Christopher Strand
Senior Research Engineer
Mechanical Engineering
Academic Appointments
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Sr Research Engineer, Mechanical Engineering
All Publications
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Measurement of hydrogen and nitrogen via collision-induced infrared absorption
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
2024; 93: 364-373
View details for DOI 10.1016/j.ijhydene.2024.10.318
View details for Web of Science ID 001350370000001
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Collisional broadening and pressure shift coefficients for the potassium D1 and D2 transitions in oxygen and carbon dioxide at high temperatures
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2024; 328
View details for DOI 10.1016/j.jqsrt.2024.109152
View details for Web of Science ID 001299285700001
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Shock-Layer Measurements in T5 Shock Tunnel Hypersonic Flows Around a Cylinder Model
AIAA JOURNAL
2024
View details for DOI 10.2514/1.J063877
View details for Web of Science ID 001296258800001
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Experimental temperature- and pressure-dependent absorbance cross sections and a pseudo-line-list model for methyl formate near 5.7 . 7 μm
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2024; 327
View details for DOI 10.1016/j.jqsrt.2024.109128
View details for Web of Science ID 001293622800001
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A laser diagnostic for lineshape-based gas temperature and pressure measurements targeting a single atomic potassium absorption transition
APPLIED PHYSICS B-LASERS AND OPTICS
2024; 130 (7)
View details for DOI 10.1007/s00340-024-08252-7
View details for Web of Science ID 001242906600001
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Development of a vapor-based method for seeding alkali metals in shock tube facilities
SHOCK WAVES
2024; 34 (1): 61-67
View details for DOI 10.1007/s00193-024-01165-6
View details for Web of Science ID 001207728800004
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Fiber-coupled optical probe for laser absorption diagnostics in shock tube experiments with high concentrations of non-monatomic species
PROCEEDINGS OF THE COMBUSTION INSTITUTE
2024; 40 (1-4)
View details for DOI 10.1016/j.proci.2024.105483
View details for Web of Science ID 001273551200001
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Laser Absorption Sensor Targeting Potassium for Hypersonic Velocity, Temperature, and Enthalpy Measurements
AIAA JOURNAL
2023
View details for DOI 10.2514/1.J062620
View details for Web of Science ID 001003665400001
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Shock-Tube Measurements of Atomic Nitrogen Collisional Excitation in 8000-12000 K Partially Ionized Nitrogen-Argon Mixtures.
The journal of physical chemistry. A
2023
Abstract
We report on shock-tube experiments measuring the collisional excitation of atomic nitrogen using tunable diode laser absorption spectroscopy (TDLAS). Conditions behind the reflected shocks ranged from 8000 to 12000 K and 0.1 to 1.1 atm in mixtures of 1 or 2% molecular nitrogen (N2) in argon (Ar). Absorption from the transition between atomic nitrogen quantum states 4P to 4D at 868 nm was used to monitor the formation of electronically excited nitrogen. Population measurements of the 4P state were made at a rate of 50 kHz. In connection with these measurements, a multitemperature kinetic mechanism is proposed for nitrogen excitation. Measurements suggest a multistage process. In early test times, a period of induction due to N2 dissociation is followed by a rise via heavy particle excitation. The dominant channel causing this excitation is believed to be N + N N(4P) + N with a measured forward rate constant of 3.65 * 10-18 exp(-119892/T) [m3/s]. As test time evolves, the excitation of 4P, referred to as N*, is subsequently interrupted and then resumes, as the kinetic environment becomes increasingly electron-dominated. The most impactful reactions of the mechanism are optimized to reduce the residual between simulations and the measurements. The measured N* populations indicate strong, though indirect, sensitivity to adjacent processes, including the excitation of metastable nitrogen, and ionization channels.
