An orderly droplet splashing is established when a water droplet train impinges onto a superheated copper surface. The droplets continuously impinge onto the surface with a rate of 40,000 Hz, a diameter of 96 μm or 120 μm, and a velocity of 8.4 m/s or 14.5 m/s. The heat transfers under different wall temperatures are measured, and the corresponding droplet splashing is recorded and analyzed. The effects of wall temperature, droplet Weber number, and surface roughness on the transition of the droplet splashing are investigated. The results suggest that the transferred energy is kept a constant in the transition regime, but a sudden drop of around 25% is observed when it steps into post-transition regime, indicating that the Leidenfrost point is reached. A higher Weber number of droplet train results in a more stable splashing angle and a wider range of splashed droplet diameter. The surface roughness plays no significant role in influencing the splashing angle in the high Weber number case, but the rougher surface elevates the fluctuation of the splashing angle in the low Weber number case. On the rougher surface, the temporary accumulation of the impact droplets is observed, a “huge” secondary droplet can be formed and released. The continuous generation of the huge droplets is observed at a higher wall temperature. Based on the result of droplet tracking of the splashed secondary droplets, the diameter and velocity are correlated.

References

References
1.
Yarin
,
A.
,
2006
, “
Drop Impact Dynamics: Splashing, Spreading, Receding, Bouncing?
Ann. Rev. Fluid Mech.
,
38
(
1
), pp.
159
192
.
2.
Rioboo
,
R.
,
Tropea
,
C.
, and
Marengo
,
M.
,
2001
, “
Outcomes From a Drop Impact on Solid Surfaces
,”
Atomization Sprays
,
11
(
2
), pp.
155
166
.
3.
Bird
,
J. C.
,
Tsai
,
S. S.
, and
Stone
,
H. A.
,
2009
, “
Inclined to Splash: Triggering and Inhibiting a Splash With Tangential Velocity
,”
New J. Phys.
,
11
(
6
), p.
063017
.
4.
Wal
,
R. V.
,
Berger
,
G.
, and
Mozes
,
S.
,
2006
, “
The Splash/Non-Splash Boundary Upon a Dry Surface and Thin Fluid Film
,”
Exp. Fluids
,
40
(
1
), pp.
53
59
.
5.
Rioboo
,
R.
,
Bauthier
,
C.
,
Conti
,
J.
,
Voue
,
M.
, and
De Coninck
,
J.
,
2003
, “
Experimental Investigation of Splash and Crown Formation During Single Drop Impact on Wetted Surfaces
,”
Exp. Fluids
,
35
(
6
), pp.
648
652
.
6.
Gao
,
X.
, and
Li
,
R.
,
2015
, “
Impact of a Single Drop on a Flowing Liquid Film
,”
Phys. Rev. E
,
92
(
5
), p.
053005
.
7.
Lee
,
C. H.
, and
Kim
,
K. C.
,
2014
, “
Impinging Characteristics of Water Droplet on Hot Surface: Effect of Wall Inclination
,”
ASME J. Heat Transfer
,
136
(
8
), p.
080908
.
8.
Wang
,
Z.
,
Lopez
,
C.
,
Hirsa
,
A.
, and
Koratkar
,
N.
,
2007
, “
Impact Dynamics and Rebound of Water Droplets on Superhydrophobic Carbon Nanotube Arrays
,”
Appl. Phys. Lett.
,
91
(
2
), p.
023105
.
9.
Deng
,
T.
,
Varanasi
,
K. K.
,
Hsu
,
M.
,
Bhate
,
N.
,
Keimel
,
C.
,
Stein
,
J.
, and
Blohm
,
M.
,
2009
, “
Nonwetting of Impinging Droplets on Textured Surfaces
,”
Appl. Phys. Lett.
,
94
(
13
), p.
133109
.
10.
Lee
,
J. B.
, and
Lee
,
S. H.
,
2011
, “
Dynamic Wetting and Spreading Characteristics of a Liquid Droplet Impinging on Hydrophobic Textured Surfaces
,”
Langmuir
,
27
(
11
), pp.
6565
6573
.
11.
Alizadeh
,
A.
,
Bahadur
,
V.
,
Zhong
,
S.
,
Shang
,
W.
,
Li
,
R.
,
Ruud
,
J.
,
Yamada
,
M.
,
Ge
,
L.
,
Dhinojwala
,
A.
, and
Sohal
,
M.
,
2012
, “
Temperature Dependent Droplet Impact Dynamics on Flat and Textured Surfaces
,”
Appl. Phys. Lett.
,
100
(
11
), p.
111601
.
12.
Shen
,
J.
,
Graber
,
C.
,
Liburdy
,
J.
,
Pence
,
D.
, and
Narayanan
,
V.
,
2010
, “
Simultaneous Droplet Impingement Dynamics and Heat Transfer on Nano-Structured Surfaces
,”
Exp. Therm. Fluid Sci.
,
34
(
4
), pp.
496
503
.
13.
Lee
,
J. B.
,
Lee
,
S. H.
, and
Choi
,
C. K.
,
2011
, “
Dynamic Spreading of a Droplet Impinging on Micro-Textured Surfaces
,”
ASME J. Heat Transfer
,
133
(
8
), p.
080905
.
14.
Negeed
,
E.-S. R.
,
Albeirutty
,
M.
,
Al-Sharif
,
S. F.
,
Hidaka
,
S.
, and
Takata
,
Y.
