Abstract

The effect of lip thickness of fuel nozzle on the liftoff of an attached diffusion methane flame with and without a coflow was experimentally and analytically investigated. Three fuel nozzles made of a long pipe with the same internal diameter but different nozzle lip thickness were tested. The co-airflow was also varied to assess its impact on the liftoff of jet diffusion flame. The results showed that the effect of fuel nozzle lip thickness on the liftoff of a free jet flame (i.e., no coflow) is marginal. However, the presence of a weak to moderate coflow (0.05 m/s < Uco < 0.3 m/s) reduced the liftoff velocity of an attached flame. The reduction rate of the liftoff velocity with co-airflow was found to be more significant for the fuel nozzle with the smaller lip thickness. At a relatively higher coflow (Uco > ∼0.3 m/s), a more pronounced drop in the liftoff velocity with coflow was observed. Flow field characteristics obtained using PIV measurements showed that the coflow stream experienced a transition to the turbulent regime for Uco > ∼0.3 m/s range which is believed to cause the inception of the flame liftoff to occur. A model for predicting the liftoff velocity of an attached flame in the presence of a coflow was developed based on the stoichiometric mixture velocity equation. This model showed good agreement with the present experimental data. However, although it can predict successfully the observed trends in the literature, further experiments are required to generalize it.

References

References
1.
Akbarzadeh
,
M.
, and
Birouk
,
M.
,
2015
, “
On the Hysteresis Phenomenon of Turbulent Lifted Diffusion Methane Flame
,”
Flow Turbul. Combust.
,
94
(
3
), pp.
479
493
. 10.1007/s10494-014-9573-1
2.
Chung
,
S. H.
,
2007
, “
Stabilization, Propagation and Instability of Tribrachial Triple Flames
,”
Proc. Combust. Inst.
,
31
(
1
), pp.
877
892
. 10.1016/j.proci.2006.08.117
3.
Coats
,
C. M.
, and
Zhao
,
H.
,
1989
, “
Transition and Stability of Turbulent Jet Diffusion Flames
,”
Proc. Combust. Inst.
,
22
(
1
), pp.
685
692
. 10.1016/S0082-0784(89)80076-1
4.
Eickhoff
,
H.
,
Lenze
,
B.
, and
Leuckel
,
W.
,
1985
, “
Experimental Investigation on the Stabilization Mechanism of Jet Diffusion Flames
,”
Proc. Combust. Inst.
,
20
(
1
), pp.
311
318
. 10.1016/S0082-0784(85)80516-6
5.
Iyogun
,
C. O.
, and
Birouk
,
M.
,
2008
, “
Effect of Fuel Nozzle Geometry on the Stability of a Turbulent Jet Methane Flame
,”
Combust. Sci. Technol.
,
180
(
12
), pp.
2186
2209
. 10.1080/00102200802414980
6.
Lamige
,
S.
,
Lyons
,
K. M.
,
Galizzi
,
C.
,
André
,
F.
,
Kühni
,
M.
, and
Escudié
,
D.
,
2014
, “
Burner Lip Temperature and Stabilization of a Non-Premixed Jet Flame
,”
Exp. Therm. Fluid Sci.
,
56
, pp.
45
52
. 10.1016/j.expthermflusci.2013.11.008
7.
Langman
,
A. S.
,
Nathan
,
G. J.
,
Mi
,
J.
, and
Ashman
,
P. J.
,
2007
, “
The Influence of Geometric Nozzle Profile on the Global Properties of a Turbulent Diffusion Flame
,”
Proc. Combust. Inst.
,
31
(
1
), pp.
1599
1607
. 10.1016/j.proci.2006.07.165
8.
Otakeyama
,
Y.
,
Yokomori
,
T.
, and
Mizomoto
,
M.
,
2009
, “
Stability of CH4–N2/Air Jet Diffusion Flame for Various Burner Rim Thicknesses
,”
Proc. Combust. Inst.
,
32
(
1
), pp.
1091
1097
. 10.1016/j.proci.2008.05.002
9.
Savas
,
O.
, and
Gollahalli
,
S. R.
,
1986
, “
Flow Structure in Near-Nozzle Region of Gas Jet Flames
,”
AIAA J.
