement of Liquid Hold-Up in Two-Phase Flow
,”
International Journal of Multiphase Flow
, Vol.
14
, pp.
777
785
.
4.
Andreussi
P.
, and
Bendiksen
K.
,
1989
, “
An Investigation of Void Fraction in Liquid Slugs for Horizontal and Inclined Gas-Liquid Pipe Flow
,”
International Journal of Multiphase Flow
, Vol.
15
, pp.
937
946
.
5.
Banerjee, S., and Lahey, R. T., Jr., 1984, “Advances in Two-Phase Flow Instrumentation,” Advances in Nuclear Science and Technology, Lewins, J., and Becker, M., eds., Plenum Press, New York, Vol. 13, pp. 227–414.
6.
Barber
D. C.
, and
Brown
B. H.
,
1984
, “
Applied Potential Tomography
,”
Journal of Physics E: Scientific Instruments
, Vol.
17
, pp.
723
733
.
7.
Barber, D. C., and Brown, B. H., 1985, “Recent Developments in Applied Potential Tomography-APT,” Proceedings of the Ninth International Conference on Information Processing in Medical Imaging, Washington, D.C.
8.
Barnea
D.
,
Shoham
O.
,
Taitel
Y.
, and
Duckler
A. E.
,
1980
, “
Flow Pattern Transition for Gas-Liquid Flow in Horizontal and Inclined Pipes
,”
International Journal of Multiphase Flow
, Vol.
6
, pp.
217
225
.
9.
Bergles, A. E., 1969, “Electrical Probes for the Study of Two-Phase Flows,” Proceedings of the Eleventh National ASME/AIChE Heat Transfer Conference, Minneapolis, pp. 70–81.
10.
Bernier, R. J. N., 1981, “Unsteady Two-Phase Flow Instrumentation and Measurement,” Report No. E200.4, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA.
11.
Bolman, H., van Koppen, C. W. J., and Raas, L. J., 1974, “Some Investigation on the Influence of the Heat Flux on Flow Patterns in Vertical Boiler Tubes,” European Two-Phase Flow Group Meeting, Harwell, Paper A2.
12.
Brown
R. C.
,
Andreussi
P.
, and
Zanelli
S.
,
1978
, “
The Use of Wire Probes for the Measurement of Liquid Film Thickness in Annular Gas-Liquid Flows
,”
Canadian Journal of Chemical Engineering
, Vol.
56
, pp.
754
757
.
13.
Bruggeman
D. A. G.
,
1935
, “
Berechnung Verschiedener Physikalischer Konstanten von Heterogenen Substanze
,”
Annalen Physik
, Leipzig, Vol.
24
, p.
363
363
.
14.
Burgess
J. M.
, and
Calderbank
P. H.
,
1975
, “
The Measurement of Bubbles in Two-Phase Dispersions-III: Bubble Properties in a Freely Bubbling Fluidized-Bed
,”
Chemical Engineering Science
, Vol.
30
, pp.
1511
1518
.
15.
Calderbank, P. H., Pereira, J., and Burgess, J. M., 1976, “The Physical and Mass Transfer Properties of Bubbles in Fluidized Beds of Electrically Conducting Particles,” Fluidization Technology, Keairns, D. L., ed., Hemisphere Publishing, Washington, D. C., Vol. 1, pp. 115–167.
16.
Ceccio
S. L.
, and
Brennen
C. E.
,
1991
, “
Observations of the Dynamics and Acoustics of Traveling Bubble Cavitation
,”
Journal of Fluid Mechanics
, Vol.
233
, pp.
633
660
.
17.
Ceccio
S. L.
, and
Brennen
C. E.
,
1992
, “
Dynamics of Attached Cavities on Bodies of Revolution
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
114
, pp.
93
99
.
18.
Chang, J. S., Girard, R., Raman, R., and Tran, F. B. P., 1984, “Measurement of Void Fraction in Vertical Gas-Liquid Two-Phase Flow by Ring Type Capacitance Transducers,” Mass Flow Measurements-1984, Hedrick, T. R., and Reimer, R. M., eds., ASME, New Orleans, FED-Vol. 17, pp. 93–99.
