NSYSU
1.
Wang, Hsin-Yao.
Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate.
Degree: Master, Mechanical and Electro-Mechanical Engineering, 2018, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0109118-181737 
► Toward the goals of understanding the chemistry involving in pyrolysis and oxidation. Three chemical kinetic mechanisms have been developed and refined to better represent these…
(more)
▼ Toward the goals of understanding the chemistry involving in pyrolysis and oxidation. Three chemical kinetic mechanisms have been developed and refined to better represent these characteristics.
The first mechanism newly refined describes the detailed pyrolysis of acetylene and ethylene with 456 species and 2045 reactions that are proposed to predict experimentally measured formation of polycyclic aromatic hydrocarbons (PAHs) at different temperatures (1073-1323 K) in a tubular flow reactor at atmospheric pressure. These PAH species, which are up to 4 rings, have been classified by the United States Environmental Protection Agency (USEPA) as the carcinogenic and mutagenic compounds to human health. The chemical formulas include naphthalene (C10H8), acenaphthylene (C12H8), fluorene (C13H10), phenanthrene (C14H10), anthracene (C14H10), fluoranthene (C16H10) and pyrene (C16H10). In addition, rate of production analysis is applied to interpret the correlation between C2 unsaturated hydrocarbons and PAH compounds involving in the pyrolysis of acetylene (C2H2) and ethylene (C2H4). In addition, this newly proposed C2H2-C2H4-PAH mechanism can be used as a base model to constitute kinetic mechanisms for large hydrocarbon fuel oxidation.
The second mechanism is a newly derived skeletal model for propane-PAH oxidation. The study is driven by the need to develop a skeletal mechanism to predict the mass-spectrometrically measured hydrocarbons and aromatic hydrocarbons in a nonpremixed coflowing propane/air flame. Via a mechanism reduction process, a skeletal propane-PAH mechanism (76 species and 324 reactions) is generated with reasonable accuracy. Without empirical adjustment of rate constants in elementary reactions, the propane-PAH mechanism is validated against experimental ignition delay times in a rapid compression machine and species profiles in opposed flow diffusion flames. For the first time, the propane-PAH mechanism incorporated into a 2-D CFD model of coflowing flame is able to predict the experimentally measured centerline mole fractions of 22 hydrocarbons and aromatic compounds up to C12 species. Furthermore, reaction pathway analysis is produced to disclose the correlation between the decomposition of propane and the formation of the measured compounds.
The third study is to refine an existing detailed mechanism of a medium-sized biodiesel surrogate (methyl octanoate/ethanol) in terms of the prediction for low-
temperature combustion (T < 1000 K). Three primary unimolecular reaction pathways of methyl octanoate peroxy radicals, including (1) dissociation, (2) isomerization and (3) hydroperoxy elimination, and two primary unimolecular reaction pathways of hydroperoxy methyl octanoate radicals, including (4) β-scission and (5) intramolecular substitution are investigated and updated with the newly estimated rate constants. The refined mechanism is validated against the experimentally measured oxidation rate of methyl octanoate and ethanol with methyl octanoate/ethanol 90/10 mol % fuel mixture in a jet-stirred…
Advisors/Committee Members: Sheng-Lun Lin (chair), C. H. Chiang (chair), S.-Y. Hsu (chair), Kuang C. Lin (committee member).
Subjects/Keywords: Polycyclic Aromatic Hydrocarbon (PAH); Ethylene; Pyrolysis; Acetylene; Kinetic mechanism; Biodiesel surrogate; Propane oxidation; CFD; Negative-temperature-coefficient
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APA (6th Edition):
Wang, H. (2018). Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0109118-181737
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Hsin-Yao. “Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate.” 2018. Thesis, NSYSU. Accessed April 14, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0109118-181737.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Hsin-Yao. “Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate.” 2018. Web. 14 Apr 2021.
