Coherent Anti-Stokes Raman Scattering (CARS) for Quantitative
Temperature and Concentration Measurements in a High-Pressure Gas
Turbine Combustion Test Rig
Coherent Anti-Stokes Raman Scattering (CARS) for Quantitative
Temperature and Concentration Measurements in a High-Pressure Gas
Turbine Combustion Test Rig
Robert P. Lucht and Jay P. Gore
Purdue University, W. Lafayette, IN
Supersonics NRA Annual Review
Cleveland, OH January 27, 2010
AcknowledgmentsAcknowledgments
• Graduate students Mathew P. Thariyan (PhD), Vijaykumar Ananthanarayanan (M.S., now at Cummins), and Aizaz H. Bhuiyan (PhD), Senior Research Engineer Scott E. Meyer, Senior Research Associate Sameer V. Naik, Postdoc Dr. Ning Chai
• Technical advice from Drs. Nader Rizk, William Cummings, Mohan Razdan, Vic Oechsle, Dan Nickolaus, M. S. Anand, and Duane Smith at Rolls Royce Corporation in Indianapolis, Indiana
• Funding from NASA Glenn under Cooperative Agreement Number NNX07AC90A , technical discussions with Drs. Yolanda Hicks, Clarence Chang, and Randy Locke
MotivationMotivation
• To demonstrate dual-pump CARS measurements of CO2, N2 and temperature in the gas turbine combustor over a wide range of simulated supersonic flight conditions.
• To obtain high-quality data in the reacting flow field downstream of the NASA lean direct injection array for comparison with advanced computational models.
Outline of the Presentation Outline of the Presentation
• Optically Accessible Gas Turbine Combustor Facility
• Dual-Pump CARS Measurements: Challenges and Optical System
• Temperature Measurements: PDFs, Mean Profiles, Standard Deviation Profiles
• Conclusions and Accomplishments
• Future Work
Purdue Gas Turbine Combustion Facility (GTCF)
Purdue Gas Turbine Combustion Facility (GTCF)
High Pressure Lab
System
Maximum Flow
Capacity
Max Operating Condition
Natural Gas Heated High Pressure Air
9 lbm/sec 700 psi / 500 deg C
Electric Heated Air or Nitrogen
1 lbm/sec 600 psi / 600 deg C
Nitrogen 2 to 5 lbm/sec 1,500 psi
Liquid Aviation Fuel (Kerosene)
1 lbm/sec/tank (2 tanks)
1,500 psi
Cooling Water 40 gpm 400 psi
NASA 9-Point LDI Assembly (Top-Hat)NASA 9-Point LDI Assembly (Top-Hat)• Nine simplex injectors arranged at throats of
nine converging-diverging venturis in a 3 x 3 arrangement.
• Axial swirlers with helical vanes at 60° impart swirl to incoming heated air.
• Only central injector used for testing.
Purdue GTCF – Window Assembly Purdue GTCF – Window Assembly
Window Assembly DetailsWindow Assembly Details
3"x3" Inner Cross Section
Stagnant Air Gap
• Conventional “Single-Pump” CARS
• Noninvasive
• Coherent Laser-Like Signal
• Spatially and Temporally Resolved
• Excellent Gas Temperature Data (especially at higher temperatures)
pump
Stokes
CARS
V
pump
pump
Stokes
CARS
V
pump
Stokes
Pump1
Pump1
CARS
Coherent Anti-Stokes Raman Scattering (CARS)
Coherent Anti-Stokes Raman Scattering (CARS)
Dual-Pump CARS of N2/CO2Dual-Pump CARS of N2/CO2
Overall Experimental SystemOverall Experimental System
CARS System for GTCF MeasurementsCARS System for GTCF Measurements
SPEX
/2Pol.
Pol.
/2
/2
Pol.
