An experimental investigation was conducted to study the effects of increased ambient pressure (up to $6.89MPa$) and increased nozzle pressure drop (up to $2.8MPa$) on the cone angles for sprays produced by pressure-swirl atomizers having varying amounts of initial swirl. This study extends the classical results of DeCorso and Kemeny, (1957, “Effect of Ambient and Fuel Pressure on Nozzle Spray Angle,” ASME Transactions, 79(3), pp. 607–615). Shadow photography was used to measure cone angles at $x∕D0=10$, 20, 40, and 60. Our lower pressure results for atomizer swirl numbers of 0.50 and 0.25 are consistent with those of DeCorso and Kemeny, who observed a decrease in cone angle with an increase in nozzle pressure drop, $ΔP$, and ambient density, $ρair$, until a minimum cone angle was reached when $ΔPρair1.6∼100MPa(kg∕m3)1.6$ (equivalent to $200psi(lbm∕ft3)1.6$). Results for atomizers having higher initial swirl do not match the DeCorso and Kemeny results as well, suggesting that their correlation be used with caution. Another key finding is that an increase in $ΔPρair1.6$ to a value of $600MPa(kg∕m3)1.6$ leads to continued decrease in cone angle, but that a subsequent increase to $2000MPa(kg∕m3)1.6$ has little effect on cone angle. Finally, there was little effect of nozzle pressure drop on cone angle, in contrast to findings of previous workers. These effects are hypothesized to be due to gas entrainment.

1.
DeCorso
,
D. E.
, and
Kemeny
,
G. A.
, 1957, “
Effect of Ambient and Fuel Pressure on Nozzle Spray Angle
,”
Trans. ASME
0097-6822,
79
(
3
), pp.
607
615
.
2.
Ortman
,
J.
, and
Lefebvre
,
A. H.
, 1985, “
Fuel Distributions from Pressure-Swirl Atomizers
,”
J. Propul. Power
0748-4658,
1
(
1
), pp.
11
15
.
3.
Preussner
,
C.
,
Döring
,
C.
,
Fehler
,
S.
, and
Kampmann
,
S.
, 1998, “
GDI: Interaction Between Mixture Preparation, Combustion System and Injector Performance
,” SAE Technical Paper No. 980498.
4.
Satapathy
,
M. R.
, 1997, “
The Effect of Ambient Density on the Performance of an Effervescent Diesel Injector: A Thesis
,” MSME thesis, Purdue University, West Lafayette.
5.
Zeaton
,
G. W. P.
, 2004, “
An Experimental Study of Supercritical Fluid Jets: A Thesis
,” MSME thesis, Purdue University, West Lafayette.
6.
Syred
,
N.
,
Gupta
,
A. K.
, and
Beer
,
J. M.
, 1954, “
Temperature and Density Gradient Changes Arising With the Processing Vortex Core and Vortex Breakdown in Swirl Burners
,”
15th Symposium (International) on Combustion
, pp.
587
597
.
7.
Lefebvre
,
A. H.
, 1989,
Atomization and Sprays
,
Hemisphere
,
New York
.
8.
Ohrn
,
T. R.
, 1989, “
The Effects of Internal Geometry and Injection Pressure on the Flow and Spray Characteristics of a Plain Orifice Atomizer: A Thesis
,” MSME thesis, Purdue University, West Lafayette.
9.
Dodge
,
L. G.
, and
Biaglow
,
J. A.
, 1986, “
Effect of Elevated Temperature and Pressure on Sprays From Simplex Swirl Atomizers
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
108
, pp.
209
215
.
10.
Jang
,
C.
,
Bae
,
C.
, and
Choi
,
C.
, 2000, “
Characterization of Prototype High-Pressure Swirl Injector Nozzles—Part I: Prototype Development and Initial Characterization of Sprays
,”
Atomization Sprays
1044-5110,
10
, pp.
159
178
.
11.
Chen
,
S. K.
,
Lefebvre
,
A. H.
, and
Rollbuhler
,
J.
, 1992, “
Factors Influencing the Effective Spray Cone Angle of Pressure Swirl Atomizers
,”
ASME J. Eng. Gas Turbines Power
0742-4795,
114
, pp.
97
103
.
12.
Kline
,
S. J.
, and
McClintock
,
F. A.
, 1953, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng. (Am. Soc. Mech. Eng.)
0025-6501,
75
, pp.
3
9
.
13.
Wang
,
X. F.
, and
Lefebvre
,
A. H.
, 1987, “
Influence of Ambient Air Pressure on Pressure-Swirl Atomization
,” ASME Paper No. 87-GT-55.
14.
Parsons
,
J. A.
, and
Jasuja
,
A. K.
, 1986, “
Effect of Air Pressure Upon Spray Angle∕Width Characteristics of Simplex Pressure Swirl Atomizers
,” ASME Paper No. 88-GT-176.