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Campbell MF, Bohlin GA, Schrader PE, Bambha RP, Kliewer CJ, Johansson KO, Michelsen HA. Design and characterization of a linear Hencken-type burner. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:115114. [PMID: 27910522 DOI: 10.1063/1.4967491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have designed and constructed a Hencken-type burner that produces a 38-mm-long linear laminar partially premixed co-flow diffusion flame. This burner was designed to produce a linear flame for studies of soot chemistry, combining the benefit of the conventional Hencken burner's laminar flames with the advantage of the slot burner's geometry for optical measurements requiring a long interaction distance. It is suitable for measurements using optical imaging diagnostics, line-of-sight optical techniques, or off-axis optical-scattering methods requiring either a long or short path length through the flame. This paper presents details of the design and operation of this new burner. We also provide characterization information for flames produced by this burner, including relative flow-field velocities obtained using hot-wire anemometry, temperatures along the centerline extracted using direct one-dimensional coherent Raman imaging, soot volume fractions along the centerline obtained using laser-induced incandescence and laser extinction, and transmission electron microscopy images of soot thermophoretically sampled from the flame.
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Affiliation(s)
- M F Campbell
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - G A Bohlin
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - P E Schrader
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - R P Bambha
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - C J Kliewer
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - K O Johansson
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
| | - H A Michelsen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94550, USA
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Quantification of OH and HO2 radicals during the low-temperature oxidation of hydrocarbons by Fluorescence Assay by Gas Expansion technique. Proc Natl Acad Sci U S A 2013; 110:20014-7. [PMID: 24277836 DOI: 10.1073/pnas.1314968110] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
•OH and •HO2 radicals are known to be the key species in the development of ignition. A direct measurement of these radicals under low-temperature oxidation conditions (T = 550-1,000 K) has been achieved by coupling a technique named fluorescence assay by gas expansion, an experimental technique designed for the quantification of these radicals in the free atmosphere, to a jet-stirred reactor, an experimental device designed for the study of low-temperature combustion chemistry. Calibration allows conversion of relative fluorescence signals to absolute mole fractions. Such radical mole fraction profiles will serve as a benchmark for testing chemical models developed to improve the understanding of combustion processes.
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Brumfield B, Sun W, Ju Y, Wysocki G. Direct In Situ Quantification of HO2 from a Flow Reactor. J Phys Chem Lett 2013; 4:872-876. [PMID: 26291349 DOI: 10.1021/jz400143c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The first direct in situ measurements of hydroperoxyl radical (HO2) at atmospheric pressure from the exit of a laminar flow reactor have been carried out using mid-infrared Faraday rotation spectroscopy. HO2 was generated by oxidation of dimethyl ether, a potential renewable biofuel with a simple molecular structure but rich low-temperature oxidation chemistry. On the basis of the results of nonlinear fitting of the experimental data to a theoretical spectroscopic model, the technique offers an estimated sensitivity of <1 ppmv over a reactor exit temperature range of 398-673 K. Accurate in situ measurement of this species will aid in quantitative modeling of low-temperature and high-pressure combustion kinetics.
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Affiliation(s)
- Brian Brumfield
- †Department of Electrical Engineering and ‡Department of Mechanical and Aerospace Engineering, Princeton University, Engineering Quadrangle, Princeton, New Jersey 08544, United States
| | - Wenting Sun
- †Department of Electrical Engineering and ‡Department of Mechanical and Aerospace Engineering, Princeton University, Engineering Quadrangle, Princeton, New Jersey 08544, United States
| | - Yiguang Ju
- †Department of Electrical Engineering and ‡Department of Mechanical and Aerospace Engineering, Princeton University, Engineering Quadrangle, Princeton, New Jersey 08544, United States
| | - Gerard Wysocki
- †Department of Electrical Engineering and ‡Department of Mechanical and Aerospace Engineering, Princeton University, Engineering Quadrangle, Princeton, New Jersey 08544, United States
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Johansson A, Hemdal S, Andersson M, Rosén A. Determination of OH Number Densities Outside of a Platinum Catalyst Using Cavity Ringdown Spectroscopy. J Phys Chem A 2007; 111:6798-805. [PMID: 17465532 DOI: 10.1021/jp069061v] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is demonstrated that cavity ringdown spectroscopy (CRDS) can be used to probe reaction intermediates desorbing from the surface during a heterogeneous catalytic reaction and provide information valuable in understanding the reaction kinetics. During water formation from H2 and O2, desorbed OH molecules outside of a polycrystalline platinum catalyst were quantified as a function of the relative hydrogen concentration, alphaH2 using CRDS. The temperature of the catalyst was 1500 K, the total pressure was 26 Pa, and the flow was set to 100 sccm. At a distance of 6.5 mm from the Pt catalyst, the maximum OH concentration was found to be 1.5+/-0.2x10(12) cm(-3) at an alphaH2 value of 10%, and the rotational temperature was determined to be 775+/-24 K. The desorbed OH molecules were also probed using laser-induced fluorescence (LIF), and the alphaH2-dependent OH abundance was compared with the CRDS results. The relative concentration of OH probed with LIF appeared to be lower at alphaH2=30-50% compared to what was determined by CRDS. The observed discrepancy is suggested to be due to electronic quenching, as was indicated by a shorter fluorescence lifetime at alphaH2=30% compared to at alphaH2=10%.