View details for DOI 10.1021/acs.jpca.2c07839
View details for PubMedID 36745871
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Measurements of T5 Shock Tunnel Freestream Temperature, Velocity, and Composition
AIAA JOURNAL
2023
View details for DOI 10.2514/1.J062383
View details for Web of Science ID 000924854700001
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A laser-absorption sensor for in situ detection of biofuel blend vapor in engine intakes
PROCEEDINGS OF THE COMBUSTION INSTITUTE
2023; 39 (1): 1307-1316
View details for DOI 10.1016/j.proci.2022.07.110
View details for Web of Science ID 001019044900001
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Line mixing study of carbon monoxide near 4.7 mu m broadened by nitrogen, helium, and hydrogen
JOURNAL OF MOLECULAR SPECTROSCOPY
2022; 390
View details for DOI 10.1016/j.jms.2022.111699
View details for Web of Science ID 000904449500001
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Collisional broadening and pressure shift of the potassium resonance doublets by nitrogen, helium, and hydrogen at high temperatures
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2022; 283
View details for DOI 10.1016/j.jqsrt.2022.108149
View details for Web of Science ID 000792886800015
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Investigating Arcjet Mixing and Enthalpy Loss Using Atomic Oxygen Laser Absorption Spectroscopy
AIAA JOURNAL
2022; 60 (2): 976-984
View details for DOI 10.2514/1.J060274
View details for Web of Science ID 000802220400034
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Line mixing study on the fundamental rovibrational band of nitric oxide near 5.3 mu m
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2022; 278
View details for DOI 10.1016/j.jqsrt.2021.107997
View details for Web of Science ID 000748572100014
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Measurements of Reflected Shock Tunnel Freestream Nitric Oxide Temperatures and Partial Pressure
AIAA JOURNAL
2021; 59 (12): 5266-5275
View details for DOI 10.2514/1.J060596
View details for Web of Science ID 000800025200032
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Thermometry and speciation for high-temperature and -pressure methane pyrolysis using shock tubes and dual-comb spectroscopy
MEASUREMENT SCIENCE AND TECHNOLOGY
2021; 32 (12)
View details for DOI 10.1088/1361-6501/ac22ef
View details for Web of Science ID 000702061800001
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Line mixing in the nitric oxide R-branch near 5.2 mu m at high pressures and temperatures: Measurements and empirical modeling using energy gap fitting
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2021; 276
View details for DOI 10.1016/j.jqsrt.2021.107935
View details for Web of Science ID 000709765300010
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Shock tube measurements of high-temperature argon broadening and shift parameters for the potassium D1 and D2 resonance transitions
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2021; 275
View details for DOI 10.1016/j.jqsrt.2021.107895
View details for Web of Science ID 000704000000003
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Quantum-cascade-laser-based dual-comb thermometry and speciation at high temperatures
MEASUREMENT SCIENCE AND TECHNOLOGY
2021; 32 (3)
View details for DOI 10.1088/1361-6501/abc029
View details for Web of Science ID 000621888000001
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Scientific accomplishments and research avenues of Professor Ronald Hanson
COMBUSTION AND FLAME
2021; 224: 2–5
View details for DOI 10.1016/j.combustflame.2020.08.039
View details for Web of Science ID 000609127800002
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Development of a Stark shift measurement technique using excited-state oxygen atoms to determine electron number density in shock heated O-2/Ar above 10 000 K
PLASMA SOURCES SCIENCE & TECHNOLOGY
2021; 30 (2)
View details for DOI 10.1088/1361-6595/abdd12
View details for Web of Science ID 000625362300001
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Time-resolved, single-ended laser absorption thermometry and H2O, CO2, and CO speciation in a H-2/C2H4-fueled rotating detonation engine
PROCEEDINGS OF THE COMBUSTION INSTITUTE
2021; 38 (1): 1719-1727
View details for DOI 10.1016/j.proci.2020.06.125
View details for Web of Science ID 000668887400018
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An In Situ Laser-Absorption Sensor for Crank Angle-Resolved Temperature, Pressure, and Humidity in Intake-Runner Flows
SAE INTERNATIONAL JOURNAL OF ENGINES
2021; 14 (4): 551-568
View details for DOI 10.4271/03-14-04-0034
View details for Web of Science ID 000739430500007
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Temperature-dependent absorption cross section measurements for propene, 1-butene, cis-/trans-2-butene, isobutene and 1,3-butadiene in the spectral region 8.4-11.7 mu m
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2020; 255
View details for DOI 10.1016/j.jqsrt.2020.107240
View details for Web of Science ID 000581971300017
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Two-color frequency-multiplexed IMS technique for gas thermometry at elevated pressures
APPLIED PHYSICS B-LASERS AND OPTICS
2020; 126 (3)
View details for DOI 10.1007/s00340-020-7396-4
View details for Web of Science ID 000519937700002
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Analysis of laser absorption gas sensors employing scanned-wavelength modulation spectroscopy with 1f-phase detection
APPLIED PHYSICS B-LASERS AND OPTICS
2020; 126 (1)
View details for DOI 10.1007/s00340-019-7369-7
View details for Web of Science ID 000503696100001
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Dual-comb Spectroscopy for High-temperature Reaction Kinetics
Measurement Science and Technology
2020
View details for DOI 10.1088/1361-6501/ab6ecc
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Two-temperature Collisional-radiative Modeling of Partially Ionized O2-Ar Mixtures over 8000-10,000 K Behind Reflected Shock Waves.
