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Combustion characteristics of some alternative fuels in ICE: : a detailed numerical study

Hu, Siyuan LU (2017)
Abstract
Two major fuels commonly used in compression ignition (CI) and spark ignition (SI) engines
are diesel and gasoline. The reserve of diesel and gasoline is limited, however the combustion of
these fuels giving rise to air pollution. This calls for the search for alternative fuels, preferably
renewable fuels, and the development of more efficient and clean combustion technologies for
internal combustion engines. The thesis deals with direct numerical simulation (DNS) of the
combustion process in various alternative fuels under conditions relevant to SI engines and CI
engines. The fuels considered are methane, hydrogen, and methanol. The internal structure
and the propagation speed of methane/air flames and of... (More)
Two major fuels commonly used in compression ignition (CI) and spark ignition (SI) engines
are diesel and gasoline. The reserve of diesel and gasoline is limited, however the combustion of
these fuels giving rise to air pollution. This calls for the search for alternative fuels, preferably
renewable fuels, and the development of more efficient and clean combustion technologies for
internal combustion engines. The thesis deals with direct numerical simulation (DNS) of the
combustion process in various alternative fuels under conditions relevant to SI engines and CI
engines. The fuels considered are methane, hydrogen, and methanol. The internal structure
and the propagation speed of methane/air flames and of hydrogen-enriched methane/air flames
are studied for a range of equivalence ratio and pressure conditions. The methods of flame-
cone-angle and flame-area for determining the laminar flame speed of methane/air flames in
the Bunsen burner configuration are evaluated using DNS. For hydrogen-enriched methane/air
flames, the correlation between the laminar flame speed and the hydrogen enrichment ratio is
determined for a range of equivalence ratios, efforts being made to the mechanisms involved
in the peak laminar flame speed shifting towards fuel-rich mixtures. For the studies on meth-
anol combustion the focus was on the combustion characteristics of methanol/n-heptane/air
mixtures under dual-fuel CI engine relevant conditions. It was found that methanol combus-
tion under dual-fuel conditions can occur in multiple modes: auto-ignition, premixed flame
propagation and diffusion flame, depending upon the injection strategies and the ambient pres-
sure and the ambient temperature conditions. The effects of different operating conditions on
the modes of methanol/n-heptane dual-fuel combustion were identified. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Lovås, Terese, NTNU, Norway
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Combustion, duel fuel, methane, hydrogen, nheptane, methanol, DNS, simulation, openFoam, mixture-averaged, RCCI, ignition wave
edition
2017
pages
164 pages
publisher
Department of Energy Sciences, Lund University
defense location
Aula Genetikhuset, Sölvegatan 29, Lund University.
defense date
2017-10-02 10:15:00
ISBN
978-91-629-0220-9
978-91-629-0219-3
language
English
LU publication?
yes
id
73b902e4-1c54-49f7-9a5c-68f78498b237
date added to LUP
2017-09-07 13:17:08
date last changed
2022-02-25 14:21:04
@phdthesis{73b902e4-1c54-49f7-9a5c-68f78498b237,
  abstract     = {{Two major fuels commonly used in compression ignition (CI) and spark ignition (SI) engines<br/>are diesel and gasoline. The reserve of diesel and gasoline is limited, however the combustion of<br/>these fuels giving rise to air pollution. This calls for the search for alternative fuels, preferably<br/>renewable fuels, and the development of more efficient and clean combustion technologies for<br/>internal combustion engines. The thesis deals with direct numerical simulation (DNS) of the<br/>combustion process in various alternative fuels under conditions relevant to SI engines and CI<br/>engines. The fuels considered are methane, hydrogen, and methanol. The internal structure<br/>and the propagation speed of methane/air flames and of hydrogen-enriched methane/air flames<br/>are studied for a range of equivalence ratio and pressure conditions. The methods of flame-<br/>cone-angle and flame-area for determining the laminar flame speed of methane/air flames in<br/>the Bunsen burner configuration are evaluated using DNS. For hydrogen-enriched methane/air<br/>flames, the correlation between the laminar flame speed and the hydrogen enrichment ratio is<br/>determined for a range of equivalence ratios, efforts being made to the mechanisms involved<br/>in the peak laminar flame speed shifting towards fuel-rich mixtures. For the studies on meth-<br/>anol combustion the focus was on the combustion characteristics of methanol/n-heptane/air<br/>mixtures under dual-fuel CI engine relevant conditions. It was found that methanol combus-<br/>tion under dual-fuel conditions can occur in multiple modes: auto-ignition, premixed flame<br/>propagation and diffusion flame, depending upon the injection strategies and the ambient pres-<br/>sure and the ambient temperature conditions. The effects of different operating conditions on<br/>the modes of methanol/n-heptane dual-fuel combustion were identified.}},
  author       = {{Hu, Siyuan}},
  isbn         = {{978-91-629-0220-9}},
  keywords     = {{Combustion; duel fuel; methane; hydrogen; nheptane; methanol; DNS; simulation; openFoam; mixture-averaged; RCCI; ignition wave}},
  language     = {{eng}},
  month        = {{09}},
  publisher    = {{Department of Energy Sciences, Lund University}},
  school       = {{Lund University}},
  title        = {{Combustion characteristics of some alternative fuels in ICE: : a detailed numerical study}},
  year         = {{2017}},
}