high pressure single pulse shock tube (hpst) experimentscombust/muri/papers/brezinsky... · 2007....
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High Pressure Single Pulse Shock Tube (HPST) Experiments
Kenneth BrezinskyMechanical Engineering
University of Illinois, Chicago
2007 AFOSR MURI Kick-Off MeetingGeneration of Comprehensive Surrogate Kinetic Models andValidation Databases for Simulating Large Molecular Weight
Hydrocarbon Fuels
Holiday Inn, Princeton100 Independence Way
Princeton, NJ 08540
September 17, 2007
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Background
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Single Pulse Shock TubeDriver DrivenDiaphragm
Dump Tank
Shock tube sections heated to 100o C preventing loss of large condensable species
Eight pressure transducer ports lie along the sidewall to determine shock velocity
One on the end port to determine ignition delay
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Heating the Shock Tube
Water present100 +/- 2 °C over last 30 inches of tubeOmega Controllers
2 controllers for tube
700 720 740 7601200
1300
1400
1500 Ideal Calibrated
100 atm Calibration
T5 (K
)
Extrapolated Shock Velocity (m/s)
0 5 10 15 20 25 30 35
80
90
100
110
120
Temperature Distribution
Tem
pera
ture
(C)
Distance from end wall (in)
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GC and GC/MS
Two Hewlett-Packard 6890 series Gas Chromatographs and a Hewlett-Packard 5973 series Mass Spectrometer
Detectors - PDD, TCD, FID
Mass Spectrometer
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Chemical Thermometers
Treal = (-E/R)/ln{[-ln(1-x)]/At}
x = {[CF3 CH3 ]0 - [CF3 CH3 ]f }/ [CF3 CH3 ]0
From loss of parent molecule:
CF3 CH3 → CF2 CH2 + HFC6 H10 → C4 H6 + C2 H4
Two ‘thermometers’
1150 K - 1350 K1050 K - 1150 KEa/R = 33.4 K Ea/R = 39.0 K
Note: Calibration performed for every pressure range
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Reaction Time
0.0000 0.0006 0.0012 0.0018 0.0024
0
2000
4000
6000
8000
10000t=1.43 ms
Pmax
80% of Pmax
P5=600 barT5-avg.=1300 Kτ=1.43 msP
ress
ure
/psi
Time /s
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Toluene Oxidation Species Profiles
Stable species
Radicalspecies
Quenchingperiod
Reactingperiod
0.0000 0.0005 0.0010 0.0015 0.0020 0.00250
5
10
15
20
25
(a) C6H5CH3
T5-avg.=1300 K
Symbols: Constant T5, P5Lines: With T5, P5 correction
Time /sM
ole
frac
tion
/ppm
τ=1.43 ms
0.0000 0.0005 0.0010 0.0015 0.0020 0.00250.000
0.005
0.010
0.015
0.020
0.025
0.030
Time /s
Mol
e fr
actio
n /p
pm
OH(c)
Symbols: Constant T5, P5Lines: With T5, P5 correction
T5-avg.=1300 Kτ=1.43 ms
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Well Characterized Shock Tube for Chemical Kinetic Studies under Non-ideal Conditions
From W. Tang, K. Brezinsky, Int. J. Chem. Kin., 38, 2006, 75-97
Constant T and P approximations:Acceptable with a
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A. Lifshitz, "Ignition Delay Times", in Handbook of Shock Waves,
Volume 3, Pages 212-256, Eds. Gabi Ben-Dor, Ozer Igra and Tov Elperin, Academic Press, 2001.
Ignition Delay
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Examples
Benzene PyrolysisPressure range from 30 - 50 barsTemperature range of 1200 - 1800 KReaction times from 1.2 - 1.5 ms.Two reagent mixtures, 84 and 800 ppm
Toluene Pyrolysis and OxidationPressure range from 25 - 610 barsTemperature range from 1200 - 1500 KMixtures with 8 - 85 ppm of Toluene
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Benzene PyrolysisC6H6 - 25 atm, 65ppm
010203040506070
1200 1400 1600 1800 2000
Temperature/T5 K
PPM
Experimental
Final
Laskin-Lifshitz
Wang
Proc.2004+BenzUpdate
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1200 1400 1600 18000
1
20
102030
Mol
e Fr
actio
n/ p
pm
T/ K
050
100150
Toluene Pyrolysis -
ExperimentalP ~ 27 and 45 bars, T ~ 1100-1900 K
[C6
H5
CH3
]i
~ (1-5)x10-8
mol/cc
[●] –
C6
H5
CH3
, [▲] –
C2
H2
, [□] -
C6
H6
, [◊] –
CH4
, [X] –
C4
H2
, [+] –
C8
H10
, [ο] –
C8
H6
, [Δ] –
C9
H8
27 bars
1200 1400 1600 18000
1
20
102030
Mol
e Fr
actio
n/ p
pm
T/ K
050
100150
45 bars
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Toluene Oxidation : 600 bar, Φ=1Mixture 1
[C6
H5
CH3
]o = 8ppm
1240 1280 1320 1360 1400
0
2
4
6
8
10
12
14
16
Con
cent
ratio
n /p
pm
Temperature /KC6
H5
CH3 C6
H6 CO CO2Species Observed in Trace Amounts : 1,3-C4
H6
and C2
H4
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Experimental KBG
KBG Model Comparison to High Pressure Data
(a) : Klotz, S.D., Brezinsky, K., Glassman, I., Proc. Symp. Int.