The journal of physical chemistry. A
2020
Abstract
The collisional excitation kinetics of atomic oxygen was studied behind reflected shock waves using tunable diode laser absorption spectroscopy. A test gas mixture of 1% O2/Ar was shock-heated to temperatures between 8000 and 10,000 K and pressures between 0.15 and 1 atm. The time evolution of the atomic oxygen population in the 3 s 5S0 state was monitored by laser absorption at 777.2 nm. The measured O(3 s 5S0) population revealed multistage behavior that was not observed in previous measurements over a temperature range of 5300-7200 K. To interpret the multistage behavior, a three-level collisional-radiative model for atomic oxygen excitation kinetics was developed. The model utilized two independent temperatures, that is, heavy particle translational temperature Ttr and electron translational temperature Te, to describe the fundamental rate constants of atomic oxygen excitation because of collisions with heavy particles and electrons, respectively. The heavy particle excitation rate was inferred from the early stage of the measurement to be k(3P →5S0) = 3.4 × 10-27 (T/K)0.5(1.061 × 105 + 2 (T/K)) exp(-1.061 × 105 K/T) ± 50% m3 s-1. The electron impact excitation rate constant of oxygen, electron impact, and heavy particle impact ionization rate constants of Argon were modified in the model to match the experimental population time histories. The modified rate parameters are also reported for the temperature range explored in the current study.
View details for DOI 10.1021/acs.jpca.0c00466
View details for PubMedID 32306734
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Calibration-free breath acetone sensor with interference correction based on wavelength modulation spectroscopy near 8.2 mu m
APPLIED PHYSICS B-LASERS AND OPTICS
2020; 126 (1)
View details for DOI 10.1007/s00340-019-7358-x
View details for Web of Science ID 000511618600001
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R-branch line intensities and temperature-dependent line broadening and shift coefficients of the nitric oxide fundamental rovibrational band
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2019; 239
View details for DOI 10.1016/j.jqsrt.2019.106612
View details for Web of Science ID 000504780100002
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High-pressure, high-temperature optical cell for mid-infrared spectroscopy
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2019; 231: 69–78
View details for DOI 10.1016/j.jqsrt.2019.04.014
View details for Web of Science ID 000469898100009
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A two-wavelength ethylene-absorption temperature diagnostic
MEASUREMENT SCIENCE AND TECHNOLOGY
2019; 30 (3)
View details for DOI 10.1088/1361-6501/ab02cf
View details for Web of Science ID 000459139700001
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Single-Ended Sensor for Thermometry and Speciation in Shock Tubes Using Native Surfaces
IEEE Sensors Journal
2019
View details for DOI 10.1109/JSEN.2019.2903989
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Single-ended mid-infrared laser-absorption sensor for time-resolved measurements of water concentration and temperature within the annulus of a rotating detonation engine
PROCEEDINGS OF THE COMBUSTION INSTITUTE
2019; 37 (2): 1435–43
View details for DOI 10.1016/j.proci.2018.05.021
View details for Web of Science ID 000456621500020
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Mid-infrared laser absorption spectroscopy of NO2 at elevated temperatures
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2017; 187: 364-374
View details for DOI 10.1016/j.jqsrt.2016.10.016
View details for Web of Science ID 000391899300036
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Line intensities and temperature-dependent line broadening coefficients of Q-branch transitions in the v(2) band of ammonia near 10.4 mu m
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
2016; 175: 90-99
View details for DOI 10.1016/j.jqsrt.2016.02.002
View details for Web of Science ID 000373542700009
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Line intensities and temperature-dependent line broadening coefficients of Q-branch transitions in the v2 band of ammonia near 10.4 μm.
