Algorithmic determination of the mechanism through which H2O-dilution affects autoignition dynamics and NO formation in CH4/air mixtures

Efstathios Al Tingas; Dimitrios Kyritsis; Dimitris A. Goussis

doi:10.1016/j.fuel.2016.06.057

Algorithmic determination of the mechanism through which H₂O-dilution affects autoignition dynamics and NO formation in CH₄/air mixtures

Efstathios Al Tingas
, Dimitrios Kyritsis
, Dimitris A. Goussis

Mechanical & Nuclear Engineering

National Technical University of Athens

Research output: Contribution to journal › Article › peer-review

37 Scopus citations

Abstract

The Computational Singular Perturbation (CSP) algorithm is employed in order to determine how H₂O-dilution influences ignition delay and chemical paths that generate NO during isochoric homogenous lean CH₄/air autoignition. Regarding the ignition delay, it is shown that H₂O-dilution enhances reactivity, mainly due to the increased OH production throughout the explosive stage via reaction H₂O₂(+H₂O)→OH+OH(+H₂O). With regard to NO generation, the relative importance of thermal and chemical effects are examined and it is concluded that both are important. The thermal effects result in a lower temperature at the end of the explosive stage, while the most notable chemical effect is the lower level of O after this stage, mainly due to the effect of H₂O-dilution on the equilibrium of the reaction O+H₂O↔OH+OH. The depletion of O, together with the thermal effect, causes a substantial decrease in final NO generation.

Original language	British English
Pages (from-to)	90-98
Number of pages	9
Journal	Fuel
Volume	183
DOIs	https://doi.org/10.1016/j.fuel.2016.06.057
State	Published - 1 Nov 2016

Keywords

Autoignition
CSP
Methane
NO
Water dilution

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10.1016/j.fuel.2016.06.057

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@article{ce1b6efd5c2340dda911ea6bf91e3dce,

title = "Algorithmic determination of the mechanism through which H2O-dilution affects autoignition dynamics and NO formation in CH4/air mixtures",

abstract = "The Computational Singular Perturbation (CSP) algorithm is employed in order to determine how H2O-dilution influences ignition delay and chemical paths that generate NO during isochoric homogenous lean CH4/air autoignition. Regarding the ignition delay, it is shown that H2O-dilution enhances reactivity, mainly due to the increased OH production throughout the explosive stage via reaction H2O2(+H2O)→OH+OH(+H2O). With regard to NO generation, the relative importance of thermal and chemical effects are examined and it is concluded that both are important. The thermal effects result in a lower temperature at the end of the explosive stage, while the most notable chemical effect is the lower level of O after this stage, mainly due to the effect of H2O-dilution on the equilibrium of the reaction O+H2O↔OH+OH. The depletion of O, together with the thermal effect, causes a substantial decrease in final NO generation.",

keywords = "Autoignition, CSP, Methane, NO, Water dilution",

author = "Tingas, \{Efstathios Al\} and Dimitrios Kyritsis and Goussis, \{Dimitris A.\}",

note = "Funding Information: DCK and DAG gratefully acknowledge support of the Khalifa University Internal Research Fund (KUIRF 2). Publisher Copyright: {\textcopyright} 2016 Elsevier Ltd.",

year = "2016",

month = nov,

day = "1",

doi = "10.1016/j.fuel.2016.06.057",

language = "British English",

volume = "183",

pages = "90--98",

journal = "Fuel",

issn = "0016-2361",

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TY - JOUR

T1 - Algorithmic determination of the mechanism through which H2O-dilution affects autoignition dynamics and NO formation in CH4/air mixtures

AU - Tingas, Efstathios Al

AU - Kyritsis, Dimitrios

AU - Goussis, Dimitris A.

PY - 2016/11/1

Y1 - 2016/11/1

N2 - The Computational Singular Perturbation (CSP) algorithm is employed in order to determine how H2O-dilution influences ignition delay and chemical paths that generate NO during isochoric homogenous lean CH4/air autoignition. Regarding the ignition delay, it is shown that H2O-dilution enhances reactivity, mainly due to the increased OH production throughout the explosive stage via reaction H2O2(+H2O)→OH+OH(+H2O). With regard to NO generation, the relative importance of thermal and chemical effects are examined and it is concluded that both are important. The thermal effects result in a lower temperature at the end of the explosive stage, while the most notable chemical effect is the lower level of O after this stage, mainly due to the effect of H2O-dilution on the equilibrium of the reaction O+H2O↔OH+OH. The depletion of O, together with the thermal effect, causes a substantial decrease in final NO generation.

AB - The Computational Singular Perturbation (CSP) algorithm is employed in order to determine how H2O-dilution influences ignition delay and chemical paths that generate NO during isochoric homogenous lean CH4/air autoignition. Regarding the ignition delay, it is shown that H2O-dilution enhances reactivity, mainly due to the increased OH production throughout the explosive stage via reaction H2O2(+H2O)→OH+OH(+H2O). With regard to NO generation, the relative importance of thermal and chemical effects are examined and it is concluded that both are important. The thermal effects result in a lower temperature at the end of the explosive stage, while the most notable chemical effect is the lower level of O after this stage, mainly due to the effect of H2O-dilution on the equilibrium of the reaction O+H2O↔OH+OH. The depletion of O, together with the thermal effect, causes a substantial decrease in final NO generation.

KW - Autoignition

KW - CSP

KW - Methane

KW - NO

KW - Water dilution

UR - https://www.scopus.com/pages/publications/84975318464

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DO - 10.1016/j.fuel.2016.06.057

M3 - Article

AN - SCOPUS:84975318464

SN - 0016-2361

VL - 183

SP - 90

EP - 98

JO - Fuel

JF - Fuel

ER -

Algorithmic determination of the mechanism through which H₂O-dilution affects autoignition dynamics and NO formation in CH₄/air mixtures

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Keywords

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