The objective of this study is to develop a theoretical basis for scalability considerations and design of a large-scale combustor utilizing flow blurring (FB) atomization. FB atomization is a recently discovered twin-fluid atomization concept, reported to produce fine spray of liquids with wide range of viscosities. Previously, we have developed and investigated a small-scale swirl-stabilized combustor of 7-kWth capacity. Spray measurements have shown that the FB injector's atomization capability is superior when compared to other techniques, such as air blast atomization. However, despite these favorable results, scalability of the FB injector and associated combustor design has never been explored for large capacity; for example, for gas turbine applications. In this study, a number of dimensionless scaling parameters that affect the processes of atomization, fuel–air mixing, and combustion are analyzed, and scaling criteria for the different components of the combustion system are selected. Constant velocity criterion is used to scale key geometric components of the system. Scaling of the nonlinear dimensions and complex geometries, such as swirler vanes and internal parts of the injector is undertaken through phenomenological analysis of the flow processes associated with the scaled component. A scaled-up 60-kWth capacity combustor with FB injector is developed and investigated for combustion performance using diesel and vegetable oil (VO) (soybean oil) as fuels. Results show that the scaled-up injector's performance is comparable to the smaller scale system in terms of flame quality, emission levels, and static flame stability. Visual flame images at different atomizing air-to-liquid ratio by mass (ALR) show mainly blue flames, especially for ALR > 2.8. Emission measurements show a general trend of lower CO and NOx levels at higher ALRs, replicating the performance of the small-scale combustion system. Flame liftoff height at different ALRs is similar for both scales. The scaled-up combustor with FB injector preformed robustly with uncompromised stability for the range of firing rates (FRs) above 50% of the design capacity. Experimental results corroborate with the scaling methodology developed in this research.

References

References
1.
Lefebvre
,
A. H.
,
1989
,
Atomization and Sprays
,
Hemisphere
,
New York
.
2.
Kreith
,
F.
,
2000
,
Fluid Mechanics
,
CRC Press
,
Boca Raton, FL
.
3.
Lefebvre
,
A. H.
,
Wang
,
X. F.
, and
Martin
,
C. A.
,
1988
, “
Spray Characteristics of Aerated-Liquid Pressure Atomizers
,”
J. Propul. Power
,
4
(
4
), pp.
293
298
.
4.
Sovani
,
S. D.
,
Sojka
,
P. E.
, and
Lefebvre
,
A. H.
,
2001
, “
Effervescent Atomization
,”
Prog. Energy Combust. Sci.
,
27
(
4
), pp.
483
521
.
5.
Gañán-Calvo
,
A. M.
,
2005
, “
Enhanced Liquid Atomization: From Flow-Focusing to Flow-Blurring
,”
Appl. Phys. Lett.
,
86
(
21
), p.
214101
.
6.
Simmons
,
B. M.
,
Kolhe
,
P. S.
,
Taylor
,
R. P.
, and
Agrawal
,
A. K.
,
2010
, “
Glycerol Combustion Using Flow-Blurring Atomization
,”
Technical Meeting of the Central States Section of the Combustion Institute
, Champaign, IL, Mar. 21–23.
7.
Simmons
,
B. M.
, and
Agrawal
,
A. K.
,
2011
, “
Drop Size and Velocity Measurements in Bio-Oil Sprays Produced by the Flow-Blurring Injector
,”
ASME
Paper No. GT2011-46832.
8.
Panchasara
,
H. V.
,
Sequera
,
D. E.
,
Schreiber
,
W. C.
, and
Agrawal
,
A. K.
,
2009
, “
Emissions Reductions in Diesel and Kerosene Flames Using a Novel Fuel Injector
,”
J. Propul. Power
,
25
(
4
), pp.
984
987
.
9.
Simmons
,
B. M.
, and
Agrawal
,
A. K.
,
2010
, “
Spray Characteristics of a Flow-Blurring Atomizer
,”
Atomization Sprays
,
20
(
9
), pp.
