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Ignition characteristics of dual-fuel methane-n-hexane-oxygen-diluent mixtures in a rapid compression machine and a shock tube

He, Yizhuo and Wang, Yingdi and Grégoire, Claire and Niedzielska, Urszula and Mével, Rémy and Shepherd, Joseph E. (2019) Ignition characteristics of dual-fuel methane-n-hexane-oxygen-diluent mixtures in a rapid compression machine and a shock tube. Fuel, 249 . pp. 379-391. ISSN 0016-2361. http://resolver.caltech.edu/CaltechAUTHORS:20190329-083647697

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Abstract

Ignition delay times of methane-n-hexane-oxygen-dulent mixtures were studied experimentally and numerically in a wide temperature range (640–2335 K) using both a rapid compression machine (RCM) and a shock tube (ST). The RCM results demonstrated a two-stage ignition and negative temperature coefficient (NTC) behavior. Increasing n-hexane concentration, pressure and equivalence ratio shortened the ignition delay time. For the ST experiments, the addition of 10% n-hexane (relative to methane) can reduce the ignition delay time dramatically. However, no further reduction effect can be achieved with increasing addition of n-hexane from 10% to 20%. In addition, increasing equivalence ratio reduces the effect of n-hexane addition on ignition delay time. Three detailed chemical mechanisms, CaltechMech, GalwayMech and LLNLMech, were evaluated based on a quantitative error analysis. LLNLMech and CaltechMech demonstrated the best performance in the RCM and ST temperature ranges, respectively. Chemical kinetic analyses showed that the addition of n-hexane to methane provides some chemical pathways not available for methane oxidation which result in the production of active radicals and eventually accelerate the ignition of the methane-oxygen mixtures. The crucial intermediate species for the ignition process are H_2O_2 and H under RCM and ST conditions, respectively.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1016/j.fuel.2019.03.105DOIArticle
ORCID:
AuthorORCID
Shepherd, Joseph E.0000-0003-3181-9310
Additional Information:© 2019 Elsevier. Received 8 January 2019, Revised 18 March 2019, Accepted 19 March 2019, Available online 29 March 2019. Financial support from the Center for Combustion Energy, and 1000 Young Talents program are highly appreciated. CG is grateful to the Conseil Régional du Centre for sponsoring a student fellowship during her stay at Caltech. UN is grateful to Polish-U.S. Fulbright Commission for sponsoring her stay at Caltech as a Visiting Special Student.
Group:GALCIT
Funders:
Funding AgencyGrant Number
Center for Combustion EnergyUNSPECIFIED
1000 Young Talents ProgramUNSPECIFIED
Conseil Régional du CentreUNSPECIFIED
Polish-U.S. Fulbright CommissionUNSPECIFIED
Subject Keywords:Dual-fuel ignition; Methane-n-hexane mixtures; Rapid compression machine; Shock tube; Chemical kinetics modeling
Record Number:CaltechAUTHORS:20190329-083647697
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20190329-083647697
Official Citation:Yizhuo He, Yingdi Wang, Claire Grégoire, Urszula Niedzielska, Remy Mével, Joseph E. Shepherd, Ignition characteristics of dual-fuel methane-n-hexane-oxygen-diluent mixtures in a rapid compression machine and a shock tube, Fuel, Volume 249, 2019, Pages 379-391, ISSN 0016-2361, https://doi.org/10.1016/j.fuel.2019.03.105.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:94285
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:29 Mar 2019 16:07
Last Modified:29 Mar 2019 16:07

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