The present work is an experimental investigation that aims at studying the effects of different fuel additives on the soot volume fraction and temperature in a well-defined vertical laminar diffusion flame configuration, and these additives include a diluent (argon) that suppresses the formation of soot and a soot promoter (acetylene) that accelerates and intensifies the soot formation. Three different measuring techniques are employed throughout the whole experimental program, namely, a high-resolution digital camera (up to 3.7 fps) for flame visualization, a bare wire Pt/Pt-13% rhodium fine thermocouple of 15 µm wire diameter for measuring the mean gas temperature inside the flame region and a laser system for measuring the in-flame soot volume fraction. The results indicated that the soot inception zone (deep dark parabolic shape) occurs at the immediate vicinity of the burner. The soot oxidation zone is characterized by high luminosity, and it begins after the fuel is largely consumed. The increased percentages of acetylene in the fuel mixture would lead to extending the length of this zone to ultimately occupy the whole visible flame length, where the luminosity becomes independent of the amount of soot. The temperature within the soot surface growth zone (orange color) continues increasing but at a lower rate that reflects the domination of diffusion combustion mode. Limited partial oxidation may be anticipated within this zone due to the relatively high temperature, which is not high enough to cause luminosity of the soot particles.

References

References
1.
El-Leathy
,
A. M.
,
Kim
,
C. H.
, and
Faeth
,
G. M.
,
2004
, “
Soot Surface Reactions in High-Temperature Laminar Diffusion Flames
,”
AIAA J.
,
42
(
5
), pp.
988
996
.
2.
Sunderland
,
P. B.
, and
Faeth
,
G. M.
,
1996
, “
Soot Formation in Hydrocarbon/Air Laminar Jet Diffusion Flames
,”
Department of Aerospace Engineering, The University of Michigan
,
Ann Arbor, MI
.
3.
Xu
,
F.
,
Sunderland
,
P. B.
, and
Faeth
,
G. M.
,
1997
, “
Soot Formation in Laminar Premixed Ethylene/Air Flames at Atmospheric Pressure
,”
Department of Aerospace Engineering, The University of Michigan
,
Ann Arbor, MI
.
4.
Romero
,
D.
,
Parthasarathy
,
R. N.
, and
Gollahalli
,
S. R.
,
2014
, “
Laminar Flame Characteristics of Partially Premixed Prevaporized Palm Methyl Ester and Diesel Flames
,”
ASME J. Energy Resour. Technol.
,
136
(
3
), p.
032204
.
5.
Salavati-Zadeh
,
A.
,
Esfahanian
,
V.
, and
Afshari
,
A.
,
2013
, “
Detailed Kinetic Modeling of Soot-Particle and Key-Precursor Formation in Laminar Premixed and Counterflow Diffusion Flames of Fossil Fuel Surrogates
,”
ASME J. Energy Resour. Technol.
,
135
(
3
), p.
031101
.
6.
Kochar
,
Y.
,
Seitzman
,
J.
, and
Lieuwen
,
T.
,
2011
, “
Laminar Flame Speed Measurements and Modeling of Alkane Blends at Elevated Pressures With Various Diluents
,
ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition
,
June 6–10
, ASME Paper No. GT2011-45122.
7.
Natarajan
,
J.
,
Kochar
,
Y.
,
Lieuwen
,
T.
, and
Seitzman
,
J.
,
2009
, “
Pressure and Preheat Dependence of Laminar Flame Speeds of H2/CO/CO2/O2/He Mixtures
,”
Proc. Combust. Inst.
,
32
(
1
), pp.
1261
1268
.
8.
Rozenchan
,
G.
,
Zhu
,
D. L.
,
Law
,
C. K.
, and
Tse
,
S. D.
,
2002
, “
Outward Propagation, Burning Velocities, and Chemical Effects of Methane Flames Up to 60 ATM
,”
Proc. Combust. Inst.
,
29
(
2
), pp.
1461
1469
.
9.
Vu
,
T. M.
,
Park
,
J.
,
Kwon
,
O. B.
,
Bae
,
D. S.
,
Yun
,
J. H.
, and
Keel
,
S. I.
,
2010
, “
Effects of Diluents on Cellular Instabilities in Outwardly Propagating Spherical Syngas-Air Premixed Flames
,”
Int. J. Hydrogen Energy
,
35
(
8
), pp.
3868
3880
.
10.
Dearden
,
P.
, and
Long
,
R.
