The present study aims at investigating the deformation mechanism of liquid-liquid interfaces by both the experimental and numerical approaches. The experiments reveal that the topology of an initial flat interface composed of Newtonian aqueous and Newtonian oil phases can be modulated as climbing or descending along a rotating rod according to the ratio of the kinematic viscosity between these two liquid phases. The measurements of the fluid flow fields by particle image velocimetry highlight the relationship between the appearance of the Taylor-Couette instability in the less viscous phase and the interface’s orientation. The increasing rod rotation speed expands the Taylor-Couette vortices and then intensifies the magnitude of the interface deformation. The numerical simulation by the volume of fluid method is in qualitative agreement with the experimental results, in particular the interface shape and the qualitative influence of different parameters, even under very high rotation speeds of the rod.

1.
G. G.
Fuller
and
J.
Vermant
, “
Editorial: Dynamics and rheology of complex fluid–fluid interfaces
,”
Soft Matter
7
,
7583
7585
(
2011
).
2.
R. J.
Stokes
and
D.
Fennell Evans
,
Fundamentals of Interfacial Engineering
(
Wiley-VCH
,
New York
,
1997
).
3.
Z.
Mohamed-Kassim
and
E. K.
Longmir
, “
Drop impact on a liquid/liquid interface
,”
Phys. Fluids
15
,
3263
3273
(
2003
).
4.
X. P.
Chen
,
S.
Mandre
, and
J. J.
Feng
, “
Partial coalescence between a drop and a liquid-liquid interface
,”
Phys. Fluids
18
,
051705
(
2006
).
5.
S.
Hartland
, “
The approach of a rigid sphere to a deformable liquid/liquid interface
,”
J. Colloid Interface Sci.
26
,
383
394
(
1968
).
6.
N.
Dietrich
,
S.
Poncin
, and
H. Z.
Li
, “
Passage of a settling sphere through a liquid-liquid interface
,”
Exp. Fluids
50
,
1293
1303
(
2011
).
7.
A. F.
Jones
and
S. D. R.
Wilson
, “
The film drainage problem in droplet coalescence
,”
J. Fluid Mech.
87
,
263
288
(
1978
).
8.
Z.
Mohamed-Kassim
and
E. K.
Longmire
, “
Drop coalescence through a liquid/liquid interface
,”
Phys. Fluids
16
,
2170
2181
(
2004
).
9.
R.
Bonhomme
,
J.
Magnaudet
,
F.
Duval
, and
B.
Piar
, “
Inertial dynamics of air bubbles crossing a horizontal fluid-fluid interface
,”
J. Fluid Mech.
707
,
405
443
(
2012
).
10.
N.
Dietrich
,
S.
Poncin
,
S.
Pheulpin
, and
H. Z.
Li
, “
Bubble passage at a liquid-liquid interface
,”
AIChE J.
54
,
594
600
(
2008
).
11.
A. S.
Geller
,
S. H.
Lee
, and
L. G.
Leal
, “
The creeping motion of a spherical particle normal to a deformable interface
,”
J. Fluid Mech.
169
,
27
69
(
1986
).
12.
D.
Bonn
,
M.
Kobylko
,
S.
Bohn
,
J.
Meunier
,
A.
Morozov
, and
W.
van Saarloos
, “
Rod-climbing effect in Newtonian fluids
,”
Phys. Rev. Lett.
93
,
214503
(
2004
).
13.
K.
Weissenberg
, “
A continuum theory of rheological phenomena
,”
Nature
159
,
310
311
(
1947
).
14.
G. I.
Taylor
, “
Stability of a viscous liquid contained between two rotating cylinders
,”
Philos. Trans. R. Soc., A
223
,
289
343
(
1923
).
15.
R. J.
Stokes
and
D. F.
Evans
,
Fundamentals of Interfacial Engineering
(
Wiley-VCH
,
New York
,
1997
).
16.
C. W.
Hirt
and
B. D.
Nichols
, “
Volume of fluid for the dynamics of free boundaries
,”
J. Comput. Phys.
39
,
201
255
(
1981
).
17.
J. U.
Brackbill
,
D. B.
Kothe
, and
C.
Zemach
, “
A continuum method for modeling surface tension
,”
J. Comput. Phys.
100
,
335
354
(
1992
).
18.
D. L.
Youngs
, in
Numerical Methods for Fluid Dynamics
, edited by
K. W.
Morton
and
M. J.
Baines
(
Academic Press
,
New York
,
1982
).
19.
X.
Frank
and
H. Z.
Li
, “
Negative wake behind a sphere rising in viscoelastic fluids: A lattice Boltzmann investigation
,”
Phys. Rev. E
74
,
056307
(
2006
).
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