19.
Cheremisinoff, N. P., 1977, “An Experimental and Theoretical Investigation of Horizontal Stratified and Annular Two-Phase Flow with Heat Transfer,” Ph.D. thesis, Clarkson College of Technology, Potsdam, NY.
20.
Cheremisinoff, N. P., 1986, Instrumentation for Complex Fluid Flows, Technomic Publishing Inc., Lancaster, PA, pp. 73–103.
21.
Clark
N. N.
,
Seiss
R.
, and
Turton
R.
,
1992
, “
Probe Measurements in Gas-Liquid Systems
,”
Flow Measurement and Instrumentation
,” Vol.
3
, pp.
17
23
.
22.
Coney
M. W. E.
,
1978
, “
The Theory and Application of Conductance Probes for the Measurement of Liquid Film Thickness in Annular Gas-Liquid Flows
,”
Canadian Journal of Chemistry
, Vol.
56
, pp.
754
757
.
23.
Cranfield
R. R.
,
1972
, “
A Probe for Bubble Detection and Measurement in Large Particle Fluidised Beds
,”
Chemical Engineering Science
, Vol.
27
, pp.
239
245
.
24.
Das
R. K.
, and
Pattanayak
S.
,
1993
, “
Electrical Impedance Method for Flow Regime Identification in Vertical Upward Gas-Liquid Two-Phase Flow
,”
Measurement Science and Technology
, Vol.
4
, pp.
1457
1463
.
25.
Delil, A. A. M., 1987, “Feasibility Demonstration of a Sensor for High-Quality Two-Phase Flow,” Report No. NLR TR 87009 U, National Aerospace Laboratory, Amsterdam, the Netherlands, pp. 8–13.
26.
Dickin
F. J.
,
Williams
R. A.
, and
Beck
M. S.
,
1993
, “
Determination of Composition and Motion of Multicomponent Mixtures in Process Vessels using Electrical Impedance Tomography-I. Principles and Process Engineering Applications
,”
Chemical Engineering Science
, Vol.
48
, pp.
1883
1897
.
27.
Fasching
G. E.
, and
Smith
N. S.
,
1991
, “
A Capacitive System for Three-Dimensional Imaging of Fluidized Beds
,”
Review of Scientific Instruments
, Vol.
62
, pp.
2243
2251
.
28.
Geraets
J. J. M.
, and
Borst
J. C.
,
1988
, “
A Capacitance Sensor for Two-Phase Void Fraction Measurement and Flow Pattern Identification
,”
International Journal of Multiphase Flow
, Vol.
14
, pp.
305
320
.
29.
Gunn
D. J.
, and
Al-Doori
H. H.
,
1985
, “
The Measurement of Bubble Flows in Fluidized Beds by Electrical Probes
,”
International Journal of Multiphase Flow
, Vol.
11
, pp.
535
551
.
30.
Hardy
J. E.
, and
Hylton
J. O.
,
1984
, “
Electrical Impedance String Probes for Two-Phase Void and Velocity Measurements
,”
International Journal of Multiphase Flow
, Vol.
10
, pp.
541
556
.
31.
Hewitt, G. F., 1978, Measurement of Two Phase Flow Parameters, Academic Press, London, pp. 57–60, 182.
32.
Hua, P., Webster, J. G., and Tompkins, W. J., 1987, “Effect of the Measurement Method on Noise Handling and Image Quality of EIT Imaging,” Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, IEEE, Boston, Vol. 3, pp. 1429–1430.
33.
Huang
S. M.
,
Xie
C. G.
,
Thorn
R.
,
Snowden
D.
, and
Beck
M. S.
,
1992
, “
Design of Sensor Electronics for Electrical Capacitance Tomography
,”
IEE Proceedings: Part G
, Vol.
139
, pp.
83
88
.
34.
Isaacson, D., and Cheney, M., 1990, “Current Problems in Impedance Imaging,” Inverse Problems in Partial Differential Equations, Coliton, D., Ewing, R., and Rundell, W., eds., SIAM, Philadelphia, pp. 141–149.
35.