,
1968
, “
Soot Formation in Ethylene and Propane Diffusion Flames
,”
J. Appl. Chem.
,
18
(
8
), pp.
243
251
.
11.
Tesner
,
P. A.
,
Robinovitch
,
H. J.
, and
Rafalkes
,
I. S.
,
1961
, “
The Formation of Dispersed Carbon in Hydrocarbon Diffusion Flames
,”
Eighth Symposium (International) on Combustion
,
Williams and Wilkins
,
Baltimore, MD
, pp.
801
806
.
12.
Chakraborty
,
B. B.
, and
Long
,
R.
,
1968
, “
The Formation of Soot and Polycyclic Aromatic Hydrocarbons in Diffusion Flames, Part Two
,”
Combust. Flame
,
12
(
3
), pp.
237
242
.
13.
McLintock
,
I. S.
,
1968
, “
The Effect of Various Diluents on Soot Production in Laminar Ethylene Diffusion Flames
,”
Combust. Flame
,
12
(
3
), pp.
217
225
.
14.
Wright
,
J. R.
,
1961
, “
Effect of Oxygen on Carbon-Forming Tendencies of Diffusion Flames
,”
Fuel
,
53
(
4
), pp.
232
235
.
15.
Berhan
,
S.
,
Chernovsky
,
M.
,
Atreya
,
A.
,
Baum
,
H. R.
, and
Sacksteder
,
K. R.
,
2003
, “
Radiant Extinction of Gaseous Diffusion Flames
,” NASA Technical Report, NASA 20040053549.
16.
Dahoe
,
A. E.
,
2005
,
Laminar Burning Velocities of Hydrogen Air Mixtures From Closed Gas Explosion
,
Faculty of Engineering, University of Ulster
,
UK
.
17.
Kuhn
,
G.
, and
Tankin
,
R. S.
,
1968
, “
Spectroscopic Measurements to Determine Temperature and Carbon Particle Size in an Absorbing Propane Diffusion Flame
,”
Spectrosc. Radiat. Transfer
,
8
(
6
), pp.
1281
1292
.
18.
Choi
,
Y. M.
,
Hamins
,
A.
,
Mulholland
,
G. W.
, and
Kashiwagi
,
T.
,
1994
, “
Simultaneous Optical Measurement of Soot Volume Fraction and Temperature in Premixed Flames
,”
Combust. Flame
,
99
(
1
), pp.
174
186
.
19.
Attia
,
A.
, and
Emara
,
A.
,
2016
, “
An Investigation of Acetylene/Argon Gas Additives to Natural Gas on the Laminar Diffusion Flame Characteristics for a Honeycomb Gaseous Burner
,”
ASME 2016 International Mechanical Engineering Congress and Exposition
,
Phoenix, AZ
,
Nov. 11–17
, ASME Paper No. IMECE 2016-66010.
20.
Attia
,
A.
, and
Emara
,
A.
,
2015
, “
An Influence of Different gas Diluents on a Laminar Coflowing Jet Diffusion Flame Temperature for a Honeycomb Gaseous Burner
,”
ASME 2015 International Mechanical Engineering Congress and Exposition
,
Houston, TX
,
Nov. 13–19
, ASME Paper No. IMECE2015-53597.
21.
Lockwood
,
F. C.
, and
Moneib
,
H. A.
,
1982
, “
Fluctuating Temperature Measurements in Turbulent Jet Diffusion Flame
,”
Combust. Flame
,
47
, pp.
291
314
.
22.
Schug
,
K. P.
,
Manheirner-Timmat
,
Y.
,
Yaccarino
,
P.
, and
Glassman
,
I.
,
1980
, “
Sooting Behavior of Gaseous Hydrocarbon Diffusion Flames and the Influence of Additives
,”
Combust. Sci. Tech.
,
22
(
5–6
), pp.
235
250
.
23.
Wolfhard
,
H. G.
, and
Parker
,
W. G.
,
1952
, “
A Spectroscopic Investigation Into the Structure of Diffusion Flame
,”
Proc. Phys. Soc.
,
65
(
1
), pp.
2
19
.
24.
Mitcho
,
D.
, and
Pal
,
A.
,
2001
,
Basic Experiments on Laser Diagnostics of Combustion
,
UNIDO
,
Vienna, Austria
.
25.
Chakraborty
,
B. B.
, and
Long
,
R.
,
1968
, “
The Formation of Soot and Polycyclic Aromatic Hydrocarbons in Diffusion Flames, III—Effect of Additions of Oxygen to Ethylene and Ethane Respectively as Fuels
,”
Combust. Flame
,
12
(
5
), pp.
