A new technique of measuring void fraction in magnetic fluid using electromagnetic induction was proposed. In order to establish the measuring method, a feasibility study was conducted experimentally with an aid of numerical analysis. From the results of static experiment and numerical analysis, it was obtained that there exists a linear relationship between the void fraction and the measured electromotive force, when induction coils were connected in series for Helmholtz excitation coils, regardless of distribution of air bubbles in magnetic fluid. By applying the calibrated linear relationship to actual two-phase situations, it was revealed that the proposed method yielded quite reasonable account for measuring the void fraction, showing excellent agreement with the mechanical measured data in the two-phase flow apparatus, and with the published correlation of the drift flux model. From the results of the present investigation, it was proved that the proposed technique is feasible for the actual measurement of void fraction in two-phase flow of magnetic fluid.

1.
Ishimoto
,
J.
,
Okubo
,
M.
,
Nisihiyama
,
N.
, and
Kamiyama
,
S.
,
1993
, “
Basic Study on an Energy Conversion System Using Gas-liquid Two-Phase Flows of Magnetic Fluid
,”
Jpn. Soc. Mech. Eng., Ser. B
,
59
(
566
), pp.
3071
3077
(in Japanese).
2.
Hulzler
,
S.
,
Weaire
,
D.
,
Elias
,
F.
, and
Janiaud
,
E.
,
2002
, “
Juggling with Bubbles in Cylindrical Ferrofluid Foams
,”
Philos. Mag. Lett.
,
82
(
5
), pp.
297
301
.
3.
Hewitt, G. F., and Hall-Talor, N. S., 1970, Annular Two-Phase Flow, Pergamon Press, Oxford, pp. 259–265.
4.
Cummings
,
P. D.
, and
Chanson
,
H.
,
1997
, “
Air Entrainment in the Developing Flow Region of Plunging
,”
ASME J. Fluids Eng.
,
119
, pp.
603
608
.
5.
Herringe
,
R. A.
, and
Davis
,
M. R.
,
1976
, “
Structural Development of Gas-Liquid Mixture Flows
,”
J. Fluid Mech.
,
73
, pp.
97
123
.
6.
Ishimoto
,
J.
,
Okubo
,
M.
, and
Kamiyama
,
S.
,
1995
, “
Basic Study on an Energy Conversion System Using Boiling Two-Phase Flows of Temperature-Sensitive Magnetic Fluid
,”
Jpn. Soc. Mech. Eng., Ser. B
,
61
(
581
), pp.
157
165
(in Japanese).
7.
Yamada, N., 1996, Electromagnetic Engineering, Tokyo, The Institute of Electrical Engineers of Japan, Tokyo p. 215 (in Japanese).
8.
Volkova, O., and Bossis, G., 2000, “Magnetorheolgy of Magnetic Holes Compared to Magnetic Particles,” 44(91), pp. 91–104.
9.
Hale
,
D. K.
,
1976
, “
The Physical Properties of Composite Materials
,”
J. Mater. Sci.
,
11
, pp.
2105
2141
.
10.
Bashtovoy, V. G., Berkovsky, B. M., and Vislovich, A. N., 1988, Introduction to Thermomechanics of Magnetic Fluids, Hemisphere Press, Washington, DC, pp. 121–124.
11.
Salomon, L., 1999, Two-Phase Flow in Complex Systems, John Wiley and Sons, New York, pp. 118–124.
12.
Graham, B., One-Dimensional Two-Phase Flow, McGraw-Hill, New York, pp. 89–103.
13.
Zuber
,
N.
, and
Findlay
,
J. A.
,
1965
, “
Average Volumetric Concentration in Two-Phase Flow System
,”
ASME J. Heat Transfer
,
87
, pp.
453
463
.
14.
Ishii
,
M.
,
1977
, “
One-Dimensional Drift-Flux Model and Constitutive Equations for Relative Motion Between Phases in Various Two-Phase Flow Regimes
,”
ANL Rep.
,
77
, p.
40
40
.