This study is concerned with the collision behavior of water droplets impacting onto a solid. Three-dimensional computer simulations are performed to understand the physics of phenomena. The Navier-Stokes equations for unsteady, incompressible, viscous fluid in a three-dimensional Cartesian coordinate system are approximated and solved by a finite difference method. The VOF (Volume-of-Fluid) technique is used to track free liquid surface. The effects of liquid viscosity, surface tension, gravity, and wettability between liquid and solid are taken into account. Normal and oblique collisions of droplets with the substrate are simulated at relatively low impact inertia of droplets. Experiments are also carried out in order to validate the numerical results. The numerical results agree reasonably well with experiments. The physics of phenomena is discussed in detail from theoretical aspects.

Volume Subject Area:
Fluids Engineering
Topics:
Collisions (Physics), Drops, Water, Fluids, Physics, Computer simulation, Finite difference methods, Gravity (Force), Inertia (Mechanics), Navier-Stokes equations, Surface tension, Viscosity
1.
Fujimoto
H.
and
Hatta
N.
 “
Deformation and Rebounding Processes of a Water Droplet Impinging on a Flat Surface Above Leidenfrost Temperature
,”
Transactions of the ASME Journal of Fluids Engineering
,
118–2
(
1996
), pp.
142
–
149
.
2.
Fujimoto
H.
,
Ogino
T.
,
Takuda
H.
, and
Hatta
N.
 “
Collision of a Droplet with a Hemispherical Static Droplet on a Solid
,”
International Journal of Multiphase flow
, Vol.
27–7
(
2001
), pp.
1227
–
1245
.
3.
Fujimoto
H.
,
Takezaki
I.
,
Shiotani
Y.
,
Tong
A. Y.
, and
Takuda
H.
 “
Collision dynamics of two droplets impinging successively onto a hot solid
,”
ISIJ International
,
44–6
(
2004
), pp.
1049
–
1056
.
4.
A.Y. Tong, S. Kasliwal, H. Fujimoto and H. Takuda “Numerical Study on the Successive Impingement of Droplets onto a Substrate,” Proceedings of IMECE’04, ASME International Mechanical Congress and Exposition, Anaheim, CA. (November 2004).
5.
Bussmann
M.
,
Mostaghimi
J.
,
Chandra
S.
, “
On a three-dimensional volume tracking model of drop impact
,”
Physics of Fluids
, Vol.
11
, No.
6
, (
1999
), pp.
1406
–
1417
.
6.
Kothe
D. B.
,
Mjolsness
R. C.
 “
Ripple: A new model for incompressible with free surfaces
,”
AIAA Journal
,
30
(
11
) (
1992
), pp.
2694
–
2700
.
7.
Brackbill
J. U.
,
Kothe
D. B.
and
Zemach
C.
 “
A Continuum Method for Modeling Surface Tension
,”
Journal of Computational Physics
,
100
(
1992
), pp.
335
–
354
.
8.
Bussmann
M.
,
Chandra
S.
,
Mostaghimi
J.
, “
Modeling the splash of a droplet impacting a solid surface
,”
Physics of Fluids
, Vol.
12
, No.
12
, (
2000
), pp.
3121
–
3132
.
9.
Pasandideh-Fard
M.
,
Chandra
S.
,
Mostaghimi
J.
, “
A three-dimensional model of droplet impact and solidification
,”
International Journal of Heat and Mass Transfer
45
(
2002
), pp.
2229
–
2242
10.
Ghafouri-Azar
R.
,
Shakeri
S.
,
Chandra
S.
,
Mostaghimi
J.
, “
Interactions between molten metal droplets impinging on a solid surface
,”
International Journal of Heat and Mass Transfer
46
(
2003
), pp.
1395
–
1407
11.
Baer
T. A.
,
Cairncross
R. A.
,
Schunk
P. R.
,
Rao
R. R.
,
Sackinger
P. A.
, “
A finite element method for free surface flows of incompressible fluids in three dimensions. Part II, Dynamic wetting lines
,”
International Journal for Numerical Method in Fluids
,
33
(
2000
), pp.
405
–
427
.
12.
Theodorakakos
A.
,
Bergeles
G.
, “
Simulation of sharp gasliquid interface using VOF method and adaptive grid local refinement around the interface
,”
International Journal of Numerical Methods in Fluids
45
(
2004
),
421
–
439
.
13.
Hirt
C. W.
and
Nichols
B. D.
, “
Volume of fluid (VOF) method for the dynamics of free boundaries
,”
Journal of Computational Physics
,
39
(
1981
), pp.
201
–
225
.
14.
Yabe
T.
,
Xiao
F.
and
Utsumi
T.
:
Journal of Computational Physics
,
169
(
2001
), pp.
556
–
593
.
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