S
S
S
Main Leg
Reference Leg
CL
ZL
Flow
EntranceTranslation
Stages
ExitTranslation
Stages
BD
BDBD
BDBD
BD
A: ApertureBD: Beam DumpCL: Camera LensIF: Interference FilterL: Lens/2: Half-wave-platePol: PolarizerS: ShutterTS: Translation StageZL: Zoom Lens
L5
L2 L1
L3L4
ProbeVolume
TS
TS
ProbeVolume
A
A
WindowAssembly
IF
608 nm 532 nm561 nm
496 nm
Use of Optical Parametric Oscillator/ Pulsed Dye Amplifier System
Use of Optical Parametric Oscillator/ Pulsed Dye Amplifier System
355 nm
OPO
560 nm
607 nm
532 nm
See
ded
Nd
:YA
G
BS
970 nm
BSBS
0 Mirror
0 Mirror
To Purdue GTCF
Optical Arrangement for Laser Beam Generation
Optical Arrangement for Laser Beam Generation
Dual-pump CARS SystemDual-pump CARS System
Measurement Challenges in GTCFMeasurement Challenges in GTCF
• Translation of probe volume inside the flame zone.
• Installation of pin-hole for spatial overlap of CARS beams not possible, must use referemce leg alignment.
• Measurement of non-resonant signal in the reference leg for spectral normalization of CARS signal.
• Safety of thin window, CARS beams are focused tightly in the middle of the test section.
CARS Probe Volume TranslationCARS Probe Volume Translation
/2
/2Pol.
Pol.
/2
Pol.
S
S
S
Main Leg
Reference Leg
CL
ZL
Flow
Entrance Translation
Stages
Exit Translation
Stages
BD
BDBD
BDBD
BD
A: ApertureBD: Beam DumpCL: Camera LensIF: Interference FilterL: Lens/2: Half-wave-platePol: PolarizerS: ShutterTS: Translation StageZL: Zoom Lens
L5
L2 L1
L3L4
ProbeVolume
TS
TS
ProbeVolume
A
A
WindowAssembly
IF
608 nm 532 nm561 nm
496 nm
Optical System near GTCFOptical System near GTCF
CARS System Reference LegCARS System Reference Leg
CARS System Reference LegCARS System Reference Leg
SPEX
/2Pol.
Pol.
/2
/2
Pol.
S
S
S
Main Leg
Reference Leg
CL
ZL
Flow
EntranceTranslation
Stages
ExitTranslation
Stages
BD
BDBD
BDBD
BD
A: ApertureBD: Beam DumpCL: Camera LensIF: Interference FilterL: Lens/2: Half-wave-platePol: PolarizerS: ShutterTS: Translation StageZL: Zoom Lens
L5
L2 L1
L3L4
ProbeVolume
TS
TS
ProbeVolume
A
A
WindowAssembly
IF
608 nm 532 nm561 nm
496 nm
Probe Volume TranslationProbe Volume Translation
DP-CARS Detection OpticsDP-CARS Detection Optics
Raman Shift (cm-1)
1300 1320 1340 1360 1380 1400
(CA
RS
Int
ensi
ty)1/
2 (
arb.
uni
ts)
-15
-5
5
15
25
35
45
55
65
75
DataTheoryResidual
T = 1325 KCO2/N2 = 0.079 N2
CO2
N2
Comb. Pr. = 100 psia., Eq. Ratio = 0.8
Operating Conditions, Measurement Locations and Sample DP-CARS Spectra
Operating Conditions, Measurement Locations and Sample DP-CARS Spectra
Φ=0.4 Φ=0.59 Φ=0.80 Φ=1.0
100 psia(7.0 atm.)
■ ■ ■ ■
125 psia(8.5 atm.)
■
150 psia(10 atm.)