Journal of quantitative spectroscopy & radiative transfer
2016; 175: 90-99
Abstract
We report measured line intensities and temperature-dependent broadening coefficients of NH3 with Ar, N2, O2, CO2, H2O, and NH3 for nine sQ(J,K) transitions in the ν2 fundamental band in the frequency range 961.5-967.5 cm-1. This spectral region was chosen due to the strong NH3 absorption strength and lack of spectral interference from H2O and CO2 for laser-based sensing applications. Spectroscopic parameters were determined by multi-line fitting using Voigt lineshapes of absorption spectra measured with two quantum cascade lasers in thermodynamically-controlled optical cells. The temperature dependence of broadening was measured over a range of temperatures between 300 and 600 K. These measurements aid the development of mid-infrared NH3 sensors for a broad range of gas mixtures and at elevated temperatures.
View details for DOI 10.1016/j.jqsrt.2016.02.002
View details for PubMedID 29225373
View details for PubMedCentralID PMC5722251
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Quantification of Supersonic Impulse Flow Conditions via High-Bandwidth Wavelength Modulation Absorption Spectroscopy
AIAA JOURNAL
2015; 53 (10): 2978-2987
View details for DOI 10.2514/1.J053842
View details for Web of Science ID 000361468800014
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Hypersonic Scramjet Testing via Diode Laser Absorption in a Reflected Shock Tunnel
JOURNAL OF PROPULSION AND POWER
2014; 30 (6): 1586-1594
View details for DOI 10.2514/1.B35220
View details for Web of Science ID 000344145000018
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Fitting of calibration-free scanned-wavelength-modulation spectroscopy spectra for determination of gas properties and absorption lineshapes
APPLIED OPTICS
2014; 53 (3): 356-367
Abstract
The development and initial demonstration of a scanned-wavelength, first-harmonic-normalized, wavelength-modulation spectroscopy with nf detection (scanned-WMS-nf/1f) strategy for calibration-free measurements of gas conditions are presented. In this technique, the nominal wavelength of a modulated tunable diode laser (TDL) is scanned over an absorption transition to measure the corresponding scanned-WMS-nf/1f spectrum. Gas conditions are then inferred from least-squares fitting the simulated scanned-WMS-nf/1f spectrum to the measured scanned-WMS-nf/1f spectrum, in a manner that is analogous to widely used scanned-wavelength direct-absorption techniques. This scanned-WMS-nf/1f technique does not require prior knowledge of the transition linewidth for determination of gas properties. Furthermore, this technique can be used with any higher harmonic (i.e., n>1), modulation depth, and optical depth. Selection of the laser modulation index to maximize both signal strength and sensitivity to spectroscopic parameters (i.e., gas conditions), while mitigating distortion, is described. Last, this technique is demonstrated with two-color measurements in a well-characterized supersonic flow within the Stanford Expansion Tube. In this demonstration, two frequency-multiplexed telecommunication-grade TDLs near 1.4 μm were scanned at 12.5 kHz (i.e., measurement repetition rate of 25 kHz) and modulated at 637.5 and 825 kHz to determine the gas temperature, pressure, H2O mole fraction, velocity, and absorption transition lineshape. Measurements are shown to agree within uncertainty (1%-5%) of expected values.
View details for DOI 10.1364/AO.53.000356
View details for Web of Science ID 000330172300007
View details for PubMedID 24514120
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Supersonic Mass-Flux Measurements via Tunable Diode Laser Absorption and Nonuniform Flow Modeling
49th AIAA Aerospace Sciences Meeting / New Horizons Forum and Aerospace Exposition
AMER INST AERONAUT ASTRONAUT. 2011: 2783–91
View details for DOI 10.2514/1.J051118
View details for Web of Science ID 000297968200017