a triple-flame, n+3 generation mixer - university of...
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A Triple-Flame, n+3 Generation Mixer
Hukam Mongia, Purdue UniversityAli Mahallati and Wajid Chishty, NRC-Institute for Aerospace Research
Presented at
The 2nd UTIAS-MITACS International Workshop on Aviation and Climate ChangeUniversity of Toronto Institute for Aerospace Studies in Toronto, Ontario, Canada, May 27-28, 2010.
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Outline of Presentation
Motivation– Lower emissions and alternative fuelsSingle annular combustors – Pre- and Low-emissions Combustors, LECDual-annular combustors for the CFM56 and GE90 enginesTwin-Annular Premixing Swirl (TAPS) technology for the CFM56 and GE90 size enginesEmissions comparisonTriple-Flame Mixer
Description and Analytical Design StatusPreliminary data from NRCC
Future Plan
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Motivation for the proposed work comes from:2009 Copenhagen UN Framework Convention on Climate Change, UNFCC)-Aviation industry agreed:
Improve fuel efficiency of the world aircraft fleet by 1.5% per yearCap aviation CO2 footprint at 2020 level50% of the 2005 CO2 level by 2050.
The challenges described well by:Ted Thrasher, ICAO’s Activities on International Aviation and Climate ChangeJohn Green, Climate change, fuel burn targets and the options and limitations facing the designer Scott Hartman, Alternative Fuels in Air Transport — From Lab to World Scale Plant Fayette Collier, Overview of the Environmentally Responsible Aviation Project Dan Bulzan, NASA Emissions Reduction and Alternative Fuel ResearchChi-Ming Lee, Technical Challenges of Low Emissions and Fuel Flexible Combustors .
Let me therefore focus on developing aviation combustion technology for:Further reducing NOx emissions for future energy efficient enginesCombustibility and increased operability with conventional & alternative fuels.
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COCO
NO NOLow-Power High-Power
NO/CO/Operability Tradeoffs in a typical rich-dome combustor
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CFM56 Combustion Technologies and Products
Single Annular CombustorsPre-LEC & Low-Emissions Comb
Dual Annular CombustorsDAC I, DAC II and DAC II+
GE 90 Combustion Technologies and Products
DAC I, DAC II and DAC II+
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Twin-Annular Premixing Swirl (TAPS) stabilized Flames technology developed for potential applications in the CFM56 and GE90 engine models.Typical values quoted.
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NASA GRC and GE Aviation supported the development of the CFM and GE90 TAPS technologies
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0
5
10
15
20
22 27 32 37
LTO
HC
Takeoff PR
CFM56_95
CFM56_96
CFM56_97
CFM56_TAPS
CFM56_05
20
40
60
80
100
120
140
22 24 26 28 30 32 34
LTO
CO
Takeoff PR
CFM56_95
CFM56_96
CFM56_97
CFM56_TAPS
CFM56_05
0
5
10
15
20
22 27 32 37
Ch
. Sm
oke
Takeoff PR
CFM56_95
CFM56_96
CFM56_97
CFM56_TAPS
CFM56_05
75%Reduction
75%Reduction
20
30
40
50
60
70
80
22 27 32 37
LTO
NO
x
Takeoff PR
CFM56_95
CFM56_96
CFM56_97
CFM56_TAPS
CFM56_05
CFM56_PLEC
39% reduction
49%
8
Further reduction in TAPS CO emissions would be desirable for low pressure ratio engines
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01
2
34
5
678
9
34 36 38 40 42 44
LTO
HC
Takeoff PR0
10
20
30
40
50
60
70
34 36 38 40 42 44
LTO
CO
Takeoff PR
20
30
40
50
60
70
80
90
34 36 38 40 42 44
LTO
NO
x
Takeoff PR
GE90_95
GE90_97
GE90_03
GE90_TAPS-FAR
0
2
4
6
8
10
12
34 36 38 40 42 44C
h. S
mo
ke
Takeoff PR
GE90_95
GE90_97
GE90_03
GE90_TAPS-FAR
75%
45%Reduction
85%Reduction
9
GE90 TAPS technology demonstrated significant emissions reduction compared to current technology GE90 combustion system
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(a)
(d)(c)
(b)(e)
(f)
Instantaneous Vorticity contours
Time-averaged
Time-averaged CH2O PLIF
Pilot (P) fueled
P+M fueled
Twin-Flames TAPS Mixer
Pilot
Main
PRZ
CRZ