■
+ 3 mm
+ 6 mm
+ 9 mm+ 11 mm
- 3 mm
- 6 mm
- 9 mm- 11 mm
F = 0.6P = 100 psiDP/P = 4%
10 mm
Note: Distance between points along the centerline is 5 mm
• Burner Inlet Temperature: 850 0F (725 K)• Fuel: Jet-A • Normalized injector pressure drop = 4%
Purdue GTCF in Operation Purdue GTCF in Operation
F= 0.45, Pcomb= 120 psia, Tinlet = 780° F
Central injector operation
Flame Characteristics @ 100 psiaFlame Characteristics @ 100 psia
Φ =0.8 Φ =1.0
Φ =0.4 Φ =0.59
Data AnalysisData Analysis
1000 to 2000 spectra collected at each measurement location.
Spectra with low average N2 signal counts and droplet
interferences rejected.
Square-root of background corrected normalized CARS spectra analyzed using Sandia CARSFT code in the batch processing mode.
N2 spectra analyzed for optimal temperature, horizontal
and vertical shift, instrument function etc.
Spectra with low peak CO2 counts rejected. CO2 part of
the spectrum analyzed for CO2/N2 concentration ratio.
Data ProcessingData Processing
Raw ImageAveraged Stokes BlockedBackground Corrected ImageCorrected Non-Resonant SignalFinal Corrected Image
Temp PDFs Along CenterlineTemp PDFs Along Centerline
Temperature PDF: Z = 15 mm, R = 0 mm
Cou
nts
Temperature (K)
1000 1250 1500 1750 2000 2250 2500 27500
20
40
60
80
100
120
140
160
Mean Temp. = 1820 KStd. Dev. = 340 K
(b)
Temperature PDF: Z = 10 mm, R = 0 mm
Cou
nts
Temperature (K)
1000 1500 2000 2500 30000
20
40
60
80
100
Mean Temp. = 2020 KStd. Dev. = 370 K
(a)
Combustor Pressure: 104 psia, Equivalence Ratio: 0.4
Temperature PDF: Z = 25 mm, R = 0 mm
Cou
nts
Temperature (K)
1000 1200 1400 1600 1800 2000 2200 24000
20
40
60
80Mean Temp. = 1595 K
Std. Dev. = 267 K(a)
Temperature PDF: Z= 50 mm, R= 0 mm
Cou
nts
Temperature (K)
1000 1200 1400 1600 1800 20000
20
40
60
80
100
Mean Temp. = 1340 KStd. Dev. = 180 K
Temp PDFs at Different LocationsTemp PDFs at Different LocationsCombustor Pressure: 104 psia., Equivalence Ratio: 0.4
Temperature PDF: Z = 10 mm, R = 6 mmC
ount
s
Temperature (K)
1000 1250 1500 1750 2000 2250 2500 27500
20
40
60
80
100
120
140
Mean Temp. = 1835 KStd. Dev. = 340 K
(b)
Temperature PDF: Z = 10 mm, R = 9 mm
Cou
nts
Temperature (K)
1000 1500 2000 2500 30000
20
40
60
80
100
120Mean Temp. = 1760 K
Std. Dev. = 410 K(c)
Temperature PDF: Z = 20 mm, R = 6 mm
Cou
nts
Temperature (K)
1000 1200 1400 1600 1800 20000
20
40
60
80Mean Temp. = 1520 K
Std. Dev. = 235 K(e)
Temperature PDF: Z = 20 mm, R = 9 mm
Cou
nts
Temperature (K)
800 1000 1200 1400 1600 1800 2000 22000
20
40
60
80Mean Temp. = 1405 K
Std. Dev. = 265 K(f)
Mean Temperature &
Temperature Standard Deviation Profiles
Mean Temperature &
Temperature Standard Deviation Profiles
Combustor Pressure: 104
psia
Equivalence Ratio: 0.4
Radial Distance (mm)
0 2 4 6 8 10 12
Tem
pera
ture
(K
)
1200
1400
1600
1800
2000
2200
Z = 10 mmZ = 20 mmZ = 45 mm
(a)
Radial Distance (mm)
0 2 4 6 8 10 12
Rel
ativ
e T
emp.
