subject:(Two stage ignition)

1. Rose, Evan Noah. Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions.

Degree: MSs, EMC - Mechanical Engineering, 2019, Case Western Reserve University School of Graduate Studies

URL: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334

► Understanding the spontaneous ignition and burning behavior of liquid fuels is criticalto improving the performance of modern combustion devices. This work examinesthe effects of varying… (more)

Subjects/Keywords: Mechanical Engineering; combustion; autoignition; ignition; droplet; NTC; two-stage ignition; dodecane

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APA (6^th Edition):

Rose, E. N. (2019). Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions. (Masters Thesis). Case Western Reserve University School of Graduate Studies. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334

Chicago Manual of Style (16^th Edition):

Rose, Evan Noah. “Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions.” 2019. Masters Thesis, Case Western Reserve University School of Graduate Studies. Accessed April 14, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334.

MLA Handbook (7^th Edition):

Rose, Evan Noah. “Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions.” 2019. Web. 14 Apr 2021.

Vancouver:

Rose EN. Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions. [Internet] [Masters thesis]. Case Western Reserve University School of Graduate Studies; 2019. [cited 2021 Apr 14]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334.

Council of Science Editors:

Rose EN. Autoignition Dynamics and Combustion of n-Dodecane Dropletsunder Transcritical Conditions. [Masters Thesis]. Case Western Reserve University School of Graduate Studies; 2019. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=case1554288408975334

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)

Subjects/Keywords: Methyl Ester; Autoignition; Methyl Pentanoate; Methyl Valerate; Rapid Compression Machine; Two-Stage Ignition; Negative Temperature Coefficient

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APA (6^th 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 (16^th 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 (7^th 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 (6^th 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 (16^th 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 (7^th 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

University of Illinois – Chicago

4. Fu, Xiao. Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine.

Degree: 2016, University of Illinois – Chicago

URL: http://hdl.handle.net/10027/20168

► The overall objective of this research is to examine strategies for reducing NOx and soot emissions in diesel engine. The thesis has two parts. In… (more)

▼ The overall objective of this research is to examine strategies for reducing NOx and soot emissions in diesel engine. The thesis has two parts. In the first part, the effect of unsaturation or the presence of a double bond in the fuel molecular structure on NOx and soot formation is investigated. Simulations have been performed for partially premixed flames burning n-heptane and 1-heptene fuels in a counterflow configuration and a constant volume diesel combustion vessel to examine the effect of unsaturation at different level of partial premixing and strain rate. A validated detailed kinetic model with 198 species and 4932 reactions has been used in the counterflow flame simulations. Results indicate that the presence of unsaturated bond leads to increased formation of acetylene and propargyl through  scission reactions, resulting in higher prompt NO, PAH and soot in 1-heptene flames than in n-heptane flames. Since these results are obtained in laminar flames, the study is extended to examine the effect of double bond in spray flames at diesel engine conditions. 3-D simulations are performed using CFD code (CONVERGE) to examine the structure and emission characteristics of n-heptane and 1-heptene spray flames in a constant-volume combustion vessel. The directed relation graph methodology is used to develop a reduced mechanism (207 species and 4094 reactions) starting from the detailed mechanism (482 species and 19072 reactions). Results indicate that the combustion under diesel engine conditions is characterized by a double-flame structure with a rich premixed reaction zone (RPZ) near the flame stabilization region and a non-premixed reaction zone (NPZ) further downstream. Most of NOx is formed via thermal NO route in the NPZ, while PAH species are mainly formed in the RPZ. The presence of a double bond results in  scission reactions, leading to higher temperature and consequently higher NO in 1-heptene flame than that in n-heptane flame. It also leads to a significantly higher PAH species, implying increased soot emission in 1-heptene flame than that in n-heptane flame. Reaction path analysis indicated that this is due to significantly higher amounts of 1,3-butadiene and allene formed from  scission reactions due to the presence of double bond. In the second part of this research, a dual-fuel strategy for reducing emissions in a diesel engine has been examined. N-heptane and methane have been used as surrogates for diesel (pilot fuel) and natural gas (main fuel), respectively. The physical and chemical processes of dual-fuel combustion are simulated using CONVERGE and a reduced reaction mechanism (42 species, 168 reactions). The mechanism is validated against the experimental data for ignition and flame speed at engine relevant conditions. In engine simulations, methane is premixed with air during the intake, and then ignited by the n-heptane pilot injection. The heat release for the single-fuel case involves a hybrid combustion mode, characterized by rich premixed combustion and diffusion combustion,… Advisors/Committee Members: Aggarwal, Suresh K. (advisor), Brezinsky, Kenneth (committee member), Mashayek, Farzad (committee member), Som, Sibendu (committee member), Senecal, Peter K. (committee member).

