Electrostatic rotary bell sprayers (ERBS) are widely used in automotive painting applications. These processes involve complex airflows to shape paint sprays and transport droplets toward automotive parts to be coated. Despite the importance of shaping airflow on global spray characteristics, a detailed characterization of this aerodynamic flow is still missing. For this purpose, an experimental study was conducted on the influence of some ERBS operating parameters on the development and characteristics of shaping airflow. Results show that, for low swirl numbers, the flow behavior is close to that of annular swirling jets and a good agreement is found between ERBS flow characteristics and data available in literature. When rotational speed of the bell cup is sufficiently fast, a change of regime is observed with a shift in the longitudinal flow development and an increase of recirculation zone length. This change of regime is attributed to vortex breakdown instability, known to occur when high swirl strength is beyond a critical value. Experimental results obtained in this study put forward a clear link between the shaping air flow rate and the rotation frequency on the aerodynamics and also provide valuable leads to design shaping air flow in modern ERBS.

References

References
1.
Fan
,
H.-T.
,
Kuo
,
H.
, and
Simmer
,
J.
,
2011
, “
Measuring Paint Droplet Size, Velocity, and Charge-to-Mass Ratio Distribution for Electrostatic Rotary Bell Spray Simulation
,”
ASME
Paper No. IMECE2011-63556.
2.
Salazar
,
A. J.
,
2013
, “
Computational Modeling of Relevant Automotive Rotary Spray Painting Process
,”
Automotive Painting Technology
,
K.
Toda
,
A.
Salazar
, and
K.
Saito
, eds.,
Springer
, Dordrecht, pp.
47
95
.
3.
Ahmed
,
M.
, and
Youssef
,
M. S.
,
2012
, “
Characteristics of Mean Droplet Size Produced by Spinning Disk Atomizers
,”
ASME J. Fluids Eng.
,
134
(
7
), p.
071103
.
4.
Fukuta
,
K.
,
Murate
,
M.
,
Ohashi
,
Y.
, and
Toda
,
K.
,
1993
, “
New Rotary Bell for Metallic Paint Application
,”
Met. Finish.
,
1
, pp.
39
42
.
5.
Corbeels
,
P.
,
Senser
,
D.
, and
Lefebvre
,
A.
,
1992
, “
Atomization Characteristics of a High-Speed Rotary-Bell Paint Applicator
,”
Atomization Sprays
,
2
(2), pp.
87
99
.
6.
Domnick
,
J.
, and
Thieme
,
M.
,
2006
, “
Atomization Characteristics of High-Speed Rotary Bell Atomizers
,”
Atomization Sprays
,
16
(8), pp.
857
874
.
7.
Kazama
,
S.
,
2003
, “
Steady-State Paint Flow Under High Centrifugal Force: Atomization in Spray Painting
,”
JSAE Rev.
,
24
(
4
), pp.
489
494
.
8.
Domnick
,
J.
,
2010
, “
Effect of Bell Geometry in High-Speed Rotary Bell Atomization
,”
ILASS-Europe 2010, 23rd Annual Conference on Liquid Atomization and Spray Systems
.
9.
Ogasawara
,
S.
,
Daikoku
,
M.
,
Shirota
,
M.
,
Inamura
,
T.
,
Saito
,
Y.
,
Yasumura
,
K.
,
Shoji
,
M.
,
Aoki
,
H.
, and
Miura
,
T.
,
2010
, “
Liquid Atomization Using a Rotary Bell Cup Atomizer
,”
J. Fluid Sci. Technol.
,
5
(
3
), pp.
464
474
.
10.
Hicks
,
P. G.
, and
Senser
,
D. W.
,
1995
, “
Simulation of Paint Transfer in an Air Spray Process
,”
ASME J. Fluids Eng.
,
117
(4), pp.
713
719
.
11.
Bauckhage
,
K.
,
Scholz
,
T.
, and
Schulte
,
G.
,
1995
, “
The Influence of Applied High-Voltage on the Atomization Characteristic of a Commercial High-Speed Rotary Atomizer
,”
11th European Conference of ILASS Europe on atomization and sprays
, pp.
337
346
.
12.
Im
,
K.
,
Lai
,
M.
,
Liu
,
Y.
,
Sankagiri
,
N.
,
Loch
,
T.
, and
Nivi
,
H.
,
2001
, “
Visualization and Measurement of Automotive Electrostatic Rotary-Bell Paint Spray Transfer Processes
,”
ASME J. Fluids Eng.
,
123
(
2
), pp.
237
245
.
13.
Akafuah
,
N. K.
,
Salazar
,
A. J.
, and
Saito
,
K.
,
2009
, “
Infrared Visualization of Automotive Paint Spray Transfer Process
,”
ASME
Paper No. FEDSM2009-78033.
14.
Tachi
,
K.
,
Yamada
,
K.
,
Okuda
,
C.
, and
Suzuki
,
S.
,
1987
, “
Study on Paint Coating by Electrostatic Rotary Atomizer (iv)—Effects of Shaping Air on Paint Particle Flow
,”
Shikizai Kyokai-shi (Japan)
,
60
(
6
), pp.
321
327
.
15.
Honma
,
K.
, and
Yamasaki
,
I.
,
1999
, “
A Plurality of Shaping Air Nozzles for Expelling Shaping Air at a Predetermined Pressure and Flow Amount for Use in Metallic Paint Coating
,” U.S. Patent No. 5,980,994.
16.
Matsuyama
,
K.
,
Igarasi
,
T.
,
Shirota
,
M.
,
Inamura
,
T.
,
Yasumura
,
K.
