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Title: DUAL-PUMP CARS THERMOMETRY IN HEAVILY SOOTING FLAMES.

Abstract

Abstract not provided.

Authors:
;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1137268
Report Number(s):
SAND2007-1531J
Journal ID: ISSN 0001--1452; 523689
DOE Contract Number:
DE-AC04-94AL85000
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIAA JOURNAL; Journal Volume: 45; Journal Issue: 12; Related Information: Proposed for publication in AIAA JOURNAL.
Country of Publication:
United States
Language:
English

Citation Formats

Kearney, Sean P., and Jackson, Matthew N. DUAL-PUMP CARS THERMOMETRY IN HEAVILY SOOTING FLAMES.. United States: N. p., 2007. Web. doi:10.2514/1.31054.
Kearney, Sean P., & Jackson, Matthew N. DUAL-PUMP CARS THERMOMETRY IN HEAVILY SOOTING FLAMES.. United States. doi:10.2514/1.31054.
Kearney, Sean P., and Jackson, Matthew N. Thu . "DUAL-PUMP CARS THERMOMETRY IN HEAVILY SOOTING FLAMES.". United States. doi:10.2514/1.31054.
@article{osti_1137268,
title = {DUAL-PUMP CARS THERMOMETRY IN HEAVILY SOOTING FLAMES.},
author = {Kearney, Sean P. and Jackson, Matthew N},
abstractNote = {Abstract not provided.},
doi = {10.2514/1.31054},
journal = {AIAA JOURNAL},
number = 12,
volume = 45,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • No abstract prepared.
  • Dual-pump coherent anti-Stokes Raman scattering (CARS) is used to measure temperature and species profiles in representative non-premixed and partially-premixed CH{sub 4}/O{sub 2}/N{sub 2} flames. A new laser system has been developed to generate a tunable single-frequency beam for the second pump beam in the dual-pump N{sub 2}-CO{sub 2} CARS process. The second harmonic output ({proportional_to}532 nm) from an injection-seeded Nd:YAG laser is used as one of the narrowband pump beams. The second single-longitudinal-mode pump beam centered near 561 nm is generated using an injection-seeded optical parametric oscillator, consisting of two non-linear {beta}-BBO crystals, pumped using the third harmonic output ({proportional_to}355more » nm) of the same Nd:YAG laser. A broadband dye laser (BBDL), pumped using the second harmonic output of an unseeded Nd:YAG laser, is employed to produce the Stokes beam centered near 607 nm with full-width-at-half-maximum of {proportional_to}250 cm{sup -1}. The three beams are focused between two opposing nozzles of a counter-flow burner facility to measure temperature and major species concentrations in a variety of CH{sub 4}/O{sub 2}/N{sub 2} non-premixed and partially-premixed flames stabilized at a global strain rate of 20 s{sup -1} at atmospheric-pressure. For the non-premixed flames, excellent agreement is observed between the measured profiles of temperature and CO{sub 2}/N{sub 2} concentration ratios with those calculated using an opposed-flow flame code with detailed chemistry and molecular transport submodels. For partially-premixed flames, with the rich side premixing level beyond the stable premixed flame limit, the calculations overestimate the distance between the premixed and the non-premixed flamefronts. Consequently, the calculated temperatures near the rich, premixed flame are higher than those measured. Accurate prediction of the distance between the premixed and the non-premixed flames provides an interesting challenge for future computations. (author)« less
  • The application of nitrogen vibrational CARS thermometry to sooty, premixed, atmospheric pressure flames has been investigated using a Nd:YAG laser based system. It was found that laser-produced C{sub 2} radicals strongly absorb part of the fundamental band peak in the CARS spectrum. This was the most severe interference to the CARS signal. A quantitative investigation of temperature errors caused by the C{sub 2} absorption effect is presented. The correlation between the absorption interference and the soot volume fraction was examined for different flame conditions. Also, the increase of the nonresonant susceptibility in sooty flame regions is clearly illustrated and itsmore » effect on the evaluated temperature is quantitatively determined. The single-shot temperature standard deviation has also been investigated in flames with different soot loadings. Finally, other interference effects to the CARS signals in sooty flames are described and discussed.« less
  • Dual-broadband rotational coherent anti-Stokes Raman spectroscopy (DB-RCARS) has been investigated for thermometry under high-pressure and high-temperature conditions, in the product gas of fuel-lean hydrocarbon flames up to 1 MPa. Initial calibration measurements made in nitrogen, oxygen, and air, at pressures up to 1.55 MPa and temperatures up to 1800 K, showed good agreement between experimental and theoretical spectra. In the high-pressure flames, high-quality single-shot spectra were recorded in which nitrogen lines dominated, and peaks from CO{sub 2} and O{sub 2} were also visible. A spectral model including the species N{sub 2}, CO{sub 2}, and O{sub 2}, as well as themore » best available Raman linewidth models for flame thermometry, were used to evaluate the experimental spectra. Experimental problems as well as considerations related to the spectral evaluation are discussed. This work demonstrates the significant potential of DB-RCARS thermometry for applications in high-pressure and high-temperature environments. (author)« less