821
835
.
10.
Simmons
,
B. M.
, and
Agrawal
,
A. K.
,
2012
, “
Flow Blurring Atomization for Low-Emission Combustion Of Liquid Biofuels
,”
Combust. Sci. Technol.
,
184
(
5
), pp.
660
675
.
11.
Simmons
,
B. M.
,
Panchasara
,
H. V.
, and
Agrawal
,
A. K.
,
2009
, “
A Comparison of Air-Blast and Flow-Blurring Injectors Using Phase Doppler Particle Analyzer Technique
,”
ASME
Paper No. GT2009-60239.
12.
Bohon
,
M. D.
,
Metzger
,
B. A.
,
Linak
,
W. P.
,
King
,
C. J.
, and
Roberts
,
W. L.
,
2011
, “
Glycerol Combustion and Emissions
,”
Proc. Combust. Inst.
,
33
(
2
), pp.
2717
2724
.
13.
Kenny
,
R. J.
,
Moser
,
M. D.
,
Hulka
,
J.
, and
Jones
,
G.
,
2006
, “
Cold Flow Testing for Liquid Propellant Rocket Injector Scaling and Throttling
,”
AIAA
Paper No. 2006-4705.
14.
Jiang
,
X.
,
Siamas
,
G. A.
,
Jagus
,
K.
, and
Karayiannis
,
T. G.
,
2010
, “
Physical Modelling and Advanced Simulations of Gas–Liquid Two-Phase Jet Flows in Atomization and Sprays
,”
Prog. Energy Combust. Sci.
,
36
(
2
), pp.
131
167
.
15.
Rosner
,
D. E.
,
2012
,
Transport Processes in Chemically Reacting Flow Systems
,
Courier Dover
,
Mineola, NY
.
16.
Baukal
,
C. E.
,
2004
,
Industrial Burner's Handbook
,
CRC Press
,
Boca Raton, FL
, p.
195
.
17.
Kumar
,
S.
,
Paul
,
P. J.
, and
Mukunda
,
H. S.
,
2005
, “
Investigations of the Scaling Criteria for a Mild Combustion Burner
,”
Proc. Combust. Inst.
,
30
(
2
), pp.
2613
2621
.
18.
Weber
,
R.
,
1996
, “
Scaling Characteristics of Aerodynamics, Heat Transfer, and Pollutant Emissions in Industrial Flames
,”
Symp. (Int.) Combust.
,
26
(
2
), pp.
3343
3354
.
19.
Jiang
,
L.
,
Agrawal
,
A. K.
, and
Taylor
,
R. P.
,
2014
, “
High Speed Visualization and PIV Measurements in the Near Field of Spray Produced by Flow-Blurring Atomization
,”
ASME
Paper No. GT2014-27199.
20.
Shepard
,
T. G.
, (
2011
), “
Bubble Size Effect on Effervescent Atomization
,” Doctoral dissertation, University of Minnesota, Minneapolis, MN.
21.
Simmons
,
B. M.
,
2011
, “
Atomization and Combustion of Liquid Biofuels
,” Doctoral dissertation, Mechanical Engineering Department, University of Alabama, Tuscaloosa, AL.
22.
Gupta
,
A. K.
,
Lilley
,
D. G.
, and
Syred
,
N.
,
1984
.
Swirl Flows
,
Abacus Press
,
Tunbridge Wells, UK
.
23.
Syred
,
N.
, and
Beer
,
J. M.
,
1974
, “
Combustion in Swirling Flows: A Review
,”
Combust. Flame
,
23
(
2
), pp.
143
201
.
24.
Jiang
,
L.
,
Agrawal
,
A. K.
, and
Taylor
,
R. P.
,
2014
, “
Clean Combustion of Different Liquid Fuels Using a Novel Injector
,”
Exp. Therm. Fluid Sci.
,
57
, pp.
275
284
.
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