Vancouver:
Wang H. Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate. [Internet] [Thesis]. NSYSU; 2018. [cited 2021 Apr 14].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0109118-181737.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang H. Refinements of chemical kinetic mechanisms for C2-C3 hydrocarbon fuels and a C9 biodiesel surrogate. [Thesis]. NSYSU; 2018. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0109118-181737
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Connecticut
2.
Bunnell, Justin.
Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine.
Degree: MS, Mechanical Engineering, 2015, University of Connecticut
URL: https://opencommons.uconn.edu/gs_theses/770
► Autoignition experiments were performed in a rapid compression machine for methyl pentanoate. Autoignition conditions ranged from 682 K to 1048 K for pressures of…
(more)
▼ Autoignition experiments were performed in a rapid compression machine for methyl pentanoate. Autoignition conditions ranged from 682 K to 1048 K for pressures of 15 bar and 30 bar and equivalence ratios of 0.25, 0.50, and 1.0. The composition of the oxidizer was altered by changing the amount of argon and molecular nitrogen in the mixtures. Over the conditions studied, it was found that the reactivity of the mixture increases with increasing compressed pressure and equivalence ratio.
Negative temperature coefficient behavior was observed for compressed temperatures ranging from 716 K to 799 K under a compressed pressure of 30 bar and an equivalence ratio of 1.0. Experimental data was compared to ignition delay data for methyl butanoate and methyl propanoate. For all available data, methyl pentanoate was the most reactive fuel followed by methyl butanoate and methyl propanoate. Experimental data was extrapolated and indicated that methyl butanoate and methyl pentanoate might have the same reactivity at 1030 K and 975 K for compressed pressures of 30 bar and equivalence ratios of φ = 0.25 and φ = 0.50, respectively. Experimental data for methyl pentanoate was further simulated using a literature chemical kinetic mechanism. Overall there was poor agreement between experimental data and simulations for
negative temperature coefficient behavior and ignition delays. Only simulations for compressed temperatures below 700 K seem to agree well with experimental data.
Advisors/Committee Members: Dr. Michael Renfro, Dr. Baki Cetegen, Dr. Chih-Jen Sung.
Subjects/Keywords: Methyl Ester; Autoignition; Methyl Pentanoate; Methyl Valerate; Rapid Compression Machine; Two-Stage Ignition; Negative Temperature Coefficient
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APA ·
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MLA ·
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APA (6th Edition):
Bunnell, J. (2015). Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine. (Masters Thesis). University of Connecticut. Retrieved from https://opencommons.uconn.edu/gs_theses/770
Chicago Manual of Style (16th Edition):
Bunnell, Justin. “Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine.” 2015. Masters Thesis, University of Connecticut. Accessed April 14, 2021.
https://opencommons.uconn.edu/gs_theses/770.
MLA Handbook (7th Edition):
Bunnell, Justin. “Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine.” 2015. Web. 14 Apr 2021.
Vancouver:
Bunnell J. Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine. [Internet] [Masters thesis]. University of Connecticut; 2015. [cited 2021 Apr 14].
Available from: https://opencommons.uconn.edu/gs_theses/770.
Council of Science Editors:
Bunnell J. Autoignition of Methyl Pentanoate at Low to Intermediate Temperatures and Elevated Pressures in a Rapid Compression Machine. [Masters Thesis]. University of Connecticut; 2015. Available from: https://opencommons.uconn.edu/gs_theses/770
University of New South Wales
3.
Krisman, Alexander.
Direct numerical simulation of diesel-relevant combustion.
