Dual-pump CARS temperature and major species concentration measurements in counter-flow methane flames using narrowband pump and broadband Stokes lasers

Journal Article · Thu Jul 15 04:00:00 EDT 2010 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2010.03.002· OSTI ID:21328639

Thariyan, Mathew P; Ananthanarayanan, Vijaykumar; Bhuiyan, Aizaz H; Naik, Sameer V; Gore, Jay P; Lucht, Robert P ^[1]

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1. School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)

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}355 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)

• OSTI ID: 21328639
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 7 Vol. 157; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ATMOSPHERIC PRESSURE
CALCULATION METHODS
CARBON DIOXIDE
CHEMICAL COMPOSITION
CONCENTRATION RATIO
COUNTERFLOW SYSTEMS
DISTANCE
Dual-pump CARS
FORECASTING
LAMINAR FLAMES
Laminar counter-flow flames
Laser diagnostics
METHANE
NITROGEN
NONLINEAR PROBLEMS
Non-premixed flames
OXYGEN
Partially-premixed flames
RAMAN EFFECT
TEMPERATURE DISTRIBUTION
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K