Jones
O. C.
, and
Delhaye
J.
,
1976
, “
Transient and Statistical Measurement Techniques for Two-Phase Flows: A Critical Review
,”
International Journal of Multiphase Flow
, Vol.
3
, pp.
89
116
.
36.
Jones
O. C.
,
Lin
J. T.
, and
Ovacik
L.
,
1992
, “
Investigation of Electrical Impedance Imaging Relative to Two-Phase, Gas-Liquid Flows
,”
Chemical Engineering Communications
, Vol.
118
, pp.
299
325
.
37.
Jones
O. C.
,
Lin
J. T.
,
Ovacik
L.
, and
Shu
H.
,
1993
, “
Impedance Imaging Relative to Gas-Liquid Systems
,”
Nuclear Engineering and Design
, Vol.
141
, pp.
159
176
.
38.
Jones, O. C., Lin, J. T., Shu, H., Ovacik, L., and He, Y., 1994, “Impedance Imaging Relative to Binary Mixtures,” Fifth International Symposium on Liquid-Solid Flows, ASME, Lake Tahoe, NV.
39.
Jones, O. C., 1995, private communication.
40.
Kataoka
I.
,
Ishii
M.
, and
Serizawa
A.
,
1986
, “
Local Formulation and Measurements of Interfacial Area Concentration in Two-Phase Flow
,”
International Journal of Multiphase Flow
, Vol.
12
, pp.
505
529
.
41.
Kataoka
I.
, and
Serizawa
A.
,
1990
, “
Interfacial Area Concentration in Bubbly Flow
,”
Nuclear Engineering and Design
, Vol.
120
, pp.
163
180
.
42.
Kelessidis
V. C.
, and
Dukler
A. E.
,
1989
, “
Modeling Flow Pattern Transitions for Upward Gas-Liquid Flow in Vertical Concentric and Eccentric Annuli
,”
International Journal of Multiphase Flow
, Vol.
15
, pp.
173
191
.
43.
Keska, J. K., 1990, “Some Methodical and Experimental Aspects of Measurement of a Void Fraction in Gas-Liquid Flows,” Advances in Gas Liquid Flows, Kim, J. H., Rohatgi, U. S., and Hashemi, A., eds., ASME, Dallas, pp. 139–145.
44.
Khan
S. H.
, and
Abdullah
F.
,
1993
, “
Finite Element Modelling of Multielectrode Capacitive Systems for Flow Imaging
,”
IEE Proceedings: Part G
, Vol.
140
, pp.
216
222
.
45.
Kim
Y.
,
Webster
J. G.
, and
Tompkins
W. J.
,
1983
, “
Electrical Impedance Imaging of the Thorax
,”
Journal of Microwave Power
, Vol.
18
, pp.
245
257
.
46.
Kim, M., and Kang, H., 1990, “The Development of a Flush-Wire Probe and Calibration Technique for Measuring Liquid Film Thickness,” Advances in Gas Liquid Flows, Kim, J. H., Rohatgi, U. S., and Hashemi, A., eds., ASME, Dallas, pp. 131–138.
47.
Klug, F., and Mayinger, F., 1993, “Novel Impedance Measuring Technique for Flow Composition in Multi-phase Flows,” ANS Proceedings: 1993 National Heat Transfer Conference, American Nuclear Society, Atlanta, pp. 76–83.
48.
Koskie
J. E.
,
Mudawar
I.
, and
Tiederman
W. G.
,
1989
, “
Parallel-Wire Probes for the Measurement of Thick Liquid Films
,”
International Journal of Multiphase Flow
, Vol.
15
, pp.
521
530
.
49.
Kyto¨maa
H. K.
, and
Brennen
C. E.
,
1991
, “
Small Amplitude Kinematic Wave Propagation in Two-Component Media
,”
International Journal of Multiphase Flow
, Vol.
17
, pp.
13
26
.
50.
Kyto¨maa, H. K., 1987, “Stability of the Structure in Multicomponent Flows,” Report No. E200.24, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA.
51.
Lamarre
E.