469
476
.
26.
Pickett
,
L. M.
, and
Siebers
,
D. L.
,
2004
, “
Soot in Diesel Fuel Jets: Effects of Ambient Temperature, Ambient Density, and Injection Pressure
,”
Combust. Flame
,
138
(
1–2
), pp.
114
135
.
27.
Krishnan
,
S. S.
,
Lin
,
K.
, and
Faeth
,
G. M.
,
2000
, “
Optical Properties in the Visible of Overfire Soot in Large Buoyant Turbulent Diffusion Flames
,”
ASME J. Heat Transfer
,
122
(
3
), pp.
517
524
.
28.
Therssen
,
E.
,
Bouvier
,
Y.
,
Schoemaecker-Moreau
,
C.
,
Mercier
,
X.
,
Desgroux
,
P.
,
Ziskind
,
M.
, and
Focsa
,
C.
,
2007
, “
Determination of the Ratio of Soot Refractive Index Function E(m) at the Two Wavelengths 532 and 1064 nm by Laser Induced Incandescence
,”
Appl. Phys. B
,
89
(
2–3
), pp.
417
427
.
29.
Skeen
,
S.
,
Manin
,
J.
,
Dalen
,
K.
, and
Pickett
,
L. M.
,
2013
, “
Extinction-Based Imaging of Soot Processes Over a Range of Diesel Operating Conditions
,”
8th U. S. National Combustion Meeting
,
UT
,
May 19–22
, Paper No. 070IC-0355.
30.
Manin
,
J.
,
Skeen
,
S.
, and
Pickett
,
L. M.
,
2013
, “
Two-Color Diffused Back-Illumination Imaging as a Diagnostic for Time-Resolved Soot Measurements in Reacting Sprays
,”
SAE Int. J. Engines
,
6
(
4
), pp.
1908
1921
.
31.
Williams
,
T. C.
,
Shaddix
,
C. R.
,
Jensen
,
K. A.
, and
Suo-anttila
,
J. M.
,
2007
, “
Measurement of the Dimensionless Extinction Coefficient of Soot Within Laminar Diffusion Flames
,”
Int. J. Heat Mass Transf.
,
50
(
7–8
), pp.
1616
1630
.
32.
Snelling
,
D. R.
,
Liu
,
F.
,
Smallwood
,
G. J.
, and
Gulder
,
O.
,
2004
, “
Determination of the Soot Absorption Function and Thermal Accommodation Coefficient Using Low-Fluence LII in a Laminar Coflow Ethylene Diffusion Flame
,”
Combust. Flame
,
136
(
1–2
), pp.
180
190
.
33.
Fenimore
,
C. P.
, and
Jones
,
G. W.
,
1969
, “
Coagulation of Soot to Smoke in Hydrocarbon Flames
,”
Combust. Flame
,
13
(
3
), pp.
303
310
.
34.
Jagoda
,
I. J.
,
Pardo
,
G.
, and
Lahaye
,
J.
,
1980
, “
An Experimental Investigation Into Soot Formation and Distribution in Polymer Diffusion Flames
,”
Combust. Flame
,
37
, pp.
261
274
.
35.
Gay
,
N. R.
,
Agnew
,
J. T.
,
Witzell
,
O. W.
, and
Karabell
,
C. E.
,
1961
, “
Thermochemical Equilibrium in Hydrocarbon-Oxygen Reactions Involving Polyatomic Forms of Carbon
,”
Combust. Flame
,
5
, pp.
257
272
.
36.
Kelsey
,
L. K.
,
2014
, “
Effect of Hydrogen and Burner Diameters on the Stability and Structure of Lean Premixed Flames
,” M.S. thesis,
University of Iowa
,
Iowa City, IA
.
37.
Kent
,
J. H.
,
Jander
,
H.
, and
Wagner
,
H. G.
,
1981
, “
Soot Formation in a Laminar Diffusion Flame
,”
18th Symposium (International) on Combustion
, Vol.
18
. No.
1
.
Elsevier
.
38.
Kunugi
,
M.
, and
Jinno
,
H.
,
1967
, “
Determination of Size and Concentration of Soot Particles in Diffusion Flames by a Light Scattering Technique
,”
11th Symposium (International) on Combustion, the Combustion Institute
, Vol.
11
. No.
1
.
Elsevier
, pp.
257
266
.
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