,
2016
, “
Dynamic Behavior of a Small Water Droplet Impact Onto a Heated Hydrophilic Surface
,”
ASME J. Heat Transfer
,
138
(
4
), p.
042901
.
15.
Park
,
J. Y.
,
Gardner
,
A.
,
King
,
W. P.
, and
Cahill
,
D. G.
,
2014
, “
Droplet Impingement and Vapor Layer Formation on Hot Hydrophobic Surfaces
,”
ASME J. Heat Transfer
,
136
(
9
), p.
092902
.
16.
Khavari
,
M.
,
Sun
,
C.
,
Lohse
,
D.
, and
Tran
,
T.
,
2015
, “
Fingering Patterns During Droplet Impact on Heated Surfaces
,”
Soft Matter
,
11
(
17
), pp.
3298
3303
.
17.
Li
,
L.
,
Jia
,
X.
,
Liu
,
Y.
, and
Su
,
M.
,
2016
, “
Simulation of Double Droplets Impact on Liquid Film by a Simplified Lattice Boltzmann Model
,”
Appl. Therm. Eng.
,
98
, pp.
656
669
.
18.
Yarin
,
A.
, and
Weiss
,
D.
,
1995
, “
Impact of Drops on Solid Surfaces: Self-Similar Capillary Waves, and Splashing as a New Type of Kinematic Discontinuity
,”
J. Fluid Mech.
,
283
, pp.
141
173
.
19.
Sellers
,
S. M.
, and
Black
,
W.
,
2008
, “
Boiling Heat Transfer Rates for Small Precisely Placed Water Droplets on a Heated Horizontal Plate
,”
ASME J. Heat Transfer
,
130
(
5
), p.
054504
.
20.
Trujillo
,
M. F.
,
Alvarado
,
J.
,
Gehring
,
E.
, and
Soriano
,
G. S.
,
2011
, “
Numerical Simulations and Experimental Characterization of Heat Transfer From a Periodic Impingement of Droplets
,”
ASME J. Heat Transfer
,
133
(
12
), p.
122201
.
21.
Trujillo
,
M. F.
, and
Lewis
,
S. R.
,
2012
, “
Thermal Boundary Layer Analysis Corresponding to Droplet Train Impingement
,”
Phys. Fluids
,
24
(
11
), p.
112102
.
22.
Muthusamy
,
J. P.
,
Zhang
,
T.
,
Alvarado
,
J.
,
Kanjirakat
,
A.
, and
Sadr
,
R.
,
2016
, “
Effects of High Frequency Droplet Train Impingement on Crown Propagation Dynamics and Heat Transfer
,”
ASME J. Heat Transfer
,
138
(
2
), p.
020903
.
23.
Zhang
,
T.
,
Muthusamy
,
J. P.
,
Alvarado
,
J. L.
,
Kanjirakat
,
A.
, and
Sadr
,
R.
,
2016
, “
Numerical and Experimental Investigations of Crown Propagation Dynamics Induced by Droplet Train Impingement
,”
Int. J. Heat Fluid Flow
,
57
, pp.
24
33
.
24.
Zhang
,
T.
,
Alvarado
,
J.
,
Muthusamy
,
J. P.
,
Kanjirakat
,
A.
, and
Sadr
,
R.
,
2016
, “
Effects of High Frequency Droplet Train Impingement on Spreading-Splashing Transition, Film Hydrodynamics, and Heat Transfer
,”
ASME J. Heat Transfer
,
138
(
2
), p.
020902
.
25.
Zhang
,
T.
,
Alvarado
,
J.
,
Muthusamy
,
J. P.
,
Kanjirakat
,
A.
, and
Sadr
,
R.
,
2016
, “
Effects of Screen Laminates on Droplet-Induced Film Hydrodynamics and Surface Heat Transfer
,”
ASME J. Heat Transfer
,
138
(
8
), p.
080902
.
26.
Dunand
,
P.
,
Castanet
,
G.
,
Gradeck
,
M.
,
Lemoine
,
F.
, and
Maillet
,
D.
,
2013
, “
Heat Transfer of Droplets Impinging Onto a Wall Above the Leidenfrost Temperature
,”
C. R. Méc.
,
341
(
1
), pp.
75
87
.
27.
Park
,
J. Y.
,
Min
,
C.-K.
,
Granick
,
S.
, and
Cahill
,
D. G.
,
2012
, “
Residence Time and Heat Transfer When Water Droplets Hit a Scalding Surface
,”
ASME J. Heat Transfer
,
134
(
10
), p.
101503
.
28.
Gradeck
,
M.
,
Seiler
,
N.
,
Ruyer
,
P.
, and
Maillet
,
D.
,
2013
, “
Heat Transfer for Leidenfrost Drops Bouncing Onto a Hot Surface
,”
Exp. Therm. Fluid Sci.
,
47
, pp.
14
25
.
29.
Qiu
,
L.
,
Dubey
,
S.
,
Choo
,
F. H.
, and
Duan
,
F.
,
2015
, “
Splashing of High Speed Droplet Train Impinging on a Hot Surface
,”
Appl. Phys. Lett.
,
107
(
16
), p.
164102
.
30.
Qiu
,
L.
,
Dubey
,
S.
,
Choo
,
F. H.
, and
Duan
,
F.
,
2016
, “
The Transitions of Time-Independent Spreading Diameter and Splashing Angle When a Droplet Train Impinging Onto a Hot Surface
,”
RSC Adv.
,
6
(
17
), pp.
13644
13652
.
You do not currently have access to this content.