Laser ignition and flame characteristics of pulsed methane jets in homogeneous isotropic turbulence without mean flow
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Published version
Author(s)
Sung, Y
Charalampous, G
Hardalupas, I
Choi, G
Type
Journal Article
Abstract
The influence of turbulence on the minimum ignition energy (MIE) and ignited flame characteristics is investigated for pulsed methane diffusion jets ignited by laser-induced plasma. The methane jet is injected in a volume of homogeneous and isotropic air turbulence without mean flow, with the level of turbulence being controlled independently. The study is carried out for a range of fuel jet (Rejet) Reynolds number, namely 1000, 2000, and 3000, and a range of turbulent (Reλ) Reynolds number, namely 0–207. The results show that the position of the maximum intensity of flame emission was randomly scattered due to the fact that the ignited flame is deflected from the nozzle axis by the turbulent velocity fluctuations. The effect is more profound at higher Rejet. The value of the MIE, determined according to 50% ignitibility of mixture, increases by a factor of 2 for an increase of Reλ from 0 to 207 and by a factor of 5 for an increase of Rejet from 1000 to 3000. Two trends are observed on MIE with Reλ. For low Reλ, MIE is independent of Reλ. Past a critical value of Reλ, MIE increases as a linear function of Reλ. This transition occurs at critical values of Reλ,c = 158, 197 and 202 for Rejet= 1000, 2000 and 3000, respectively. The mean value of MIE for ignition before and after transition is a linear function of Rejet. The difference between the mean value of MIE before transition and after transition is around 5 mJ for all considered Rejet.
Date Issued
2016-10-13
Date Acceptance
2016-07-27
Citation
Proceedings of the Combustion Institute, 2016, 36 (2), pp.1653-1660
ISSN
1873-2704
Publisher
Elsevier
Start Page
1653
End Page
1660
Journal / Book Title
Proceedings of the Combustion Institute
Volume
36
Issue
2
Copyright Statement
© 2016 The Author(s). Published by Elsevier Inc. on behalf of The Combustion Institute.
This is an open access article under the CC BY-NC-ND license.
(http://creativecommons.org/licenses/by-nc-nd/4.0/)
This is an open access article under the CC BY-NC-ND license.
(http://creativecommons.org/licenses/by-nc-nd/4.0/)
Subjects
Science & Technology
Physical Sciences
Technology
Thermodynamics
Energy & Fuels
Engineering, Chemical
Engineering, Mechanical
Engineering
Laser ignition
Homogeneous and isotropic turbulence
Pulsed jet
Diffusion flame
Minimum ignition energy
INDUCED SPARK-IGNITION
AIR MIXTURES
PREMIXED FLAMES
DISTRIBUTED REGIMES
DIFFUSION FLAMES
ENERGY
COMBUSTION
TRANSITION
0902 Automotive Engineering
0904 Chemical Engineering
0913 Mechanical Engineering
Publication Status
Published