Thermoconvective instabilities in a bilayer liquid–gas system with a deformed interface are investigated. In the first part of the work which is devoted to a linear approach, emphasis is put on the role of the upper gas layer on the instability phenomenon. The condition to be satisfied by the gas to remain purely conductive is established. The so-called Oberbeck–Boussinesq approximation is discussed and its range of validity is carefully defined. Instead of the classical Rayleigh, Marangoni, crispation, and Galileo numbers, new dimensionless groups are introduced. A critical comparison with several previous works is made. The nonlinear analysis consists in studying the different convective patterns which can appear above the threshold. Particular attention is devoted to the shape of the interface and the so-called “hybrid” relief. The amplitude of the deformation is also determined and comparison with experimental data is discussed.

1.
E. L. Koschmieder, Bénard Cells and Taylor Vortices (Cambridge University Press, Cambridge, 1993).
2.
S.
Rasenat
,
F. H.
Busse
, and
I.
Rehberg
, “
A theoretical and experimental study of double-layer convection
,”
J. Fluid Mech.
199
,
519
(
1989
).
3.
D. Johnson, R. Narayanan, and P. C. Dauby, “The effect of air height on the pattern formation in liquid–air bilayer convection,” in Fluids Dynamics at Interfaces, edited by W. Shyy and R. Narayanan (Cambridge University Press, Cambridge, 1999).
4.
L. E.
Scriven
and
C. V.
Sterling
, “
On cellular convection driven by surface-tension gradients: Effects of mean surface tension and surface viscosity
,”
J. Fluid Mech.
19
,
321
(
1964
).
5.
A.
Smith
, “
On convective instability induced by surface-tension gradients
,”
J. Fluid Mech.
24
,
401
(
1966
).
6.
R. W.
Zeren
and
W. C.
Reynolds
, “
Thermal instabilities in two-fluid horizontal layers
,”
J. Fluid Mech.
53
,
305
(
1972
).
7.
M.
Takashima
, “
Surface tension driven instability in a horizontal liquid layer with a deformable free surface. I. Stationary convection
,”
J. Phys. Soc. Jpn.
50
,
2745
(
1981
).
8.
M.
Takashima
, “
Surface tension driven instability in a horizontal liquid layer with a deformable free surface. II. Overstability
,”
J. Phys. Soc. Jpn.
50
,
2751
(
1981
).
9.
J.
Reichenbach
and
H.
Linde
, “
Linear perturbation analysis of surface-tension-driven convection at a plane interface
,”
J. Colloid Interface Sci.
84
,
433
(
1981
).
10.
E. N.
Ferm
and
D. J.
Wolkind
, “
Onset of R-B-M instability: Comparison between theory and experiment
,”
J. Non-Equilib. Thermodyn.
7
,
169
(
1982
).
11.
D. A.
Goussis
and
R. E.
Kelly
, “
On the thermocapillary instabilities in a liquid layer heated from below
,”
Int. J. Heat Mass Transf.
33
,
2237
(
1990
).
12.
G.
Gouesbet
,
J.
Maquet
,
C.
Rozé
, and
R.
Darrigo
, “
Surface-tension and coupled buoyancy-driven instability in a horizontal liquid layer. Overstability and exchange of stability
,”
Phys. Fluids A
2
,
903
(
1990
).
13.
C.
Pérez Garcia
and
G.
Carneiro
, “
Linear stability analysis of B-M convection in fluids with a deformable free surface
,”
Phys. Fluids A
3
,
292
(
1991
).
14.
Y.
Renardy
and
M.
Renardy
, “
Bifurcating solutions at the onset of convection in the B problem for two fluids
,”
Physica D
32
,
227
(
1988
).
15.
V. C.
Regnier
,
P. M.
Parmentier
,
P. C.
Dauby
, and
G.
Lebon
, “
Square cells in gravitational and capillary thermoconvection
,”
Phys. Rev. E
55
,
6860
(
1997
).
16.
K.
Eckert
,
M.
Bestehorn
, and
A.
Thess
, “
Square cells in surface-tension-driven Bénard convection: Experiment and theory
,”
J. Fluid Mech.
356
,
155
(
1998
).
17.
P.
Cerisier
,
C.
Jamond
,
J.
Pantaloni
, and
J. C.
Charmet
, “
Déformation de la surface libre en convection de Bénard–Marangoni
,”
J. Phys.
45
,
405
(
1984
).
18.
I. B. Simanovskii and A. A. Nepomnyashchy, Convective Instabilities in Systems with Interface (Gordon and Breach, Amsterdam, 1993).
19.
D. D. Joseph, Stability of Fluid Motion I/II (Springer, Berlin, 1976).
20.
R.
Sélak
and
G.
Lebon
, “
Bénard–Marangoni thermoconvective instability in presence of a temperature-dependent viscosity
,”
J. Phys.
3
,
1185
(
1993
).
21.
R.
Sélak
and
G.
Lebon
, “
Rayleigh–Marangoni thermoconvective instability with non-Boussinesq corrections
,”
Int. J. Heat Mass Transf.
40
,
785
(
1996
).
22.