Std
. D
ev.
(%)
10
15
20
25
30
35
40Z =10 mmZ = 20 mmZ = 45 mm
(b)
Mean Temperature ProfilesMean Temperature Profiles
1300
1400
1500
1600
1700
1800
1900
2000
2100
10 15 20 25 30 35 40 45 50
F = 0.4
150 psia100 psia
Mea
n T
empe
artu
re (
K)
Axial Distance (mm)
1200
1400
1600
1800
2000
2200
10 15 20 25 30 35 40 45 50
100 psia
F = 0.8F= 0.4
Mea
n T
empe
artu
re (
K)
Axial Distance (mm)
Mean Temperature ProfilesMean Temperature Profiles
1200
1300
1400
1500
1600
1700
1800
-12 -8 -4 0 4 8 12
Z = 20 mm, 150 psia, F = 0.4
Mea
n T
empe
artu
re (
K)
Vertical Distance (mm)
Temperature and CO2/N2 PDFsTemperature and CO2/N2 PDFs
Temperature PDF: Z = 25 mm, R = 0 mmC
ount
s
Temperature (K)
1000 1200 1400 1600 1800 2000 2200 24000
20
40
60
80Mean Temp. = 1595 K
Std. Dev. = 267 K(a)
CO2/N2 Conc. Ratio PDF: Z = 25 mm, R = 0 mm
Cou
nts
CO2/N2 Concentration Ratio
0.02 0.04 0.06 0.08 0.10 0.12 0.140
10
20
30
40
50Mean CO2/N2 = 0.0625
Std. Dev. = 0.0212(c)
Temperature PDF: Z = 30 mm, R = 3 mm
Cou
nts
Temperature (K)
1000 1200 1400 1600 1800 2000 22000
20
40
60
80
100
(b) Mean Temp. = 1515 KStd. Dev. = 205 K
Combustor Pressure: 104 psia., Equivalence Ratio: 0.4
CO2/N2 Concentration Ratio
0.00 0.02 0.04 0.06 0.08 0.10 0.12
Cou
nts
0
10
20
30
40
Mean CO2/N2 = 0.0546
Std. Dev. = 0.019(d)
CO2/N2 Conc. Ratio PDF: Z = 30 mm, R = 3 mm
Temperature and CO2/N2 Scatter Temperature and CO2/N2 Scatter Combustor Pressure: 104 psia., Equivalence Ratio: 0.4
Temp. vs CO2/N2 Correlation: Z = 25 mm, R = 0 mm
Temperature (K)
1000 1200 1400 1600 1800
CO
2/N
2 C
once
ntra
tion
Rat
io
0.00
0.02
0.04
0.06
0.08
0.10
0.12
1000 1200 1400 1600 18000.00
0.02
0.04
0.06
0.08
0.10
0.12
Temp. vs CO2/N2 Correlation: Z = 30 mm, R = 3 mm
CO
2/N
2 C
once
ntra
tion
Rat
io
Temperature (K)
Accomplishments and ConclusionsAccomplishments and Conclusions
GTCF has been operated at wide range of simulated supersonic flight conditions. The optically accessible GTCF has been operated up at pressures up to150 psia, single-shot dual-pump CARS measurements obtained at all operating conditions.
Approximately 500,000 single-shot spectra were acquired in a test campaign conducted during the summer of 2009. These spectra are being processed to obtain temperature and CO2/N2 concentration ratio
values at various equivalence ratios at multiple axial and vertical positions downstream of the LDI injector.
Accomplishments and ConclusionsAccomplishments and Conclusions
A new OPO/PDA system was used to generate the 560-nm pump beam in the dual-pump CARS system. Considerable care in allignment was required for all beams to obtain good beam quality in the combustor test cell.
The Zaber translation stages performed well, alignment was maintained over the entire spatial region of interest during the test.
