{"id":{"repo_id":"uic","oai_identifier":"oai:figshare.com:article/31451104"},"canonical_url":"https://search.dev.ndltd.org/etd/uic/oai:figshare.com:article/31451104","repository":{"repo_id":"uic","name":"University of Illinois - Chicago","base_url":"https://api.figshare.com/v2/oai"},"display":{"title":"A Fuel Surrogate Approach to Model Combustion Chemistry in Specialty Jet Fuels","abstract":"Single pulse shock tube experiments were conducted to study the oxidation and pyrolysis speciation of six cetane number (CN) specialty fuels - CN30, CN35, CN40, CN45, CN50, and CN55, and F-24, a multi-component jet fuel. The experiments were performed at 50 atm nominal pressure, 4.2 ms nominal reaction times over a temperature range of 900–1800 K, and an equivalence ratio of approximately 1.0. Gas chromatography was used to qualitatively and quantitatively analyze the post shock gases. The relationship between the formation of key intermediate species and the chemically controlled combustion propensity as reflected by the cetane number of each fuel was examined. The oxidation and pyrolysis speciation data were first modeled using a surrogate-based mechanism from the CRECK Modelling Group and chemical-functional group based optimized surrogates (CFGO), showing less than satisfactory agreement. Adjusting the aromatic content of the surrogates led to overall improvements in the oxidation modeling. In the case of pyrolysis, the CFGO surrogate model showed satisfactory agreement in capturing the chemistry of most species except two important pyrolysis intermediates – ethylene and acetylene. Chemical kinetic analyses were performed to identify the important reactions which affect the chemistry of these species; however, the rate parameters of critical reactions were found to be unsuitable for simulating the present high-pressure studies. To address this unsuitability, a theory-based fall-off analysis for three reactions representing the decomposition of ethylene and subsequent formation of acetylene was performed, and these are included in an updated version of the CRECK mechanism. This update resolves discrepancies between the experimental results and simulations for ethylene and acetylene. Rate of production, sensitivity and reaction path analyses using the updated surrogate model showed that the primary reactions responsible for driving the combustion chemistry were largely influenced by the chemical functional groups present in the complex multi-component fuels. In addition to highlighting the effectiveness of the fuel-surrogate approach, where surrogates representing the chemical functional group composition of the parent fuel serve as a valuable tool for predicting the combustion chemistry of novel fuels, the study also underscores the value of updating the rate parameters of specific reactions to improve modeling.","abstract_html":"Single pulse shock tube experiments were conducted to study the oxidation and pyrolysis speciation of six cetane number (CN) specialty fuels - CN30, CN35, CN40, CN45, CN50, and CN55, and F-24, a multi-component jet fuel. The experiments were performed at 50 atm nominal pressure, 4.2 ms nominal reaction times over a temperature range of 900–1800 K, and an equivalence ratio of approximately 1.0. Gas chromatography was used to qualitatively and quantitatively analyze the post shock gases. The relationship between the formation of key intermediate species and the chemically controlled combustion propensity as reflected by the cetane number of each fuel was examined. The oxidation and pyrolysis speciation data were first modeled using a surrogate-based mechanism from the CRECK Modelling Group and chemical-functional group based optimized surrogates (CFGO), showing less than satisfactory agreement. Adjusting the aromatic content of the surrogates led to overall improvements in the oxidation modeling. In the case of pyrolysis, the CFGO surrogate model showed satisfactory agreement in capturing the chemistry of most species except two important pyrolysis intermediates – ethylene and acetylene. Chemical kinetic analyses were performed to identify the important reactions which affect the chemistry of these species; however, the rate parameters of critical reactions were found to be unsuitable for simulating the present high-pressure studies. To address this unsuitability, a theory-based fall-off analysis for three reactions representing the decomposition of ethylene and subsequent formation of acetylene was performed, and these are included in an updated version of the CRECK mechanism. This update resolves discrepancies between the experimental results and simulations for ethylene and acetylene. Rate of production, sensitivity and reaction path analyses using the updated surrogate model showed that the primary reactions responsible for driving the combustion chemistry were largely influenced by the chemical functional groups present in the complex multi-component fuels. In addition to highlighting the effectiveness of the fuel-surrogate approach, where surrogates representing the chemical functional group composition of the parent fuel serve as a valuable tool for predicting the combustion chemistry of novel fuels, the study also underscores the value of updating the rate parameters of specific reactions to improve modeling.","abstract_has_math":false,"creators":["Mohammed Abdulrahman (23291353)"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-12-01T00:00:00Z","date_published":"2025-12-01T00:00:00Z","updated_at":"2026-07-27T21:34:21Z","subjects":["Engineering, Mechanical","Combustion","Chemical Kinetics"],"languages":[],"rights":["In Copyright"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.25417/uic.31451104.v1","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Mohammed Abdulrahman (23291353)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-12-01T00:00:00Z"]},{"key":"dc:relation","label":"Dc