Pure rotational CARS measurements of temperature and O2-concentration in a low swirl turbulent premixed flame
Bohlin, Alexis LU ; Nordström, Emil LU ; Carlsson, Henning LU ; Bai, Xue-Song LU and Bengtsson, Per-Erik LU
(2013)
In Proceedings of the Combustion Institute
34.
p.3629-3636
- Abstract
- Abstract in Undetermined
Temperature and relative O-2-concentrations have been measured using pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) in a low swirl turbulent premixed flame. This lean flame burning methane has previously been investigated using laser diagnostic techniques and numerical modeling of flame characteristics. In the present work, single-shot RCARS measurements were performed and analysed statistically to obtain temperature and O-2-concentration probability density functions. The results were compared with large eddy simulations (LES) showing fairly good agreement. The rotational CARS technique was successfully applied in the whole range of temperatures (300-1700 K) and relative O-2-concentrations... (More) - Abstract in Undetermined
Temperature and relative O-2-concentrations have been measured using pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) in a low swirl turbulent premixed flame. This lean flame burning methane has previously been investigated using laser diagnostic techniques and numerical modeling of flame characteristics. In the present work, single-shot RCARS measurements were performed and analysed statistically to obtain temperature and O-2-concentration probability density functions. The results were compared with large eddy simulations (LES) showing fairly good agreement. The rotational CARS technique was successfully applied in the whole range of temperatures (300-1700 K) and relative O-2-concentrations (9-21%), and based on the simultaneous measurements of temperature and O-2-concentration an improved understanding of the reaction progress and air entrainment from the surroundings can be achieved. From the evaluated O-2-concentration, the H2O mole fraction could be estimated, which subsequently made an important thermometric correction possible of up to similar to 40 K at 1700 K by inclusion of N-2-H2O line-broadening coefficients in the theoretical spectral calculations. Spatial averaging effects were observed in a fraction of spectra where both hot and cold spectral envelopes were detected, most often with corresponding peaks displaced relative to each other. The large range of CARS signal intensities (about 3 orders of magnitude) when intermittently probing low and high temperature gases was dealt with by using a multi-track function of the CCD camera that increased the dynamic range. Merits and limitations of pure rotational CARS for diagnostics in turbulent flames are discussed and comparison is made with vibrational CARS. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/3290283
- author
- Bohlin, Alexis
LU
; Nordström, Emil
LU
; Carlsson, Henning
LU
; Bai, Xue-Song
LU
and Bengtsson, Per-Erik
LU
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Thermometry, Rotational coherent anti-Stokes Raman spectroscopy, O-2-Concentration measurements, Turbulent flame, Large eddy simulations
- in
- Proceedings of the Combustion Institute
- volume
- 34
- pages
- 3629 - 3636
- publisher
- Elsevier
- external identifiers
-
- wos:000313131800197
- scopus:84872018251
- ISSN
- 1540-7489
- DOI
- 10.1016/j.proci.2012.05.016
- language
- English
- LU publication?
- yes
- id
- 67885ae5-fdc6-4e40-99ce-a69913b8d0a5 (old id 3290283)
- date added to LUP
- 2016-04-01 10:50:36
- date last changed
- 2022-02-25 06:13:16
@article{67885ae5-fdc6-4e40-99ce-a69913b8d0a5,
abstract = {{Abstract in Undetermined<br/>Temperature and relative O-2-concentrations have been measured using pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) in a low swirl turbulent premixed flame. This lean flame burning methane has previously been investigated using laser diagnostic techniques and numerical modeling of flame characteristics. In the present work, single-shot RCARS measurements were performed and analysed statistically to obtain temperature and O-2-concentration probability density functions. The results were compared with large eddy simulations (LES) showing fairly good agreement. The rotational CARS technique was successfully applied in the whole range of temperatures (300-1700 K) and relative O-2-concentrations (9-21%), and based on the simultaneous measurements of temperature and O-2-concentration an improved understanding of the reaction progress and air entrainment from the surroundings can be achieved. From the evaluated O-2-concentration, the H2O mole fraction could be estimated, which subsequently made an important thermometric correction possible of up to similar to 40 K at 1700 K by inclusion of N-2-H2O line-broadening coefficients in the theoretical spectral calculations. Spatial averaging effects were observed in a fraction of spectra where both hot and cold spectral envelopes were detected, most often with corresponding peaks displaced relative to each other. The large range of CARS signal intensities (about 3 orders of magnitude) when intermittently probing low and high temperature gases was dealt with by using a multi-track function of the CCD camera that increased the dynamic range. Merits and limitations of pure rotational CARS for diagnostics in turbulent flames are discussed and comparison is made with vibrational CARS. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.}},
author = {{Bohlin, Alexis and Nordström, Emil and Carlsson, Henning and Bai, Xue-Song and Bengtsson, Per-Erik}},
issn = {{1540-7489}},
keywords = {{Thermometry; Rotational coherent anti-Stokes Raman spectroscopy; O-2-Concentration measurements; Turbulent flame; Large eddy simulations}},
language = {{eng}},
pages = {{3629--3636}},
publisher = {{Elsevier}},
series = {{Proceedings of the Combustion Institute}},
title = {{Pure rotational CARS measurements of temperature and O2-concentration in a low swirl turbulent premixed flame}},
url = {{http://dx.doi.org/10.1016/j.proci.2012.05.016}},
doi = {{10.1016/j.proci.2012.05.016}},
volume = {{34}},
year = {{2013}},
}