ECN 3: Flame structure 1/19April 2014
Experimental analysis between Experimental analysis between LIF-OH/355 from IFPEN, SANDIA and TU/eLIF-OH/355 from IFPEN, SANDIA and TU/e
H. Baya Toda, M. Meijer, N. Maes, S. Skeen, L. Pickett, LM, Malbec, G. Bruneaux
Third Workshop of the Engine Combustion Network,
April 4-5, 2014, Ann Arbor, USA,
ECN 3: Flame structure 2/19April 2014
• Analyze the spray flame structure
• Assess the repeatability of measurements among different institutions
• Improve measurements/post-processing for more reliable results for next ECN meetings
Objectives
ECN 3: Flame structure 3/19April 2014
• Flame phases – spray A
• Operating conditions for comparisons
• Hardware comparisons
• 2D and 1D profiles comparisons
Contents
ECN 3: Flame structure 4/19April 2014
0 1000 2000 3000 4000 5000 6000 7000time [us]
0
10
20
30
40
50
60
70
80
90
100
110s[
mm
]
BBand(soot)
ShadowR
ShadowI
LOL-OH*
LOL(t)-BBand
Analysis of flame phases – Spray A
sR sinert
FTP
SOC
I II IIIEOI
LOL OH*
FL
Sources of information – Shadowgraphy (CMT)– OH* Chemiluminescence LOL OH* (CMT) – Broadband chemiluminescence
• FTP(t) = Flame Tip Penetration (CMT)• LOL(t) (Sandia)
LOL(t)
ECN 3: Flame structure 5/19April 2014
0 1000 2000 3000 4000 5000 6000 7000time [us]
0
10
20
30
40
50
60
70
80
90
100
110s[
mm
]
BBand(soot)
ShadowR
ShadowI
LOL-OH*
LOL(t)-BBand
Analysis of flame phases – Spray A
sR sinert
FTP
SOC
I II IIIEOI
LOL OH*
FL
LOL(t)
Combustion stages – (I) = Autoignition and early development
• From SOC until reacting penetration accelerates over inert case• The reacting spray undergoes a transition from inert to reacting flow
ECN 3: Flame structure 6/19April 2014
0 1000 2000 3000 4000 5000 6000 7000time [us]
0
10
20
30
40
50
60
70
80
90
100
110s[
mm
]
BBand(soot)
ShadowR
ShadowI
LOL-OH*
LOL(t)-BBand
Analysis of flame phases – Spray A
sR sinert
FTP
SOC
I II IIIEOI
LOL OH*
FL
LOL(t)
Combustion stages – (II) = Mature flame
• From the end of (I) until EOI• (IIA) Transient mature flame – LOL still unsteady (upto 2000 us)• (IIB) Quasi-steady mature flame – LOL steady but FTP increasing (upto 4000 us)• (IIC) Steady flame – FTP steady (FL)
ECN 3: Flame structure 7/19April 2014
0 1000 2000 3000 4000 5000 6000 7000time [us]
0
10
20
30
40
50
60
70
80
90
100
110s[
mm
]
BBand(soot)
ShadowR
ShadowI
LOL-OH*
LOL(t)-BBand
Analysis of flame phases – Spray A
sR sinert
FTP
SOC
I II IIIEOI
LOL OH*
FL
LOL(t)
Combustion stages – (III) = Burn-out phase
• From EOI onwards
ECN 3: Flame structure 8/19April 2014
Operating conditions for comparisons
Phases IFPEN SANDIA TU/e
PLIF-355 Transient 0.7 ms 0.7 ms X
Stabilized 2.7 ms 2.5 ms 4.7 ms*
PLIF-OH Transient 0.7 ms X 0.7 ms*
Stabilized 4.7 ms X 4.7 ms** Assuming an identical hydraulic delay as at IFPEN: 300us
0 1000 2000 3000 4000 5000 6000 7000time [us]
0
10
20
30
40
50
60
70
80
90
100
110
s[m
m]
BBand(soot)
ShadowR
ShadowI
LOL-OH*
LOL(t)-BBand
sR sinert
FTP
SOC
I II IIIEOI
LOL OH*
FL
LOL(t)
ECN 3: Flame structure 9/19April 2014
Hardware differences
IFPEN SANDIA TU/e
Injectors 201-02 370 201-01
PLIF-355 Laser sheet 55 mm 65 mm 90 mm
Energy 100 mJ 100 mJ 110 mJ
PLIF-OH Excitation line Q1(6) 282.920 Q1(9) 283.928
Energy 11-17 mJ 11 mJ
Laser sheet 40 mm* 30 mm
* Measurements were performed with two laser sheets
ECN 3: Flame structure 10/19April 2014
Flame structure – Spray A
Liquid phase
Formaldehyde
Hot burnt gases
PAH
Reaction zone
1. The formaldehyde structure decreases when increasing tempereature/ [O2]
2. The PLIF-OH signal start « almost » at LOL (OH*)
ECN 3: Flame structure 11/19April 2014
PLIF-355: 2D comparisons
Formaldehyde
PAH
ECN 3: Flame structure 12/19April 2014
PLIF-355: 2D comparisons IFPENSANDIA
ECN 3: Flame structure 13/19April 2014
PLIF-355: 2D comparisons
Formaldehyde
ECN 3: Flame structure 14/19April 2014
PLIF-OH: 2D comparisons t = 4.7 ms ASOI
ECN 3: Flame structure 15/19April 2014
Profiles comparison: PLIF-OH
ECN 3: Flame structure 16/19April 2014
PLIF-OH: 2D comparisons t = 0.7 ms ASOI
Not the same structure ?
•Laser profile correction ?
•Timing ?
•AI delay differences ?
Not the same penetration
•Ambient conditions ?
•Injector to injector variations ?
•Hydraulic delay ?
ECN 3: Flame structure 17/19April 2014
PLIF-OH: 2D comparisons t = 0.7 ms ASOI
0.4 ms 0.7 ms
4.7 ms 0.7 - 1 ms
ECN 3: Flame structure 18/19April 2014
Conclusions
• Good agreement for PLIF-355 measurments • Transient (IFPEN and SANDIA)• Steady phase (IFPEN,TU/e and SANDIA)
• Good agreement for PLIF-OH measurements at steady state phase
• PLIF-OH comparisons during transient phases are more difficult and need more time for investigation
• PLIF-OH from TU/e more suitable for LOL estimation because of the stable energy laser
ECN 3: Flame structure 19/19April 2014
Thank you to all the contributors and good luck to the CFD GUYS !