,
24
(
7
), pp.
1137
1140
. 10.2514/3.9404
10.
Takahashi
,
F.
, and
Schmoll
,
W. J.
,
1991
, “
Lifting Criteria of Jet Diffusion Flames
,”
Proc. Combust. Inst.
,
23
(
1
), pp.
677
683
. 10.1016/S0082-0784(06)80316-4
11.
Hutchins
,
A. R.
,
Kribs
,
J. D.
, and
Lyons
,
K. M.
,
2015
, “
Effects of Diluents on Lifted Turbulent Methane and Ethylene Jet Flames
,”
ASME J. Energy Resour. Technol
,
137
(
3
), p.
032204
. 10.1115/1.4028865
12.
Lee
,
B. J.
, and
Chung
,
S. H.
,
1997
, “
Stabilization of Lifted Tribrachial Flames in a Laminar Nonpremixed Jet
,”
Combust. Flame
,
109
(
1–2
), pp.
163
172
. 10.1016/S0010-2180(96)00145-9
13.
Weiland
,
N. T.
, and
Strakey
,
P. A.
,
2009
, “
Stability Characteristics of Turbulent Hydrogen Dilute Diffusion Flames
,”
Combust. Sci. Technol.
,
181
(
5
), pp.
756
781
. 10.1080/00102200902857781
14.
Cessou
,
A.
,
Maurey
,
C.
, and
Stepowski
,
D.
,
2004
, “
Parametric and Statistical Investigation of the Behavior of a Lifted Flame Over a Turbulent Free-Jet Structure
,”
Combust. Flame
,
137
(
4
), pp.
458
477
. 10.1016/j.combustflame.2004.03.005
15.
Kim
,
K. N.
,
Won
,
S. H.
, and
Chung
,
S. H.
,
2007
, “
Characteristics of Turbulent Lifted Flames in Coflow Jets With Initial Temperature Variation
,”
Proc. Combust. Inst.
,
31
(
1
), pp.
1591
1598
. 10.1016/j.proci.2006.07.236
16.
Lamige
,
S.
,
Min
,
J.
,
Galizzi
,
C.
,
André
,
F.
,
Baillot
,
F.
,
Escudié
,
D.
, and
Lyons
,
K. M.
,
2013
, “
On Preheating and Dilution Effects in Non-Premixed Jet Flame Stabilization
,”
Combust. Flame
,
160
(
6
), pp.
1102
1111
. 10.1016/j.combustflame.2013.01.026
17.
Takeno
,
T.
, and
Kotani
,
Y.
,
1975
, “
An Experimental Study on the Stability of Jet Diffusion Flame
,”
Acta Astronaut.
,
2
(
11–12
), pp.
999
1008
. 10.1016/0094-5765(75)90077-6
18.
Scholefield
,
D. A.
, and
Garside
,
J. F.
,
1949
, “
The Structure and Stability of Diffusion Flames
,”
Proc. Combust. Inst.
,
3
(
1
), pp.
102
110
.
19.
Chung
,
S. H.
, and
Lee
,
B. J.
,
1991
, “
On the Characteristics of Laminar Lifted Flames in a Nonpremixed Jet
,”
Combust. Flame
,
86
(
1–2
), pp.
62
72
. 10.1016/0010-2180(91)90056-H
20.
Kalghatgi
,
G. T.
,
1984
, “
Lift-Off Heights and Visible Lengths of Vertical Turbulent Jet Diffusion Flames in Still Sir
,”
Combust. Sci. Technol.
,
41
(
1–2
), pp.
17
29
. 10.1080/00102208408923819
21.
Cheng
,
T. S.
, and
Chiou
,
C. R.
,
2009
, “
Experimental Investigation on the Characteristics of Turbulent Hydrogen Jet Flames
,”
Combust. Sci. Technol.
,
136
(
1–6
), pp.
81
94
.
22.
Terry
,
S. D.
, and
Lyons
,
K. M.
,
2005
, “
Low Reynolds Number Turbulent Lifted Flames in High Co-Flow
,”
Combust. Sci. Technol.