P. G. Drazin and W. H. Reid, Hydrodynamic Stability (Cambridge University Press, Cambridge, 1981).
23.
V. C. Regnier, “Instabilités thermoconvectives dans les fluides à interfaces déformables,” Ph.D. thesis, Université de Liège, 1998.
24.
E. L.
Koschmieder
, “
On convection under an air surface
,”
J. Fluid Mech.
30
,
9
(
1967
).
25.
H.
Jeffreys
, “
Some cases of instability in fluid motion
,”
Proc. R. Soc. London, Ser. A
118
,
195
(
1928
).
26.
D. A.
Nield
, “
Surface tension and buoyancy effects in cellular convection
,”
J. Fluid Mech.
9
,
341
(
1964
).
27.
S. J.
Vanhook
,
M. F.
Schatz
,
J. B.
Swift
,
W. D.
McCormick
, and
H. L.
Swinney
, “
Long-wavelength surface-tension-driven Bénard convection: Experiment and theory
,”
J. Fluid Mech.
345
,
45
(
1997
).
28.
V. C.
Regnier
and
G.
Lebon
, “
Time-growth and correlation length of fluctuations in thermocapillary convection with surface deformation
,”
Q. J. Mech. Appl. Math.
48
,
57
(
1995
).
29.
C.
Normand
,
Y.
Pomeau
, and
M.
Velarde
, “
Convective instability: A physicist’s approach
,”
Rev. Mod. Phys.
49
,
581
(
1977
).
30.
C.
Pérez-Garcı́a
,
B.
Echebarrı́a
, and
M.
Bestehorn
, “
Thermal properties in surface-tension-driven convection
,”
Phys. Rev. E
57
,
475
(
1998
).
31.
E. L.
Koschmieder
and
S. A.
Prahl
, “
Surface-tension-driven Bénard convection in small containers
,”
J. Fluid Mech.
215
,
571
(
1990
).
32.
J.
Pearson
, “
On convection cells induced by surface tension
,”
J. Fluid Mech.
4
,
489
(
1958
).
33.
L.
Segel
, “
The nonlinear interaction of a finite number of disturbances to a layer of fluid heated from below
,”
J. Fluid Mech.
21
,
359
(
1965
).
34.
A.
Cloot
and
G.
Lebon
, “
A nonlinear stability analysis of the Bénard–Marangoni problem
,”
J. Fluid Mech.
145
,
447
(
1984
).
35.
P.
Parmentier
,
V. C.
Regnier
,
G.
Lebon
, and
J. C.
Legros
, “
A nonlinear analysis of coupled gravitational and capillary thermoconvection in thin fluid layers
,”
Phys. Rev. E
54
,
411
(
1996
).
36.
P. C.
Dauby
and
G.
Lebon
, “
Bénard–Marangoni instability in rigid rectangular containers
,”
J. Fluid Mech.
329
,
25
(
1996
).
37.
S. H.
Davis
and
G. M.
Homsy
, “
Energy stability theory for free-surface problems: Buoyancy-thermocapillary layers
,”
J. Fluid Mech.
98
,
527
(
1980
).
38.
M.
Cross
and
P.
Hohenberg
, “
Pattern formation outside of equilibrium
,”
Rev. Mod. Phys.
5
,
851
(
1993
).
39.
J.
Kraska
and
R.
Sani
, “
Finite amplitude Bénard–Rayleigh convection
,”
Int. J. Heat Mass Transf.
22
,
535
(
1979
).
40.
S.
Rosenblat
,
S. H.
Davis
, and
G. M.
Homsy
, “
Nonlinear Marangoni convection in bounded layers. 1. Circular cylindrical containers
,”
J. Fluid Mech.
120
,
91
(
1982
).
41.
S. H.
Davis
, “
Thermocapillary instabilities
,”
Annu. Rev. Fluid Mech.
19
,
403
(
1987
).
42.
A.
Golovin
,
A.
Nepomnyashchy
, and
L.
Pismen
, “
Pattern formation in large-scale Marangoni convection with deformable surface
,”
Physica D
81
,
117
(
1995
).
43.
L.
Hadji
, “
Nonlinear analysis of the coupling between interface deflection and hexagonal patterns in Rayleigh–Bénard–Marangoni convection
,”
Phys. Rev. E
53
,
5982
(
1996
).
44.
S. H. Davis, Rupture of Thin Liquids Films, Waves on Fluid Interfaces (Academic, New York, 1983).
45.
T.
Funada
and
M.
Kotani
, “
A numerical diffusion equation governing surface deformation in the Marangoni convection
,”
J. Phys. Soc. Jpn.
55
,
3857
(
1986
).
46.
T.
Funada
, “
Nonlinear surface waves driven by the Marangoni instability in a heat transfer system
,”
J. Phys. Soc. Jpn.
56
,
2031
(
1987
).
47.
A.
Golovin
,
A.
Nepomnyashchy
, and
L.
Pismen
, “
Interaction between short-scale Marangoni convection and long-scale deformational instability
,”
Phys. Fluids
6
,
34
(
1994
).
This content is only available via PDF.
You do not currently have access to this content.