, and
Melville
W. K.
,
1992
, “
Instrumentation for the Measurement of Void-Fraction in Breaking Waves: Laboratory and Field Results
,”
IEEE Journal of Oceanic Engineering
, Vol.
17
, pp.
204
215
.
52.
Lemonnier
H.
,
Nakach
R.
,
Favreau
C.
, and
Selmer-Olsen
S.
,
1991
, “
Sensitivity Analysis of an Impedance Void Meter to the Void Distribution in Annular Flow: a Theoretical Study
,”
Nuclear Engineering and Design
, Vol.
126
, pp.
105
112
.
53.
Lin, J.-T., Jones, O. C., Ovacik, L., and Shu, H.-J., 1993, “Advances in Impedance Imaging Relative to Two-Phase Flow,” ANS Proceedings: 1993 National Heat Transfer Conference, American Nuclear Society, Atlanta, pp. 68–75.
54.
Lin
P. Y.
, and
Hanratty
T. J.
,
1987
, “
Detection of Slug Flow From Pressure Measurements
,”
International Journal of Multiphase Flow
, Vol.
13
, pp.
13
21
.
55.
Maxwell, J., 1881, A Treatise on Electricity and Magnetism, Clarendon Press, Oxford, England.
56.
Merilo
M.
,
Dechene
R. L.
, and
Cichowlas
W. M.
,
1977
, “
Void Fraction Measurement with a Rotating Electric Field Conductance Gauge
,”
ASME Journal of Heat Transfer
, Vol.
99
, pp.
330
332
.
57.
Miya
M.
,
Woodmansee
D. E.
, and
Hanratty
T. J.
,
1971
, “
A Model for Roll Waves in Gas-Liquid Flow
,”
Chemical Engineering Science
, Vol.
26
, pp.
1915
1931
.
58.
Nasr-El-Din
H.
,
Shook
C. A.
, and
Colwell
J.
,
1987
, “
A Conductivity Probe for Measuring Local Concentrations in Slurry Systems
,”
International Journal of Multiphase Flow
, Vol.
13
, pp.
365
378
.
59.
Olsen, H. O., 1967, “Theoretical and Experimental Investigations of Impedance Void Meters,” Report No. 118, Institutt for Atomenergi, Kjeller Research Establishment, Kjeller, Norway.
60.
O¨zgu¨
M. R.
,
Chen
J. C.
, and
Eberhardt
N.
,
1973
, “
A Capacitance Method for Measurement of Film Thickness in Two-Phase Flow
,”
Review of Scientific Instruments
, Vol.
44
, pp.
1714
1716
.
61.
Plaskowski, A., Beck, M. S., Thorn, R., and Dyakowski, T., 1995, Imaging Industrial Flows: Applications of Electrical Process Tomography, Institute of Physics Publishing, Bristol, England, pp. 127–141.
62.
Revankar
S. T.
, and
Ishii
M.
,
1992
, “
Local Interfacial Area Measurement in Bubbly Flow
,”
International Journal of Heat and Mass Transfer
, Vol.
35
, pp.
913
925
.
63.
Revankar
S. T.
, and
Ishii
M.
,
1993
, “
Theory and Measurement of Local Interfacial Area Using a Four Sensor Probe in Two-Phase Flow
,”
International Journal of Heat and Mass Transfer
, Vol.
36
, pp.
2997
3007
.
64.
Rowe
P. N.
, and
Masson
H.
,
1980
, “
Fluidised Bed Bubbles Observed Simultaneously by Probe and X-rays
,”
Chemical Engineering Science
, Vol.
35
, pp.
1443
1447
.
65.
Rowe
P. N.
, and
Masson
H.
,
1981
, “
Interaction of Bubble with Probes in Gas Fluidised Beds
,”
Transactions of the Institution of Chemical Engineers
, Vol.
59
, pp.
177
185
.
66.
Ruder
Z.
,
Hanratty
P. J.
, and
Hanratty
T. J.
,
1989
, “
Necessary Condition for the Existence of Stable Slugs
,”
International Journal of Multiphase Flow
, Vol.
15
, pp.
209
226
.
67.