Comb., 27, 1998, 337.
Ф=1, 610 bar, [C6
H5
CH3
]o
=12 ppm
1250 1300 1350 1400 1450 15002
4
6
8
10
12
14
[C6H
5CH
3] /p
pm
T5 /K
Ф=5, 610 bar, [C6
H5
CH3
]o
=14 ppm
KBG Model a
: 98 species, 529 reactions.Model validated : P=1atm and T
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Sensitivity Analysis
Normalized Sensitivity Coefficient
Φ=1 Φ=5
Sensitivity Spectrum [C6
H5
CH3
]P=600 bar, T=1350 K, t=1.4 ms
-0.3 -0.25 -0.2 -0.15 -0.1 -0.05 0 0.05 0.1
1
Rxn # Reactions in KBG Model
2. O+OH=H+H2
0
4. H+O2 (+M)=HO2
(+M)
458. C6
H5
+O2
=C6
H5
O+O
484. C6
H5
CH2
+H=C6
H5
CH3
486. C6
H5
CH3
+O2
=C6
H5
CH2
+HO2
492. C6
H5
+C6
H5
CH3
=C6
H6
+C6
H5
CH2
495. C6
H5
CH2
+O=C6
H5
CHO+H
C6
H5
+CH2
O+OHC6
H5
CHO+H+OHC6
H5
CH2
+HO2498.497.498
495
492
486
484458
4
2
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Model Modifications
1. Glarborg et al., Int. J. Chem. Kin., 2000. 2. Just et al., Proc. Symp. Int. Comb., 1994. 3. Colket et al.,Proc. Symp. Int. Comb., 1994. 4. Baulch et al., J. Phys. Chem., 1992. 5. Scherer et al., Proc. Symp. Int.Comb., 2000. 6. Colussi et al., J. Phys. Chem., 1988. 7. Miller et al., Combustion and Flame., 1992.a. Klotz et al., Proc. Symp. Int. Comb., 27, 1998, 337.
b. Baulch et al., J. Phys. Chem. Ref. Data., 1994.
3971701.81E+12C6H5CH3+O2=C6H5CH2+HO2486b4140003.00E+14C6H5CH3+O2=C6H5CH2+HO2486a
81702.87E+14C4H3+C2H3=C6H65366
14002.92.80E+03C4H3+C2H2=C6H55377
7100003.00E+15C5H5=C2H2+C3H35383, adj
00 7.50E+12C3H3+C3H3=C6H6535510743009.00E+15C6H6=C4H4+C2H253447000002.00E+14C6H5CH2=C2H2+C5H55333, adj8360002.00E+14C6H5CH2=C4H4+C3H35323898203.00E+13C6H5+O2=p-C6H4O2+H5312
008.50E+13C6H5O+O=p-C6H4O2+H5301
cal (mol K) -1cc (mol s)-
1
E bA ReactionReaction Number
3971701.81E+12C6H5CH3+O2=C6H5CH2+HO2486b4140003.00E+14C6H5CH3+O2=C6H5CH2+HO2486a
81702.87E+14C4H3+C2H3=C6H65366
14002.92.80E+03C4H3+C2H2=C6H55377
7100003.00E+15C5H5=C2H2+C3H35383, adj
00 7.50E+12C3H3+C3H3=C6H6535510743009.00E+15C6H6=C4H4+C2H253447000002.00E+14C6H5CH2=C2H2+C5H55333, adj8360002.00E+14C6H5CH2=C4H4+C3H35323898203.00E+13C6H5+O2=p-C6H4O2+H5312
008.50E+13C6H5O+O=p-C6H4O2+H5301
cal (mol K) -1cc (mol s)-
1
E bA ReactionReaction Number
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Modified ModelComparison to High Pressure DataФ=1,
610 bar, [C6
H5
CH3
]o
=12 ppmФ=5,
610 bar, [C6
H5
CH3
]o
=14 ppm
Experimental Modified KBG 2 KBG
1250 1300 1350 1400 1450 15002
4
6
8
10
12
14
[C6H
5CH
3] /p
pmT5/ K
1240 1280 1320 1360
2
4
6
8
10
12
14
[C6H
5CH
3] /p
pm
T5/ K
R. Sivaramakrishnan, R.S. Tranter, K. Brezinsky., Proc. of the Comb. Inst., 30, 2005, 1165–1173
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Summary
HPSTDetermine ignition delayExamine pyrolytic and oxidative chemistrySurrogate components, component mixtures of increasing complexity and real fuelsInitial studies: n-propyl benzene, 1,3,5 trimethyl benzene
Experimental ConditionsHigh pressures (10-40atm)Temperature (800-2500K)Equivalence ratios (0.5-4)Residence times (0.5-3.0msec)
GC and GC/MS will analyze gas samples
Slide Number 1�Single Pulse Shock Tube Slide Number 4Heating the Shock TubeGC and GC/MSSlide Number 7Reaction TimeSlide Number 9Well Characterized Shock Tube for Chemical Kinetic Studies under Non-ideal ConditionsIgnition DelayExamplesBenzene PyrolysisSlide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Model ModificationsSlide Number 20Summary