The reference leg was invaluable for alignment and for frequent recording of the nonresonant signal. Alignment was maintained before and after translation of the large 2-inch prisms.
Accomplishments and ConclusionsAccomplishments and Conclusions
Data analysis is still in progress. Filtering techniques to remove spectra with signals that were too low have been developed and are still being optimized. .
Experimental results will be compared with computational results obtained from, for example, the National Combustion Code (NCC). The data will be provided in a form decided in collaboration with NASA personnel.
Accomplishments and ConclusionsAccomplishments and Conclusions
Estimated uncertainty in temperature measurements : Accuracy: 1-2% Precision: 2-3%
Uncertainty in CO2/N2 ratio measurements : Very dependent on CO2 concentration and on the
temperature, approximately 10% relative standard deviation in the range of 5% CO2 concentation around 1500 K.
Probe volume dimensions: 500 μm along the laser propagation direction. 50 μm perpendicular to the laser direction.
Papers and PresentationsPapers and Presentations
1. Mathew P. Thariyan, Aizaz H. Bhuiyan, Sameer V. Naik, Jay P. Gore, and Robert P. Lucht, “Temperature and CO2 Concentration Measurements in a High-Pressure, Lean Direct Injector Combustor using Dual-Pump CARS,” paper submitted to the 33rd Combustion Symposium.
2. Mathew P. Thariyan, Aizaz H. Bhuiyan, Scott E. Meyer, Sameer V. Naik, Jay P. Gore, and Robert P. Lucht, “Optically Accessible, High-Pressure Gas Turbine Combustion Facility and Dual-Pump CARS System,” paper in preparation for submission to Measurement Science and Technology.
Papers and PresentationsPapers and Presentations
3. M. P. Thariyan, V. Ananthanarayanan, A. H. Bhuiyan, S. E. Meyer, S. V. Naik, J. P. Gore and R. P. Lucht, “Dual-Pump CARS Temperature and Major Species Concentration Measurements in Laminar Counterflow Flames and in a Gas Turbine Combustor Facility,” Paper AIAA-2009-1442, presented at the 47th Aerospace Sciences Meeting, Orlando, Florida, January 5-8, 2009.
4. M. P. Thariyan, A. H. Bhuiyan, N. Chai., S. V. Naik, R. P. Lucht, and J. P. Gore, “Dual-Pump CARS Temperature and Major Species Concentration Measurements in a Gas Turbine Combustor Facility,” Paper AIAA 2009-5052, 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Denver, Colorado, 2-5 August 2009.
5. M. P. Thariyan, A. H. Bhuiyan, N. Chai, S. V. Naik, R. P. Lucht, and J. P. Gore, “Dual-Pump CARS Measurements in a Gas Turbine Combustor Facility Using the NASA 9-point LDI Injector,” Paper AIAA-2010-1401, presented at the 48th Aerospace Sciences Meeting, Orlando, Florida, January 4-7, 2010.
Typical Dual-Pump CARS spectraTypical Dual-Pump CARS spectra
Pressure: 100 psia. @ F = 1.0, 40 mm Center-line
Modified Combustor Window Assembly (CWA) for RRC Injector
Modified Combustor Window Assembly (CWA) for RRC Injector
Cross section increased from 3"x3“ to 4.2"x4.2". The modified CWA is fabricated from Hastelloy-X instead of stainless steel. Brazing has been eliminated. Film cooling air passages are incorporated in the injector assembly rather than in the CWA. Thermal barrier coatings are being applied to the window assembly inner surfaces.
Upstream spool section has been redesigned to accommodate the larger injectors and to ensure uniform flow into the injector.
Downstream spool sections redesigned for larger flow cross section.
Modified Combustor Window Assembly (CWA) for RRC Injector
Modified Combustor Window Assembly (CWA) for RRC Injector
Modified Combustor Window Assembly (CWA) for RRC Injector
Modified Combustor Window Assembly (CWA) for RRC Injector