Degree: Mechanical & Manufacturing Engineering, 2016, University of New South Wales
URL: http://handle.unsw.edu.au/1959.4/55498
;
https://unsworks.unsw.edu.au/fapi/datastream/unsworks:37862/SOURCE02?view=true
► Diesel combustion is a major contributor to global energy production. However, despite major improvements to diesel engine design, substantial gaps exist in the fundamental description…
(more)
▼ Diesel combustion is a major contributor to global energy production. However, despite major improvements to diesel engine design, substantial gaps exist in the fundamental description of the in-cylinder combustion process. This impedes the development of simple, predictive models which are necessary for designing improved combustion devices. In particular, only an under-resolved description of ignition and lifted flame stabilisation exists, due to physical limitations of experimental measurements. Ignition and flame stabilisation govern the formation of pollutants and combustion efficiency, and so a refined understanding is required. In this thesis, direct numerical simulation (DNS) techniques are applied to idealised configurations that represent facets of diesel combustion. A particular focus is applied to representing the correct thermochemical conditions which result in multi-stage autoignition and a
negative temperature coefficient (NTC) regime of ignition delay times. The results were broadly consistent with prior experimental studies, but the well-resolved information also revealed details of several novel combustion features that have not been previously reported. Simulations of lifted laminar flames at NTC conditions with detailed dimethyl ether chemistry observed that edge flame or hybrid edge flame/autoignition structures can exist even at diesel-relevant autoignitive conditions, which raises the possibility that edge flame propagation or a combination of edge flame propagation and autoignition are responsible for diesel flame stabilisation. The ignition of a two-dimensional mixing layer at NTC conditions in isotropic turbulence with detailed dimethyl ether chemistry was conducted. A complex ignition process was observed in which two-stage autoignition, cool flames, and hybrid edge flame/autoignition structures contributed to the overall ignition process. In particular, it was observed that the cool flame influenced the timing and location of the high
temperature ignition. A three-dimensional ignition at NTC conditions with global heptane chemistry was conducted. The results were consistent with the two-dimensional mixing layer results. The results also emphasised the importance of mixing rates in determining the location and timing of high
temperature ignition. Overall, this thesis complements prior experimental results, identifies novel combustion features and highlights the substantial modelling challenge presented by diesel combustion.
Advisors/Committee Members: Hawkes, Evatt, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW, Kook, Sanghoon, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW.
Subjects/Keywords: Negative temperature coefficient; Direct numerical simulation; Diesel-relevant combustion; Triple flame; Two-stage ignition; Polybrachial flame; Tribrachial flame; Ignition; Cool flame; Edge flame
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APA ·
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MLA ·
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APA (6th Edition):
Krisman, A. (2016). Direct numerical simulation of diesel-relevant combustion. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/55498 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:37862/SOURCE02?view=true
Chicago Manual of Style (16th Edition):
Krisman, Alexander. “Direct numerical simulation of diesel-relevant combustion.” 2016. Doctoral Dissertation, University of New South Wales. Accessed April 14, 2021.
http://handle.unsw.edu.au/1959.4/55498 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:37862/SOURCE02?view=true.
MLA Handbook (7th Edition):
Krisman, Alexander. “Direct numerical simulation of diesel-relevant combustion.” 2016. Web. 14 Apr 2021.
Vancouver:
Krisman A. Direct numerical simulation of diesel-relevant combustion. [Internet] [Doctoral dissertation]. University of New South Wales; 2016. [cited 2021 Apr 14].
Available from: http://handle.unsw.edu.au/1959.4/55498 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:37862/SOURCE02?view=true.
Council of Science Editors:
Krisman A. Direct numerical simulation of diesel-relevant combustion. [Doctoral Dissertation]. University of New South Wales; 2016. Available from: http://handle.unsw.edu.au/1959.4/55498 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:37862/SOURCE02?view=true
4.
Chomier, Mickael Thierry.
Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine.
Degree: MSin Engineering, Mechanical Engineering, 2013, University of Akron
URL: http://rave.ohiolink.edu/etdc/view?acc_num=akron1374666527
► The objective of this thesis is to understand the influence of the non-ideal effects in Rapid Compression Machines (RCM), namely the vortex roll-up and mass…
(more)
▼ The objective of this thesis is to understand the
influence of the non-ideal effects in Rapid Compression Machines
(RCM), namely the vortex roll-up and mass flow into the crevice, on
autoignition. The effect of the vortex roll-up is studied
computationally using CFD simulations of autoignition in a RCM.
