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This content will become publicly available on August 10, 2017

Title: Multiparameter spatio-thermochemical probing of flame–wall interactions advanced with coherent Raman imaging

Ultrabroadband coherent anti-Stokes Ra man spectroscopy (CARS) has been developed for one -dimensional imaging of temperature and major species distributions simultaneously in the near-wall region of a methane/air flame supported on a side-wall-quenching (SWQ) burner. Automatic temporal and spatial overlap of the ~7 femtosecond pump and Stokes pulses is achieved utilizing a two-beam CARS phase-matching scheme, and the crossed ~75 picosecond probe beam provide s excellent spatial sectioning of the probed location. Concurrent detection of N2, O2, H2, CO, CO2, and CH4 is demonstrated while high-fidelity flame thermometry is assessed from the N2 pure rotational S-branch in a one-dimensional -CARS imaging configuration. A methane/air premixed flame at lean, stoichiometric, and rich conditions ( Φ = 0.83, 1.0 , and 1.2) and Reynolds number = 5,000 is probed as it quenches against a cooled steel side- wall parallel to the flow providing a persistent flame-wall interaction. Here, an imaging resolution of better than 40 μm is achieved across the field -of-view, thus allowing thermochemical states (temperature and major species) of the thermal boundary layer to be resolved to within ~30 μm of the interface.
Authors:
 [1] ;  [2] ;  [1] ;  [2] ;  [1]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  2. Technische Univ. Darmstadt (Germany). Institute of Reactive Flows and Diagnostics (RSM)
Publication Date:
OSTI Identifier:
1251595
Report Number(s):
SAND--2016-0939J
Journal ID: ISSN 1540-7489; 619046
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Proceedings of the Combustion Institute
Additional Journal Information:
Journal Name: Proceedings of the Combustion Institute; Journal ID: ISSN 1540-7489
Publisher:
Elsevier
Research Org:
Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY time-resolved spectroscopy; CARS; coherent imaging; thermochemical states; flame-wall interactions; combustion diagnostics