The details on dynamics and breakup processes of liquid sheets are numerically investigated by considering two liquid sheet arrangements: the contraction of liquid sheet in a still quiescent gas medium, and a moving liquid sheet in a gas medium of much higher velocity compared with the liquid sheet. The first part of the study reveals that the surface tension forms the capillary wave on the liquid sheet surface. By extensive calculation, it is conformed that only surface tension force cannot disintegrate the liquid sheet. The dragging of liquid by co-flowing gas is very important for the occurrence of sheet breakup. To prove this concept, the second part of the investigation is performed, which reveals the details of breakup processes. Two effects are observed: the aerodynamic effect and the surface tension effect. The main function of the aerodynamic effect is to stretch the liquid sheet by drag force and create the steps on the sheet surface which is then followed by a pair of vortices and stagnation point prior to the end of every step. When the thickness of the sheet becomes thin enough, the dragging of liquid by the gas flow at the upstream of the neck part of the bulbous tip causes formation of a pair of vortices and stagnation point on the thin portion of the liquid sheet restricts the liquid flow and eventually the breakup occurs.

References

References
1.
Lefebvre
,
A. H.
, 1989,
Atomization and Sprays
,
Hemisphere Publishing
,
Washington, D.C
.
2.
Brown
,
D. R.
, 1961, “
A Study of the Behaviour of a Thin Sheet of Moving Liquid
,”
J. Fluid Mech.
,
10
, pp.
297
305
.
3.
Savart
,
F.
, 1833, “
Suite du Memoire sur le Choc d’une Veine Liquide Lancee Contre un Plan Circulaire
,”
Ann. Chim. Phys.
,
54
, pp.
113
165
.
4.
Taylor
,
G.
, 1959, “
The Dynamics of Thin Sheets of Fluid. II. Waves on Fluid Sheets
,”
Proc. Royal Soc. London A
,
253
, pp.
296
312
.
5.
Taylor
,
G.
, 1959, “
The Dynamics of Thin Sheets of Fluid. III. Disintegration of Fluid Sheets
,”
Proc. Royal Soc. London A
,
253
, pp.
313
321
.
6.
Taylor
,
G.
, 1960, “
Formation of Thin Flat Sheets of Water
,”
Proc. Royal Soc. London A
,
259
, pp.
1
17
.
7.
Lin
,
S. P.
, and
Roberts
,
G.
, 1981, “
Waves in a Viscous Liquid Curtain
,”
J. Fluid Mech.
,
112
, pp.
443
458
.
8.
Mehring
,
C.
,
Kim
,
I.
, and
Sirignano
,
W. A.
, 1997, “
Symmetric Distortion of a Thin Liquid Sheet With Infinite Length
,” Proceedings of the 10th Annual Conference On Liquid Atomzation Spray Systems,
ILASS
,
North and South America
, pp.
117
121
.
9.
Mehring
,
C.
, and
Sirignano
,
W. A.
, 1998, “
Nonlinear Capillary Wave Distortion and Disintegration of Thin Planar Liquid Sheets
,” Proceedings of the 11th Annual Conference On Liquid Atomzation Spray Systems,
ILASS
,
North and South America
, ILASS, North and South America, pp.
155
159
.
10.
Lin
,
S. P.
, 1981, “
Stability of a Viscous Liquid Curtain
,”
J. Fluid Mech.
,
104
, pp.
111
118
.
11.
York
,
J. L.
,
Stubbs
,
H. E.
, and
Tek
,
M. R.
, 1953, “
The Mechanism of Disintegration of Liquid Sheets
,”
Trans. ASME
,
75
, pp.
1279
1286
.
12.
Squire
,
H. B.
, 1953, “
Investigation of the Instability of a Moving Liquid Film
,”
Br. J. Appl. Phys.
,
4
, pp.
167
169
.
13.
Hagerty
,
W. W.
, and
Shea
,
J. F.
, 1955, “
A Study of the Stability of Plane Fluid Sheets
,”
J. Appl. Mech.
,
22
, pp.
509
514
.
14.
Clark
,
C. J.
, and
Dombrowski
,
N.
, 1972, “
Aerodynamic Instability and Disintegration of Inviscid Liquid Sheets
,”
Proc. Royal Soc. London A
,
329
, pp.
467
478
.
15.
Mansour
,
A.
, and
Chigier
,
N.
, 1989, “
Disintegration of Liquid Sheets
,”
Phys. Fluids A
,
2
(
5
), pp.
706
719
.
16.
Mansour
,
A.
, and
Chigier
,
N.
, 1991, “
Dynamic Behavior of Liquid Sheets
,”
Phys. Fluids A
,
3
(
12
), pp.
2971
2980
.
17.
Mehring
,
C.
, and
Sirignano
,
W. A.
, 1999, “
Nonlinear Distortion of Infinitely Long Thin Planar and Annular Liquid Sheets
,”
J. Fluid Mech.
,
388
, pp.
69
113
.
18.
Gueyffier
,
D.
,
Li
,
J.
,
Nadim
,
A.
,
Scardovelli
,
R.
, and
Zaleski
,
S.
, 1999, “
Volume-of-Fluid Interface Tracking With Smoothed Surface Stress Methods for Three-Dimensional Flows
,”
J. Comput. Phys.
,
152
, pp.
423
456
.
19.
Brackbill
,
J. U.
,
Kothe
,
D. B.
, and
Zemach
,
C.
, 1991, “
A Continuum Method for Modeling Surface Tension
,”
J. Comput. Phys.
,
100
, pp.
335
354
.
20.
Hirt
,
C. W.
, and
Nichols
,
B. D.
, 1981, “
Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries
,”
J. Comput. Phys.
,
39
, pp.
201
225
.
21.
Welch
,
S. W. J.
, and
Wilson
,
J.
, 2000, “
A Volume of Fluid Based Method for Fluid Flows With Phase Change
,”
J. Comput. Phys.
,
160
, pp.
662
682
.
22.
Goedde
,
E. F.
, and
Yuen
,
M. C.
, 1970, “
Experiments on Liquid Jet Instability
,”
J. Fluid Mech.
,
40
(
3
), pp.
495
511
.
23.
Umemura
,
A.
, and
Wakashima
,
Y.
, 2002, “
Atomization Regimes of a Round Liquid Jet With Near-Critical Mixing Surface at High Pressure
,”
Proc. Combust. Inst.
,
29
, pp.
633
640
.
24.
Umemura
,
A.
, 2004, “
Micro-Gravity Study on Instability of Near Critical Mixing Surface Jet (Mechanisms of Rayleigh-Taylor Instability Excitation at Nozzle Exit and Short Spacing Disintegration)
,”
J. Combust. Soc. Jpn.
,
46
(
135
), pp.
50
59
(in Japanese).
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