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Simultaneous measurements of velocity and concentration of gas flow using femtosecond laser-induced chemiluminescence

Han, Lei ; Gao, Qiang LU ; Li, Bo LU ; Li, Ming ; Zhang, Dayuan ; Bai, Xuesong and Li, Zhongshan LU (2022) In Optics and Lasers in Engineering 155.
Abstract

The mixing process in a gas flow plays a crucial role in chemical reactions, and simultaneous measurements of both velocity and mixture fraction are desired to fathom the process. Here, we report a scheme for simultaneously measuring both velocity and concentration by femtosecond laser-induced chemiluminescence. The femtosecond laser would induce chemical reactions that generate CN radicals in the B state. The transition of CN (X-B) would emit fluorescence with both strong intensity and long duration, and the decay of the fluorescence versus time showed prominent benefits for the simultaneous measurement. This measurement was accomplished by an ICCD camera worked in the on-chip multi-exposure mode, i.e., the camera had two exposures in... (More)

The mixing process in a gas flow plays a crucial role in chemical reactions, and simultaneous measurements of both velocity and mixture fraction are desired to fathom the process. Here, we report a scheme for simultaneously measuring both velocity and concentration by femtosecond laser-induced chemiluminescence. The femtosecond laser would induce chemical reactions that generate CN radicals in the B state. The transition of CN (X-B) would emit fluorescence with both strong intensity and long duration, and the decay of the fluorescence versus time showed prominent benefits for the simultaneous measurement. This measurement was accomplished by an ICCD camera worked in the on-chip multi-exposure mode, i.e., the camera had two exposures in succession to capture two luminescent lines on one image. The first line was used to measure the methane concentration and hence, the mixture fraction through a calibration procedure. The second line was the first line displaced by the flow in a known time interval and we demonstrate an algorithm to derive the one dimensional-two components velocity fields from the line shapes of the luminescent lines. The detection limit of the concentration is estimated to be 152 ppm and the minimum measurable velocity is estimated to be 5 m/s.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
chemiluminescence, concentration, simultaneous measurement, velocity field
in
Optics and Lasers in Engineering
volume
155
article number
107060
publisher
Elsevier
external identifiers
  • scopus:85127326461
ISSN
0143-8166
DOI
10.1016/j.optlaseng.2022.107060
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2022
id
fdf052ed-b4ca-47fa-8a54-f1ed1115f5e2
date added to LUP
2022-05-06 08:15:48
date last changed
2022-05-12 09:31:01
@article{fdf052ed-b4ca-47fa-8a54-f1ed1115f5e2,
  abstract     = {{<p>The mixing process in a gas flow plays a crucial role in chemical reactions, and simultaneous measurements of both velocity and mixture fraction are desired to fathom the process. Here, we report a scheme for simultaneously measuring both velocity and concentration by femtosecond laser-induced chemiluminescence. The femtosecond laser would induce chemical reactions that generate CN radicals in the B state. The transition of CN (X-B) would emit fluorescence with both strong intensity and long duration, and the decay of the fluorescence versus time showed prominent benefits for the simultaneous measurement. This measurement was accomplished by an ICCD camera worked in the on-chip multi-exposure mode, i.e., the camera had two exposures in succession to capture two luminescent lines on one image. The first line was used to measure the methane concentration and hence, the mixture fraction through a calibration procedure. The second line was the first line displaced by the flow in a known time interval and we demonstrate an algorithm to derive the one dimensional-two components velocity fields from the line shapes of the luminescent lines. The detection limit of the concentration is estimated to be 152 ppm and the minimum measurable velocity is estimated to be 5 m/s.</p>}},
  author       = {{Han, Lei and Gao, Qiang and Li, Bo and Li, Ming and Zhang, Dayuan and Bai, Xuesong and Li, Zhongshan}},
  issn         = {{0143-8166}},
  keywords     = {{chemiluminescence; concentration; simultaneous measurement; velocity field}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Optics and Lasers in Engineering}},
  title        = {{Simultaneous measurements of velocity and concentration of gas flow using femtosecond laser-induced chemiluminescence}},
  url          = {{http://dx.doi.org/10.1016/j.optlaseng.2022.107060}},
  doi          = {{10.1016/j.optlaseng.2022.107060}},
  volume       = {{155}},
  year         = {{2022}},
}