LRZ
PRZ
Typical TAPS diagnostics data from Prof. Driscoll and his studentsShow twin flames as hypothesized for TAPS mixers
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10
15
20
25
30
35
40
22 27 32 37
NO
xEI
Takeoff PR
CFM56_95
CFM56_96
CFM56_97
CFM56_TAPS
CFM56_05
CFM56_PLEC
TFM-Goal
5
15
25
35
45
55
65
34 36 38 40 42 44
NO
xEI
Takeoff PR
GE90_95
GE90_97
GE90_03
GE90_TAPS
TFM-30PR
TFM-40
TFM GoalsReduce NOxEI by ~50%*Simplify fuel injectors*Reduce hot-streakingImprove operabilityIncrease fuel flexibility
*Baseline combustors areCFM56 TAPS and GE90 TAPS
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Triple-Flame Mixer“Optimized strain/vorticity /FAR distribution
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Triple-Flame Mixer with optimized strain, vorticity and distribution
Vorticity Magnitude
Axial velocity
RANS Non-reacting flow; DES/LES simulation continues
CW3%
45o-vane angles
CW30%
CW10%
CW7%
CC15%
CC20%
Direct Fuel Injection, DFI, No premixing or liquid fuel jets in cross-flow.
DFI1 & DFI2 fuel flow continuously
aa5aa4
aa3aa2
aa1
aa1, aa2 ----and aa5 are the potential air atomizing locations
1
2
3
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Takeoff: 45.7 atm, 918K, 0.0279 fuel/air ratio
0< <15000 s-1
0< <1.6
-80<u<120 m/s
Progress Variable
700<T<2600K
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0< <15000 s-1
0< <1.6
-80<u<120 m/s
Progress Variable
700<T<2600K
Cruise: 21.4 atm, 737K, 0.0287 fuel/air ratio
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u<0
Preliminary Data and current status on 2-D RANS axial velocity normalized contours
Work in progress on data and simulations including LES/DES
Axial Velocity Contours Data
P0i, Psi
Ui
iU/u
Reversed Flow
Reverse-flow
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Preliminary Data and current status on 2-D RANS Total pressure coefficient contours
Total Pressure Coefficient Contours Data
sii0
si00
PP
PPCp
P0i, Psi
Ui
Reversed Flow
Reverse-flow
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Preliminary Data and current status on 2-D RANS Static pressure coefficient contours
Static Pressure Coefficient Contours Datasii0
siss
PP
PPCp
P0i, Psi
Ui
Reversed Flow
Reverse-flow
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Axial Velocity Data 3mm downstream of mixer exit
Reversed Flow
iU/u Total Pressure Coefficient Data 3 mm downstream of mixer exit
Reversed Flow
sii0
si00
PP
PPCp
Static Pressure Coefficient Data 3 mm downstream of mixer exit
Reversed Flow
sii0
siss
PP
PPCp
Axial Vorticity Data 3 mm downstream of mixer exit
∂
∂-
r
)∂( rx
uru
r
1
Reversed Flow
r
Excellent quality data for modeling and simulation
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Axial Velocity Data 3 mm downstream of mixer exit
Reversed Flow
Design Flow Rate
Twice Design
Flow Rate
iU/u
Axisymmetric quality of axial velocity contours improves with increased airflow rate.
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Total Pressure Coefficient Data 3 mm downstream of mixer exit
Reversed Flow
Design Flow Rate
Twice Design
Flow Rate
sii0
si00
PP
PPCp
Axisymmetric quality of total pressure coefficient contours improves with increased airflow rate.
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Future Plan for Triple-Flame Mixer
1. Continue design optimization for cold and reacting flows
2. Design, fabrication and preliminary testing at engine relevant conditions
in collaboration with a fuel nozzle vendor and NRCC
3. Conduct comprehensive diagnostics at engine relevant conditions with
“10 kHz” PIV/PLIF, kHz Dual-Beam CARS, Spray patternation (SETScan
optical patternator) and X-Ray tomography (dense sprays)
4. Design, fabricate and test “5 lb/sec” TFM in a flame tube rig at inlet
pressure and temperature approaching 25 bar and 600oC followed by
testing on a three nozzle sector
5. Formulate and validate engineering correlations, 3-D modeling and
simulation approach for combustion technology and design community.
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