Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol

Handle URI:
http://hdl.handle.net/10754/625136
Title:
Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol
Authors:
Singh, Eshan ( 0000-0001-8851-4724 ) ; Waqas, Muhammad; Johansson, Bengt; Sarathy, Mani ( 0000-0002-3975-6206 )
Abstract:
The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.
KAUST Department:
King Abdullah University of Science and Technology, , Saudi Arabia
Citation:
Singh E, Waqas M, Johansson B, Sarathy M (2017) Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol. SAE Technical Paper Series. Available: http://dx.doi.org/10.4271/2017-01-0734.
Publisher:
SAE International
Journal:
SAE Technical Paper Series
Conference/Event name:
SAE World Congress Experience, WCX 2017
Issue Date:
28-Mar-2017
DOI:
10.4271/2017-01-0734
Type:
Conference Paper
Additional Links:
https://saemobilus.sae.org/content/2017-01-0734
Appears in Collections:
Conference Papers

Full metadata record

DC FieldValue Language
dc.contributor.authorSingh, Eshanen
dc.contributor.authorWaqas, Muhammaden
dc.contributor.authorJohansson, Bengten
dc.contributor.authorSarathy, Manien
dc.date.accessioned2017-06-22T13:08:36Z-
dc.date.available2017-06-22T13:08:36Z-
dc.date.issued2017-03-28en
dc.identifier.citationSingh E, Waqas M, Johansson B, Sarathy M (2017) Simulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanol. SAE Technical Paper Series. Available: http://dx.doi.org/10.4271/2017-01-0734.en
dc.identifier.doi10.4271/2017-01-0734en
dc.identifier.urihttp://hdl.handle.net/10754/625136-
dc.description.abstractThe blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends. The simulations used the actual engine geometry and estimated intake valve closure conditions to replicate the experimentally measured start of combustion (SOC) for various PRF mixtures. The simulated HCCI heat release profiles were shown to reproduce the experimentally observed trends, specifically on the effectiveness of ethanol as a low temperature chemistry inhibitor at various concentrations. Detailed analysis of simulated heat release profiles and the evolution of important radical intermediates (e.g., OH and HO) were used to show the effect of ethanol blending on controlling reactivity. A strong coupling between the low temperature oxidation reactions of ethanol and those of n-heptane and iso-octane is shown to be responsible for the observed blending effects of ethanol/PRF mixtures.en
dc.publisherSAE Internationalen
dc.relation.urlhttps://saemobilus.sae.org/content/2017-01-0734en
dc.rightsArchived with thanks to SAE Technical Paper Seriesen
dc.titleSimulating HCCI Blending Octane Number of Primary Reference Fuel with Ethanolen
dc.typeConference Paperen
dc.contributor.departmentKing Abdullah University of Science and Technology, , Saudi Arabiaen
dc.identifier.journalSAE Technical Paper Seriesen
dc.conference.date2017-04-04 to 2017-04-06en
dc.conference.nameSAE World Congress Experience, WCX 2017en
dc.conference.locationDetroit, MI, USAen
dc.eprint.versionPublisher's Version/PDFen
kaust.authorSingh, Eshanen
kaust.authorWaqas, Muhammaden
kaust.authorJohansson, Bengten
kaust.authorSarathy, Manien
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