An interesting feature of jets from liquid-liquid coaxial swirl atomizers used in bipropellant rockets or elsewhere is that the outer jet results in a tulip shaped liquid bulb even at operating pressure levels. In this context, experiments have been performed to study the discharge and tulip characteristics of annular jets through qualitative simulation of outer jet flow conditions at which tulip bulb prevails. It is shown that the discharge coefficient increases steeply with Reynolds number, a trend which is distinct from that of circular orifices. The range of flow conditions at which tulip bulb prevails decreases with the annular gap. If a swirl component is introduced into the annular jet, it alters the discharge characteristics and the tulip range with a tendency to form multiple tulips. Variation of tulip length for different annular gaps shows a common trend when plotted against liquid flow rate. The experimental data of tulip length agree reasonably with the theoretical model reported in literature.

1.
Amagai, K., and Arai, M., 1994, “Disintegration Process of a Liquid Jet Injected from a Coaxial Dual Nozzle,” ICLASS-94, July, pp. 71–78.
2.
Baird
M. H. I.
, and
Davidson
J. F.
,
1962
, “
Annular Jets-I (Fluid Dynamics)
,”
Chemical Engineering Science
, Vol.
17
, pp.
467
472
.
3.
Beer, J. M., and Chigier, N., 1983, Combustion Aerodynamics, Robert E. Krieger Publishing Company.
4.
Binnie
A. H.
, and
Squire
H. B.
,
1941
, “
Liquid Jets of Annular Cross-Section
,”
The Engineer
, Vol.
171
, London, pp.
236
238
.
5.
Boussinesq
J.
,
1869
, “
Theorie des experiences de Savart sur la frome que prend une veine liquide apres s’etre choquee contre un plan circulaire
,”
Comptes Rendus de l’Academie des Sciences
, Vol.
69
, pp.
128
131
.
6.
Care, I., and Ledoux, M., 1991 “Study of an Airblast Coaxial Atomizer: Experiments and Modelisation,” Proceedings of the 5th International Conference on Liquid Atomization and Spraying Systems (ILASS), Gaithersburg, MD, pp. 763–770 (Paper 85).
7.
Chuech
S. G.
,
1993
, “
Numerical Simulation of Nonswirling and Swirling Annular Liquid Jets
,”
AIAA Journal
, Vol.
31
, June, pp.
1022
1027
.
8.
Esser
P. D.
, and
Abdel-Khalik
S. I.
,
1984
, “
Dynamics of Vertical Annular Liquid Jets
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
106
, pp.
45
51
.
9.
Hardalupas
Y.
, and
Whitelaw
J. H.
,
1994
, “
Characteristics of Sprays Produced by Coaxial Airblast Atomizers
,”
Journal of Propulsion and Power
, Vol.
10
, No.
4
, July–Aug, pp.
453
460
.
10.
Hasegawa
T.
,
Suganuma
M.
, and
Watanabe
H.
,
1997
, “
Anomaly of Excess Pressure Drops of the Flow Through Very Small Orifices
,”
Physics of Fluids
, Vol.
9
, Jan., pp.
1
3
.
11.
Hoffman
M. A.
,
Takahashi
R. K.
, and
Monson
R. D.
,
1980
, “
Annular Liquid Jet Experiments
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
102
, pp.
344
349
.
12.
Kihm
K. D.
, and
Chigier
N. A.
,
1990
, “
Experimental Investigations of Annular Liquid Curtains
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
112
, Mar., pp.
61
66
.
13.
Lance
G. N.
, and
Perry
R. L.
,
1953
, “
Water Bells
,”
Proceedings of the Physical Society
, London, Series B, Vol.
66
, pp.
1067
1072
.
14.
Moffat, R. J., 1988, “Describing the Uncertainties in Experimental Results,” Experimental Thermal and Fluid Science, No. 1, pp. 3–17.
15.
Parlange
J. Y.
,
1967
, “
A Theory of Water-bells
,”
Journal of Fluid Mechanics
, Vol.
29
, Part 2, pp.
361
372
.
16.
Ramamurthi
K.
, and
John Tharakan
T.
,
1995
, “
Experimental Study of Liquid Sheets Formed in Coaxial Swirl Injectors
,”
Journal of Propulsion and Power
, Vol.
11
, No.
6
, Nov–Dec, pp.
1103
1109
.
17.
Ramos
J. I.
,
1988
, “
Liquid Curtains: I Fluid Mechanics
,”
Chemical Engineering Science
, Vol.
43
, No.
12
, pp.
3174
3184
.
18.
Ramos
J. I.
,
1990
, “
Analytical, Asymptotic and Numerical Studies of Liquid Curtains and Comparisons with Experimental Data
,”
Applied Mathematical Modelling
, Vol.
14
, Apr., pp.
170
183
.
19.
Sankar, S. V., Brena de la Rosa, A., Isakovic, A., and Bachalo, W. D., 1991, “Liquid Atomization by Co-axial Rocket Injectors,” AIAA Paper 91-0691, Jan.
20.
Sivakumar
D.
, and
Raghunandan
B. N.
,
1996
, “
Jet Interaction in Liquid-Liquid Coaxial Injectors
,”
ASME JOURNAL OF FLUIDS ENGINEERING
, Vol.
118
, June, pp.
329
334
.
21.
Taylor
G. I.
,
1959
, “
The Dynamics of Thin Sheets of Fluid. 1. Water Bells
,”
Proceedings of the Royal Society
, Series A, Vol.
253
, pp.
289
295
.
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