Whereas, the effect of the crevice mass flow is investigated
experimentally by studying isooctane autoignition. Over the last
two decades, experimental data of the nature of species evolution
profiles and ignition delays from RCMs has been used to develop and
validate chemical kinetic mechanisms at low-to-intermediate
temperatures and elevated pressures. A significant portion of this
overall dataset is from RCMs that had not employed a creviced
piston to contain the roll-up vortex. The detrimental influence of
the roll-up vortex and the thermokinetic interactions due to the
resulting
temperature non-homogeneity during the
negative
temperature coefficient (ntc) regime have been documented in the
literature. However, the adequacy of the homogeneous modeling of
RCMs without creviced pistons during reactive conditions has not
been investigated. In this work, computational fluid dynamics
simulations of an RCM without a creviced piston are conducted for
autoignition of n-heptane over the entire ntc regime over a range
of compressed pressures from 5 to 18 bar. The results from the CFD
simulations highlight the non-homogeneity of autoignition and
reveal significant quantitative discrepancy in comparison to
homogeneous modeling, particularly for the hot ignition delay in
the ntc regime. Specifically, the roll-up vortex induced
temperature non-homogeneity leads to diminution of the ntc
behavior. The experimental data from RCMs without creviced piston
needs to be taken with caution for quantitative validation and
refinement of kinetic mechanism, particularly at conditions when
ntc behavior is highly pronounced.Rapid Compression Machines (RCMs)
often employ creviced pistons to suppress the formation of the
roll-up vortex. However, the use of a creviced piston promotes mass
flow into the crevice when heat release takes place in the main
combustion chamber. This multi-dimensional effect is not accounted
for in the prevalent volumetric expansion approach for modeling
RCMs. The method of crevice containment, on the other hand, avoids
post-compression mass flow into the crevice. In order to assess the
effect of the crevice mass flow on ignition in a RCM, experiments
were conducted for autoignition of isooctane in a RCM with creviced
piston in the
temperature range of 680-940 K and at compressed
pressures of ¿ 15.5 and 20.5 bar in two ways. In one
situation, post-compression mass flow to the crevice is avoided by
crevice containment and in other it is allowed. Experiments show
that the crevice mass flow can lead to significantly longer
ignition delays. Experimental data from both scenarios is modeled
using adiabatic volumetric expansion approach and an available
kinetic mechanism. The simulated results show less pronounced
effect…
Advisors/Committee Members: Mittal, Gaurav (Advisor).
Subjects/Keywords: Mechanical Engineering; rapid compression machine, RCM , ignition, non ideal
effect, roll-up, vortex, mass flow, crevice piston, flat piston,
crevice containment, iso-octane, n-heptane, NTC, negative
temperature coefficient
…the lower end of the negative temperature coefficient
(ntc) range (In the ntc… …iso-octane mixtures a
temperature-leveling effect, ascribed to the negative temperature… …coefficient of
reaction rate was observed.
In 2001, the temperature field in a RCM was imaged by… …compressed temperature
range exhibiting a negative temperature dependence of the overall reaction… …temperature conditions….21
ix
LIST OF FIGURES
Figures
Page
1.1
Schematic of the RCM used in…
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chomier, M. T. (2013). Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine. (Masters Thesis). University of Akron. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=akron1374666527
Chicago Manual of Style (16th Edition):
Chomier, Mickael Thierry. “Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine.” 2013. Masters Thesis, University of Akron. Accessed April 14, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=akron1374666527.
MLA Handbook (7th Edition):
Chomier, Mickael Thierry. “Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine.” 2013. Web. 14 Apr 2021.
Vancouver:
Chomier MT. Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine. [Internet] [Masters thesis]. University of Akron; 2013. [cited 2021 Apr 14].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1374666527.
Council of Science Editors:
Chomier MT. Effect of Vortex Roll-up and Crevice Mass Flow on Ignition
in a Rapid Compression Machine. [Masters Thesis]. University of Akron; 2013. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=akron1374666527
Open Access Theses and Dissertations
