Uncertainty quantification of ion chemistry in lean and stoichiometric homogenous mixtures of methane, oxygen, and argon

Handle URI:
http://hdl.handle.net/10754/564192
Title:
Uncertainty quantification of ion chemistry in lean and stoichiometric homogenous mixtures of methane, oxygen, and argon
Authors:
Kim, Daesang; Rizzi, Francesco; Cheng, Kwok Wah; Han, Jie ( 0000-0002-6176-8684 ) ; Bisetti, Fabrizio ( 0000-0001-5162-7805 ) ; Knio, Omar Mohamad
Abstract:
Uncertainty quantification (UQ) methods are implemented to obtain a quantitative characterization of the evolution of electrons and ions during the ignition of methane-oxygen mixtures under lean and stoichiometric conditions. The GRI-Mech 3.0 mechanism is combined with an extensive set of ion chemistry pathways and the forward propagation of uncertainty from model parameters to observables is performed using response surfaces. The UQ analysis considers 22 uncertain rate parameters, which include both chemi-ionization, proton transfer, and electron attachment reactions as well as neutral reactions pertaining to the chemistry of the CH radical. The uncertainty ranges for each rate parameter are discussed. Our results indicate that the uncertainty in the time evolution of the electron number density is due mostly to the chemi-ionization reaction CH+O⇌HCO+ +E- and to the main CH consumption reaction CH+O2 ⇌O+HCO. Similar conclusions hold for the hydronium ion H3O+, since electrons and H3O+ account for more than 99% of the total negative and positive charge density, respectively. Surprisingly, the statistics of the number density of charged species show very little sensitivity to the uncertainty in the rate of the recombination reaction H3O+ +E- →products, until very late in the decay process, when the electron number density has fallen below 20% of its peak value. Finally, uncertainties in the secondary reactions within networks leading to the formation of minor ions (e.g., C2H3O+, HCO+, OH-, and O-) do not play any role in controlling the mean and variance of electrons and H3O+, but do affect the statistics of the minor ions significantly. The observed trends point to the role of key neutral reactions in controlling the mean and variance of the charged species number density in an indirect fashion. Furthermore, total sensitivity indices provide quantitative metrics to focus future efforts aiming at improving the rates of key reactions responsible for the formation of charges during hydrocarbon combustion. © 2015 The Combustion Institute.
KAUST Department:
Clean Combustion Research Center; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Reactive Flow Modeling Laboratory (RFML)
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
Jul-2015
DOI:
10.1016/j.combustflame.2015.03.013
Type:
Article
ISSN:
00102180
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Clean Combustion Research Center; Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorKim, Daesangen
dc.contributor.authorRizzi, Francescoen
dc.contributor.authorCheng, Kwok Wahen
dc.contributor.authorHan, Jieen
dc.contributor.authorBisetti, Fabrizioen
dc.contributor.authorKnio, Omar Mohamaden
dc.date.accessioned2015-08-03T12:35:51Zen
dc.date.available2015-08-03T12:35:51Zen
dc.date.issued2015-07en
dc.identifier.issn00102180en
dc.identifier.doi10.1016/j.combustflame.2015.03.013en
dc.identifier.urihttp://hdl.handle.net/10754/564192en
dc.description.abstractUncertainty quantification (UQ) methods are implemented to obtain a quantitative characterization of the evolution of electrons and ions during the ignition of methane-oxygen mixtures under lean and stoichiometric conditions. The GRI-Mech 3.0 mechanism is combined with an extensive set of ion chemistry pathways and the forward propagation of uncertainty from model parameters to observables is performed using response surfaces. The UQ analysis considers 22 uncertain rate parameters, which include both chemi-ionization, proton transfer, and electron attachment reactions as well as neutral reactions pertaining to the chemistry of the CH radical. The uncertainty ranges for each rate parameter are discussed. Our results indicate that the uncertainty in the time evolution of the electron number density is due mostly to the chemi-ionization reaction CH+O⇌HCO+ +E- and to the main CH consumption reaction CH+O2 ⇌O+HCO. Similar conclusions hold for the hydronium ion H3O+, since electrons and H3O+ account for more than 99% of the total negative and positive charge density, respectively. Surprisingly, the statistics of the number density of charged species show very little sensitivity to the uncertainty in the rate of the recombination reaction H3O+ +E- →products, until very late in the decay process, when the electron number density has fallen below 20% of its peak value. Finally, uncertainties in the secondary reactions within networks leading to the formation of minor ions (e.g., C2H3O+, HCO+, OH-, and O-) do not play any role in controlling the mean and variance of electrons and H3O+, but do affect the statistics of the minor ions significantly. The observed trends point to the role of key neutral reactions in controlling the mean and variance of the charged species number density in an indirect fashion. Furthermore, total sensitivity indices provide quantitative metrics to focus future efforts aiming at improving the rates of key reactions responsible for the formation of charges during hydrocarbon combustion. © 2015 The Combustion Institute.en
dc.publisherElsevier BVen
dc.subjectChemi-ionizationen
dc.subjectElectronsen
dc.subjectIon chemistryen
dc.subjectPolynomial chaosen
dc.subjectSparse-adaptive samplingen
dc.subjectUncertainty quantificationen
dc.titleUncertainty quantification of ion chemistry in lean and stoichiometric homogenous mixtures of methane, oxygen, and argonen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentComputer, Electrical and Mathematical Sciences and Engineering (CEMSE) Divisionen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentReactive Flow Modeling Laboratory (RFML)en
dc.identifier.journalCombustion and Flameen
dc.contributor.institutionDepartment of Mechanical Engineering and Materials Science, Duke University, Durham, NC, United Statesen
dc.contributor.institutionSchool of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singaporeen
kaust.authorKim, Daesangen
kaust.authorBisetti, Fabrizioen
kaust.authorHan, Jieen
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