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Affiliation(s)
- Asa Johansson
- Department of Physics, Göteborg University, SE-41296 Göteborg, Sweden
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Schocker A, Kohse-Höinghaus K, Brockhinke A. Quantitative determination of combustion intermediates with cavity ring-down spectroscopy: systematic study in propene flames near the soot-formation limit. APPLIED OPTICS 2005; 44:6660-72. [PMID: 16270555 DOI: 10.1364/ao.44.006660] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cavity ring-down spectroscopy (CRDS) was applied in several fuel-rich, one-dimensional, premixed C3H6/O2/Ar flames at 50 mbars (37.5 torr) to measure absolute OH, HCO, and 1CH2 concentration as well as temperature as a function of stoichiometry. Although these flames near the sooting limit present a complex chemical environment, significant spectral interferences were found to be absent. Specific aspects of the CRDS technique for measurement of temperature and radical concentration profiles are discussed; and the results are analyzed in comparison with flame model simulations.
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Affiliation(s)
- Alexander Schocker
- Universität Bielefeld, Fakultät für Chemie, Physikalische Chemie I, Universitätsstrasse 25, D-33615 Bielefeld, Germany
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Wang C, Mazzotti FJ, Koirala SP, Winstead CB, Miller GP. Measurements of OH radicals in a low-power atmospheric inductively coupled plasma by cavity ringdown spectroscopy. APPLIED SPECTROSCOPY 2004; 58:734-740. [PMID: 15198827 DOI: 10.1366/000370204873015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cavity ringdown spectroscopy is applied to line-of-sight measurements of OH radicals in an atmospheric-pressure argon inductively coupled plasma, operating at low power (200 W) and low gas flows (approximately 18 liters/min). Density populations of the single S21(1) rotational line in the OH A2sigma(+)-X2Pi (0-0) band are extracted from the measured line-of-sight absorbance. Plasma gas kinetic temperatures, derived from the recorded line shapes of the S21(1) line, ranged from 1858 to 2000 K with an average uncertainty of 10%. Assuming local thermodynamic equilibrium, an assumption supported by the comparison of the experimental and simulated spectra, the spatially averaged total OH number density at different observation heights was determined to be in the range of 1.7 x 10(20)-8.5 x 10(20) (m(-3)) with the highest OH density in the plasma tail. This work demonstrates that ringdown spectra of the OH radical may be used both as a thermometer for high-temperature environments and as a diagnostic tool to probe the thermodynamic properties of plasmas.
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Affiliation(s)
- Chuji Wang
- Diagnostic Instrumentation & Analysis Laboratory, Mississippi State University, 205 Research Blvd., Starkville, Mississippi 39759, USA.
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Spuler S, Linne M. Numerical analysis of beam propagation in pulsed cavity ring-down spectroscopy. APPLIED OPTICS 2002; 41:2858-2868. [PMID: 12027173 DOI: 10.1364/ao.41.002858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A numerical simulation of pulsed cavity ring-down spectroscopy (CRDS) is developed with the commercially available software package GENERAL LASER ANALYSIS AND DESIGN. The model is verified through a series of numerical experiments. Several issues of concern in CRDS are investigated, including spatial resolution, misalignment, non-Gaussian beam input, and the effect of flames inside a ring-down cavity. Suggestions for the design of pulsed CRDS instruments are provided.
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Affiliation(s)
- Scott Spuler
- Division of Engineering, Colorado School of Mines, Golden 80401, USA.
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Mercier X, Jamette P, Pauwels J, Desgroux P. Absolute CH concentration measurements by cavity ring-down spectroscopy in an atmospheric diffusion flame. Chem Phys Lett 1999. [DOI: 10.1016/s0009-2614(99)00416-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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