Relation","values":["https://figshare.com/articles/thesis/A_Fuel_Surrogate_Approach_to_Model_Combustion_Chemistry_in_Specialty_Jet_Fuels/31451104"]},{"key":"dc:type","label":"Dc Type","values":["Text","Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Mechanical","Combustion","Chemical Kinetics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.25417/uic.31451104.v1"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Single pulse shock tube experiments were conducted to study the oxidation and pyrolysis speciation of six cetane number (CN) specialty fuels - CN30, CN35, CN40, CN45, CN50, and CN55, and F-24, a multi-component jet fuel. The experiments were performed at 50 atm nominal pressure, 4.2 ms nominal reaction times over a temperature range of 900–1800 K, and an equivalence ratio of approximately 1.0. Gas chromatography was used to qualitatively and quantitatively analyze the post shock gases. The relationship between the formation of key intermediate species and the chemically controlled combustion propensity as reflected by the cetane number of each fuel was examined. The oxidation and pyrolysis speciation data were first modeled using a surrogate-based mechanism from the CRECK Modelling Group and chemical-functional group based optimized surrogates (CFGO), showing less than satisfactory agreement. Adjusting the aromatic content of the surrogates led to overall improvements in the oxidation modeling. In the case of pyrolysis, the CFGO surrogate model showed satisfactory agreement in capturing the chemistry of most species except two important pyrolysis intermediates – ethylene and acetylene. Chemical kinetic analyses were performed to identify the important reactions which affect the chemistry of these species; however, the rate parameters of critical reactions were found to be unsuitable for simulating the present high-pressure studies. To address this unsuitability, a theory-based fall-off analysis for three reactions representing the decomposition of ethylene and subsequent formation of acetylene was performed, and these are included in an updated version of the CRECK mechanism. This update resolves discrepancies between the experimental results and simulations for ethylene and acetylene. Rate of production, sensitivity and reaction path analyses using the updated surrogate model showed that the primary reactions responsible for driving the combustion chemistry were largely influenced by the chemical functional groups present in the complex multi-component fuels. In addition to highlighting the effectiveness of the fuel-surrogate approach, where surrogates representing the chemical functional group composition of the parent fuel serve as a valuable tool for predicting the combustion chemistry of novel fuels, the study also underscores the value of updating the rate parameters of specific reactions to improve modeling."]},{"key":"dc:title","label":"Title","values":["A Fuel Surrogate Approach to Model Combustion Chemistry in Specialty Jet Fuels"]}]}],"canonical_facts":{"dc:creator":["Mohammed Abdulrahman (23291353)"],"dc:date":["2025-12-01T00:00:00Z"],"dc:description":["Single pulse shock tube experiments were conducted to study the oxidation and pyrolysis speciation of six cetane number (CN) specialty fuels - CN30, CN35, CN40, CN45, CN50, and CN55, and F-24, a multi-component jet fuel. The experiments were performed at 50 atm nominal pressure, 4.2 ms nominal reaction times over a temperature range of 900–1800 K, and an equivalence ratio of approximately 1.0. Gas chromatography was used to qualitatively and quantitatively analyze the post shock gases. The relationship between the formation of key intermediate species and the chemically controlled combustion propensity as reflected by the cetane number of each fuel was examined. The oxidation and pyrolysis speciation data were first modeled using a surrogate-based mechanism from the CRECK Modelling Group and chemical-functional group based optimized surrogates (CFGO), showing less than satisfactory agreement. Adjusting the aromatic content of the surrogates led to overall improvements in the oxidation modeling. In the case of pyrolysis, the CFGO surrogate model showed satisfactory agreement in capturing the chemistry of most species except two important pyrolysis intermediates – ethylene and acetylene. Chemical kinetic analyses were performed to identify the important reactions which affect the chemistry of these species; however, the rate parameters of critical reactions were found to be unsuitable for simulating the present high-pressure studies. To address this unsuitability, a theory-based fall-off analysis for three reactions representing the decomposition of ethylene and subsequent formation of acetylene was performed, and these are included in an updated version of the CRECK mechanism. This update resolves discrepancies between the experimental results and simulations for ethylene and acetylene. Rate of production, sensitivity and reaction path analyses using the updated surrogate model showed that the primary reactions responsible for driving the combustion chemistry were largely influenced by the chemical functional groups present in the complex multi-component fuels. In addition to highlighting the effectiveness of the fuel-surrogate approach, where surrogates representing the chemical functional group composition of the parent fuel serve as a valuable tool for predicting the combustion chemistry of novel fuels, the study also underscores the value of updating the rate parameters of specific reactions to improve modeling."],"dc:identifier":["10.25417/uic.31451104.v1"],"dc:relation":["https://figshare.com/articles/thesis/A_Fuel_Surrogate_Approach_to_Model_Combustion_Chemistry_in_Specialty_Jet_Fuels/31451104"],"dc:rights":["In Copyright"],"dc:subject":["Engineering, Mechanical","Combustion","Chemical Kinetics"],"dc:title":["A Fuel Surrogate Approach to Model Combustion Chemistry in Specialty Jet Fuels"],"dc:type":["Text","Thesis"]},"updated_at":"2026-07-27T21:34:21Z"}