,
177
(
7
), pp.
2091
2112
. 10.1080/00102200500240489
23.
Kumar
,
S.
,
Paul
,
P.
, and
Mukunda
,
H.
,
2007
, “
Prediction of Flame Liftoff Height of Diffusion/Partially Premixed Jet Flames and Modeling of Mild Combustion Burners
,”
Combust. Sci. Technol.
,
179
(
10
), pp.
2219
2253
. 10.1080/00102200701407887
24.
Chao
,
Y.
,
Chang
,
Y.
,
Wu
,
C.
, and
Cheng
,
T.
,
2000
, “
An Experimental Investigation of the Blowout Process of a Jet Flame
,”
Proc. Combust. Inst.
,
28
(
1
), pp.
335
342
. 10.1016/S0082-0784(00)80228-3
25.
Leung
,
T.
, and
Wierzba
,
I.
,
2009
, “
The Effect of Co-Flow Stream Velocity on Turbulent Non-Premixed Jet Flame Stability
,”
Proc. Combust. Inst.
,
32
(
2
), pp.
1671
1678
. 10.1016/j.proci.2008.06.071
26.
Fernández
,
E.
,
Kurdyumov
,
V.
, and
Liñán
,
A.
,
2000
, “
Diffusion Flame Attachment and Lift-Off in the Near Wake of a Fuel Injector
,”
Proc. Combust. Inst.
,
28
(
2
), pp.
2125
2131
. 10.1016/S0082-0784(00)80622-0
27.
Feikema
,
D.
,
Chen
,
R.
, and
Driscoll
,
J.
,
1990
, “
Enhancement of Flame Blowout Limits by the Use of Swirl
,”
Combust. Flame
,
80
(
2
), pp.
183
195
. 10.1016/0010-2180(90)90126-C
28.
Chen
,
Y.
,
Chang
,
C.
,
Pan
,
K.-L.
, and
Yang
,
J.-T.
,
1998
, “
Flame Lift-Off and Stabilization Mechanisms of Nonpremixed Jet Flames on a Bluff-Body Burner
,”
Combust. Flame
,
115
(
1–2
), pp.
51
65
. 10.1016/S0010-2180(97)00336-2
29.
Terry
,
S. D.
, and
Lyons
,
K. M.
,
2006
, “
Turbulent Lifted Flames in the Hysteresis Regime and the Effects of Coflow
,”
ASME J. Energy Resour. Technol.
,
128
(
4
), pp.
319
324
. 10.1115/1.2358147
30.
Brown
,
C. D.
,
Watson
,
K. A.
, and
Lyons
,
K. M.
,
1999
, “
Studies on Lifted Jet Flames in Coflow: The Stabilization Mechanism in the Near- and Far-Fields
,”
Flow Turbul. Combust.
,
62
(
3
), pp.
249
273
. 10.1023/A:1009925500084
31.
Muñiz
,
L.
,
Mungal
,
M. G.
,
Iiz
,
L. M. I.
, and
Muniz
,
L.
,
1997
, “
Instantaneous Flame-Stabilization Velocities in Lifted-Jet Diffusion Flames
,”
Combust. Flame
,
111
(
1–2
), pp.
16
31
. 10.1016/S0010-2180(97)00096-5
32.
Han
,
D.
, and
Mungal
,
M. G.
,
2000
, “
Observations on the Transition From Flame Liftoff to Flame Blowout
,”
Proc. Combust. Inst.
,
28
(
1
), pp.
537
543
. 10.1016/S0082-0784(00)80253-2
33.
Bilger
,
R.
,
1989
, “
The Structure of Turbulent Nonpremixed Flames
,”
Proc. Combust. Inst.
,
22
(
1
), pp.
475
488
. 10.1016/S0082-0784(89)80054-2
34.
Kim
,
M. K.
,
Won
,
S. H.
, and
Chung
,
S. H.
,
2007
, “
Effect of Velocity Gradient on Propagation Speed of Tribrachial Flames in Laminar Coflow Jets
,”
Proc. Combust. Inst.
,
31
(
1
), pp.
901
908
. 10.1016/j.proci.2006.07.238
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