Subjects/Keywords: Fuel unsaturation; NOx and PAH emissions; counterflow partially premixed flame; n-heptane; 1-heptene; spray combustion; two stage ignition; dual fuel; diesel engine; NTC phenomenon

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APA (6^th Edition):

Fu, X. (2016). Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/20168

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Fu, Xiao. “Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine.” 2016. Thesis, University of Illinois – Chicago. Accessed April 14, 2021. http://hdl.handle.net/10027/20168.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Fu, Xiao. “Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine.” 2016. Web. 14 Apr 2021.

Vancouver:

Fu X. Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine. [Internet] [Thesis]. University of Illinois – Chicago; 2016. [cited 2021 Apr 14]. Available from: http://hdl.handle.net/10027/20168.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Fu X. Partially Premixed Combustion in Counterflow Flame and Dual Fuel Compression Ignition Engine. [Thesis]. University of Illinois – Chicago; 2016. Available from: http://hdl.handle.net/10027/20168

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

5. Bittle, Joshua. Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy.

Degree: MS, Mechanical Engineering, 2011, Texas A&M University

URL: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8945

► Internal combustion engines have dealt with increasingly restricted emissions requirements. After-treatment devices are successful in bringing emissions into compliance, but in-cylinder combustion control can reduce… (more)

▼ Internal combustion engines have dealt with increasingly restricted emissions requirements. After-treatment devices are successful in bringing emissions into compliance, but in-cylinder combustion control can reduce their burden by reducing engine out emissions. For example, oxides of nitrogen (NOx) are diesel combustion exhaust species that are notoriously difficult to remove by after-treatment. In-cylinder conditions can be controlled for low levels of NOx, but this produces high levels of soot potentially leading to increased particulate matter (PM). The simultaneous reduction of NOx and PM can be realized through a combustion process known as low temperature combustion (LTC). In this study, the typical definition of LTC as the defeat of the inverse relationship between soot and NOx is not applicable as a return to the soot-NOx tradeoff is observed with increasing exhaust gas recirculation (EGR). It is postulated that this effect is the result of an increase in the hot ignition equivalence ratio, moving the combustion event into a slightly higher soot formation region. This is important because a simple emissions based definition of LTC is no longer helpful. In this study, the manifestation of LTC in the calculated heat release profile is investigated. The conditions classified as LTC undergo a two-stage ignition process. Two-stage ignition is characterized by an initial cool-flame reaction followed by typical hot ignition. In traditional combustion conditions, the ignition is fast enough that a cool-flame is not observed. By controlling initial conditions (pressure, temperature, and composition), the creation and duration of the cool-flame event is predictable. Further, the effect that injection timing and the exhaust gas recirculation level have on the controlling factors of the cool-flame reaction is well correlated to the duration of the cool-flame event. These two results allow the postulation that the presence of a sufficiently long cool-flame reaction indicates a combustion event that can be classified as low temperature combustion. A potential method for identifying low temperature combustion events using only the rate of heat release profile is theorized. This study employed high levels of EGR and late injection timing to realize the LTC mode of ordinary petroleum diesel fuel. Under these conditions, and based on a 90 percent reduction in nitric oxide and no increase in smoke output relative to the chosen baseline condition, a two part criteria is developed that identifies the LTC classified conditions. The criteria are as follow: the combustion event of conventional petroleum diesel fuel must show a two-stage ignition process; the first stage (cool-flame reaction) must consume at least 2 percent of the normalized fuel energy before the hot ignition commences. Advisors/Committee Members: Jacobs, Timothy (advisor), Caton, Jerald (committee member), Karpetis, Adonios (committee member).

Subjects/Keywords: Two-stage Ignition; Low Temperature Combustion; Diesel; NOx; Cool-flame; diagnostic tool

…27 3. INVESTIGATION OF THE FUNDAMENTAL MECHANISMS THAT CREATE A TWO-STAGE IGNITION EVENT… …44 viii Page 4. TWO-STAGE IGNITION BEHAVIOR CHARACTERISTICS AS A LOW TEMPERATURE… …state where a hot ignition event takes place [14]. Two-stage ignition occurs when… …two-stage ignition occurs. 1.2.2. Low Temperature Combustion Attainment Both soot and NOx… …auto-ignition. The discussion by Fish et al. combines these two effects. By controlling the…

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Bittle, J. (2011). Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy. (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8945

Chicago Manual of Style (16^th Edition):

Bittle, Joshua. “Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy.” 2011. Masters Thesis, Texas A&M University. Accessed April 14, 2021. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8945.

MLA Handbook (7^th Edition):

Bittle, Joshua. “Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy.” 2011. Web. 14 Apr 2021.

Vancouver:

Bittle J. Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy. [Internet] [Masters thesis]. Texas A&M University; 2011. [cited 2021 Apr 14]. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8945.

Council of Science Editors:

Bittle J. Two-stage Ignition as an Indicator of Low Temperature Combustion in a Late Injection Pre-mixed Compression Ignition Control Strategy. [Masters Thesis]. Texas A&M University; 2011. Available from: http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8945

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