,
Saito
,
Y.
,
Matsusita
,
Y.
,
Aoki
,
H.
,
Miura
,
T.
,
Ogasawara
,
S.
, and
Daikoku
,
M.
,
2009
, “
Effect of Shaping Air Nozzle Shape on Spray Characteristics of Rotary Bell-Cup Atomizer
,”
18th ILASS-Japan Symposium Program
, ILASS-Asia [in Japanese]
.
17.
Rajaratnam
,
N.
,
1976
,
Turbulent Jets
(Developments in Water Science),
Elsevier
, Amsterdam.
18.
Uyttendaele
,
M.
, and
Shambaugh
,
R.
,
1989
, “
The Flow Field of Annular Jets at Moderate Reynolds Numbers
,”
Ind. Eng. Chem. Res.
,
28
(
11
), pp.
1735
1740
.
19.
Wygnanski
,
I.
, and
Fiedler
,
H.
,
1969
, “
Some Measurements in the Self-Preserving Jet
,”
J. Fluid Mech.
,
38
(
3
), pp.
577
612
.
20.
Aly
,
M.
, and
Rashed
,
M.
,
1991
, “
Experimental Investigation of an Annular Jet
,”
J. Wind Eng. Indus. Aerodyn.
,
37
(
2
), pp.
155
166
.
21.
Ko
,
N. W. M.
, and
Chan
,
W. T.
,
1978
, “
Similarity in Initial Region of Annular Jets—Three Configurations
,”
J. Fluid Mech.
,
84
(
4
), pp.
641
656
.
22.
Kuhlman
,
J.
,
1987
, “
Variation of Entrainment in Annular Jets
,”
AIAA J.
,
25
(
3
), pp.
373
379
.
23.
Danlos
,
A.
,
Lalizel
,
G.
, and
Patte-Rouland
,
B.
,
2013
, “
Experimental Characterization of the Initial Zone of an Annular Jet With a Very Large Diameter Ratio
,”
Exp. Fluids
,
54
(
1
), pp.
1
17
.
24.
Li
,
K.
, and
Tankin
,
R.
,
1987
, “
A Study of Cold and Combusting Flow Around Bluff-Body Combustors
,”
Combust. Sci. Technol.
,
52
(
4–6
), pp.
173
206
.
25.
Carmody
,
T.
,
1964
, “
Establishment of the Wake Behind a Disk
,”
ASME J. Basic Eng.
,
86
(4), pp.
869
880
.
26.
Chigier
,
N.
, and
Beér
,
J.
,
1964
, “
The Flow Region Near the Nozzle in Double Concentric Jets
,”
ASME J. Fluids Eng.
,
86
(
4
), pp.
797
804
.
27.
Davies
,
T.
, and
Beér
,
J.
,
1971
, “
Flow in the Wake of Bluff-Body Flame Stabilizers
,”
Symp. (Int.) Combust.
,
13
(
1
), pp.
631
638
.
28.
Durao
,
D.
, and
Whitelaw
,
J.
,
1978
, “
Velocity Characteristics of the Flow in the Near Wake of a Disk
,”
J. Fluid Mech.
,
85
(
2
), pp.
369
385
.
29.
Taglia
,
C. D.
,
2003
, “
Numerical Investigation of the Non-Reacting Unsteady Flow Behind a Disk Stabilized Burner With Large Blockage
,” Ph.D. thesis, Technische Wissenschaften ETH, Zürich.
30.
Stroomer
,
P.
,
1995
, “
Turbulence and OH Structure in Flames
,” Ph.D. thesis, Delft University, Delft, The Netherlands.
31.
Taglia
,
C. D.
,
Blum
,
L.
,
Gass
,
J.
,
Ventikos
,
Y.
, and
Poulikakos
,
D.
,
2004
, “
Numerical and Experimental Investigation of an Annular Jet Flow With Large Blockage
,”
ASME J. Fluids Eng.
,
126
(
3
), pp.
375
384
.
32.
Lucca-Negro
,
O.
, and
O'Doherty
,
T.
,
2001
, “
Vortex Breakdown: A Review
,”
Prog. Energy Combust. Sci.
,
27
(
4
), pp.
431
481
.
33.
Billant
,
P.
,
Chomaz
,
J.
, and
Huerre
,
P.
,
1998
, “
Experimental Study of Vortex Breakdown in Swirling Jets
,”
J. Fluid Mech.
,
376
(
1
), pp.
183
219
.
34.
Sheen
,
H.
,
Chen
,
W.
, and
Jeng
,
S.
,
1996
, “
Recirculation Zones of Unconfined and Confined Annular Swirling Jets
,”
AIAA J.
,
34
(
3
), pp.
572
579
.
35.
O'Connor
,
J.
, and
Lieuwen
,
T.
,
2012
, “
Recirculation Zone Dynamics of a Transversely Excited Swirl Flow and Flame
,”
Phys. Fluids
,
24
(
7
), p.
075107
.
36.
Chigier
,
N. A.
, and
Chervinsky
,
A.
,
1967
, “
Experimental Investigation of Swirling Vortex Motion in Jets
,”
ASME J. Appl. Mech.
,
34
(2), pp.
443
451
.
37.
Andersson
,
B.
,
Golovitchev
,
V.
,
Jakobsson
,
S.
,
Mark
,
A.
,
Edelvik
,
F.
,
Davidson
,
L.
, and
Carlson
,
J. S.
,
2013
, “
A Modified Tab Model for Simulation of Atomization in Rotary Bell Spray Painting
,”
J. Mech. Eng. Autom.
,
3
(
2
), pp.
54
61
.
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