Gasoline compression ignition (GCI) engines show promise in meeting stringent new
environmental regulations, as they are characterized by high efficiency and low emissions.
Simulations using chemical kinetic models provide an important platform for investigating the
behaviors of the fuels inside these engines. However, because real fuels are complex, simulations
require surrogate mixtures of small numbers of species that can replicate the properties of real
fuels. Accordingly, the development of high fidelity, well-validated kinetic models for surrogates
is critical in order to accurately replicate the combustion chemistry of different fuels under
engine-related conditions.
This work focuses on the development of combustion kinetic models to better understand
gasoline fuel combustion in GCI engines. An updated iso-octane detailed kinetic model was
developed based on new thermodynamic group values and recently evaluated rate coefficients
from literature. The model was validated against a wide range of experimental data and
conditions.
The iso-octane model was further used in 0D simulations for a homogeneous charge
compression ignition (HCCI) engine. The results showed that the low-temperature heat release in
engines increases with engine boosting when the addition of alky radicals to molecular oxygen is
more favored. Ethanol addition was also found to act as a radical sink which inhibits the radical
pool formation and results in lower reactivity.
Although detailed models provide clarification of the combustion chemistry, their high
computational cost impedes their utilization in 3-D engine simulations. Hence, a reduced model
for toluene primary reference fuels was developed and validated against ignition delay time and
flame speed experiments from literature. The model was then used in numerically investigating
the effects of the fuel’s physical properties using hollow-cone and multi-hole injectors in a
partially premixed compression ignition (PPCI) engine. It was concluded that the effects of
physical properties are evident in multi-hole injection cases, which is attributable to the
differences in mixture stratification.
Finally, reduced models for multi-components surrogates for three full-blend fuels (light
naphtha-Haltermann straight-run naphtha and GCI fuels) were developed. The models were
validated against ignition delay time experiments from the literature and tested in 3D engine
simulations.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/628032 |
| Date | 06 1900 |
| Creators | Atef, Nour |
| Contributors | Sarathy, Mani, Physical Science and Engineering (PSE) Division, Johansson, Bengt, Peinemann, Klaus-Viktor, Im, Hong G., Mehl, Marco |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
| Rights | 2019-07-04, At the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation became available to the public after the expiration of the embargo on 2019-07-04. |
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