Characterisation of emissions and combustion stability of a port fuelled spark ignition engine

The chemical and physical limits of cycle-to-cycle combustion variability and engine out emissions of a gasoline port fuelled spark ignition engine have been investigated. The experimental investigations were carried out on a V8 engine with port fuel injection and variable intake valve timing. The...

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Main Author: Brown, Nicholas M
Format: Thesis (University of Nottingham only)
Language:English
Published: 2009
Online Access:https://eprints.nottingham.ac.uk/10821/
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author Brown, Nicholas M
author_facet Brown, Nicholas M
author_sort Brown, Nicholas M
building Nottingham Research Data Repository
collection Online Access
description The chemical and physical limits of cycle-to-cycle combustion variability and engine out emissions of a gasoline port fuelled spark ignition engine have been investigated. The experimental investigations were carried out on a V8 engine with port fuel injection and variable intake valve timing. The chemical limits of stable combustion have been shown to be a function of burned gas, fuel and air mixture. The widest limit, gas fuel ratio of <24, burned gas fraction <0.27 and AFR >9 was found at maximum brake torque spark timing. Retarding the spark timing by 10oCA caused a small reduction in the stable area, 20oCA retard reduced the stable combustion area significantly, whereby stable combustion occurred within an area of gas fuel ratio of <19, burned gas fraction <0.2 and AFR >10. Burn rate analysis indicated increased variability in both the flame development and rapid burn period. The increase in variability in the rapid burn period is greater than that associated with the flame development. The variability is magnified from flame development through the rapid burn phase. This finding was consistent for unstable combustion caused by exceeding chemical and physical limits. Engine out emissions were investigated and characterised using engine global state parameters, for example AFR, burned gas fraction, for both stable and unstable combustion conditions. Carbon monoxide and oxides of nitrogen emissions correlations were unaffected by the presence of unstable combustion events whereas hydrocarbon emissions showed a significant increase. The incorporation of these findings were implemented into an engine simulation (Nu-SIM V8) investigating the impact for the New European Drive Cycle condition.
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format Thesis (University of Nottingham only)
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institution University of Nottingham Malaysia Campus
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language English
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publishDate 2009
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spelling nottingham-108212025-02-28T11:09:49Z https://eprints.nottingham.ac.uk/10821/ Characterisation of emissions and combustion stability of a port fuelled spark ignition engine Brown, Nicholas M The chemical and physical limits of cycle-to-cycle combustion variability and engine out emissions of a gasoline port fuelled spark ignition engine have been investigated. The experimental investigations were carried out on a V8 engine with port fuel injection and variable intake valve timing. The chemical limits of stable combustion have been shown to be a function of burned gas, fuel and air mixture. The widest limit, gas fuel ratio of <24, burned gas fraction <0.27 and AFR >9 was found at maximum brake torque spark timing. Retarding the spark timing by 10oCA caused a small reduction in the stable area, 20oCA retard reduced the stable combustion area significantly, whereby stable combustion occurred within an area of gas fuel ratio of <19, burned gas fraction <0.2 and AFR >10. Burn rate analysis indicated increased variability in both the flame development and rapid burn period. The increase in variability in the rapid burn period is greater than that associated with the flame development. The variability is magnified from flame development through the rapid burn phase. This finding was consistent for unstable combustion caused by exceeding chemical and physical limits. Engine out emissions were investigated and characterised using engine global state parameters, for example AFR, burned gas fraction, for both stable and unstable combustion conditions. Carbon monoxide and oxides of nitrogen emissions correlations were unaffected by the presence of unstable combustion events whereas hydrocarbon emissions showed a significant increase. The incorporation of these findings were implemented into an engine simulation (Nu-SIM V8) investigating the impact for the New European Drive Cycle condition. 2009-05-29 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/10821/1/PhD_thesis_NMB.pdf Brown, Nicholas M (2009) Characterisation of emissions and combustion stability of a port fuelled spark ignition engine. PhD thesis, University of Nottingham.
spellingShingle Brown, Nicholas M
Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title_full Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title_fullStr Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title_full_unstemmed Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title_short Characterisation of emissions and combustion stability of a port fuelled spark ignition engine
title_sort characterisation of emissions and combustion stability of a port fuelled spark ignition engine
url https://eprints.nottingham.ac.uk/10821/