Saiz-Jabardo
J. M.
, and
Boure
J. A.
,
1989
, “
Experiments on Void Fraction Waves
,”
International Journal of Multiphase Flow
, Vol.
15
, pp.
483
493
.
68.
Seagar
A. D.
,
Barber
D. C.
, and
Brown
B. H.
,
1987
, “
Electrical Impedance Imaging
,”
IEE Proceedings: Part A
, Vol.
134
, pp.
201
210
.
69.
Snell, C. C., Dechene, R. L., and Newton, R. E., 1978, “Two-Phase Relative Volume Fraction Measurement with a Rotating Field Conductance Gauge,” Measurements in Polyphase Flows, Stock, D. E., ed., ASME, San Francisco, pp. 21–24.
70.
Teyssedou
A.
, and
Tapucu
A.
,
1988
, “
Impedance Probe to Measure Local Void Fraction Profiles
,”
Review of Scientific Instruments
, Vol.
59
, pp.
631
638
.
71.
Tournaire
A.
,
1986
, “
Dependence of the Instantaneous Response of Impedance Probes on the Local Disturbance of the Void Fraction in a Pipe
,”
International Journal of Multiphase Flow
, Vol.
12
, pp.
1019
1024
.
72.
van der Welle
R.
,
1985
, “
Void Fraction, Bubble Velocity and Bubble Size in Two-Phase Flow
,”
International Journal of Multiphase Flow
, Vol.
11
, pp.
317
345
.
73.
Wang
Y. W.
,
Pei
B. S.
, and
Lin
W. K.
,
1991
, “
Verification of Using a Single Void Fraction Sensor to Identify Two-Phase Flow Patterns
,”
Nuclear Technology
, Vol.
95
, pp.
87
94
.
74.
Warrier, G. R., and Nguyen, T., 1993, “Void Fraction Investigation in Horizontal Gas-Liquid Two-Phase Flow,” Cavitation and Multiphase Flow Forum-1993, Furuya, O., ed., ASME, Washington, D.C., FED-Vol. 153, pp. 53–62.
75.
Webster, J. G., ed., 1990, Electrical Impedance Tomography, Adam Hilger, Bristol, England, pp. 1–20, 75–86, 175–200.
76.
Werther
J.
, and
Molerus
O.
,
1973
, “
The Local Structure of Gas Fluidized Beds-I. A Statistically Based Measuring System
,”
International Journal of Multiphase Flow
, Vol.
1
, pp.
103
122
.
77.
Wexler
A.
,
Fry
B.
, and
Neuman
M. R.
,
1985
, “
Impedance-Computed Tomography Algorithm and System
,”
Applied Optics
, Vol.
24
, pp.
3985
3992
.
78.
Xie
C. G.
,
Plaskowski
A.
, and
Beck
M. S.
,
1989
, “
8-Electrode Capacitance System for Two-Component Flow Identification-Part I: Tomographic Flow Imaging
,”
IEE Proceedings: Part A
, Vol.
136
, pp.
173
183
.
79.
Xie
C. G.
,
Plaskowski
A.
, and
Beck
M. S.
,
1989
, “
8-Electrode Capacitance System for Two-Component Flow Identification-Part 2: Flow Regime Identification
,”
IEE Proceedings: Part A
, Vol.
136
, pp.
184
190
.
80.
Xie
C. G.
,
Stott
A. L.
,
Plaskowski
A.
, and
Beck
M. S.
,
1990
, “
Design of Capacitance Electrodes for Concentration Measurement of Two-Phase Flow
,”
Measurement Science and Technology
, Vol.
1
, pp.
65
78
.
81.
Yorkey
T. J.
,
Webster
J. G.
, and
Tompkins
W. J.
,
1987
, “
Comparing Reconstruction Methods for Electrical Impedance Tomography
,”
IEEE Transactions on Biomedical Engineering
, Vol.
11
, pp.
843
852
.
82.
Yoshida
K.
,
Sakane
J.
, and
Shimizu
F.
,
1982
, “
A New Probe for Measuring Fluidized Bed Characteristics at High Temperatures
,”
Industrial Engineering Chemistry Fundamentals
, Vol.
21
, pp.
83
85
.
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