{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/132628"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/132628","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Laser absorption spectroscopy for investigation of hypersonic propulsion","abstract":"Advancements in scramjet technology have arisen from recent interest in hypersonic propulsion. Progress in ground-testing capabilities has accelerated this technological advancement, providing repeatable and controllable experimentation at lower costs than flight tests. A primary challenge of carrying out experiments in these ground test facilities is replicating exact conditions representative of the hypersonic flight environment. Generating high enthalpy conditions often produces a test gas with an altered chemical composition, which can influence combustion performance downstream. This dissertation first addresses this issue by characterizing the inflow gas in the ACT-II facility, using tunable diode laser absorption spectroscopy (TDLAS) to measure temperature and nitric oxide (NO) concentration. Another fundamental challenge associated with scramjet operation is achieving efficient fuel-air mixing and ignition within the short residence times of a scramjet combustor. Because thrust generation is strongly influenced by combustion performance, the next section of this dissertation details the development and demonstration of TDLAS sensors for combustion characterization. Simultaneous carbon monoxide (CO) and carbon dioxide (CO2) concentration measurements characterize combustion performance for different combustor geometries and fueling schemes. Finally, the last portion of the dissertation demonstrates a diagnostic for future scramjet applications. Water vapor absorption spectroscopy using a broad-bandwidth laser is demonstrated in a shock tube for temperature and pressure measurements in a simulated combustion environment. The work represents potential for an additional combustion product measurement in a scramjet.","abstract_html":"Advancements in scramjet technology have arisen from recent interest in hypersonic propulsion. Progress in ground-testing capabilities has accelerated this technological advancement, providing repeatable and controllable experimentation at lower costs than flight tests. A primary challenge of carrying out experiments in these ground test facilities is replicating exact conditions representative of the hypersonic flight environment. Generating high enthalpy conditions often produces a test gas with an altered chemical composition, which can influence combustion performance downstream. This dissertation first addresses this issue by characterizing the inflow gas in the ACT-II facility, using tunable diode laser absorption spectroscopy (TDLAS) to measure temperature and nitric oxide (NO) concentration. Another fundamental challenge associated with scramjet operation is achieving efficient fuel-air mixing and ignition within the short residence times of a scramjet combustor. Because thrust generation is strongly influenced by combustion performance, the next section of this dissertation details the development and demonstration of TDLAS sensors for combustion characterization. Simultaneous carbon monoxide (CO) and carbon dioxide (CO2) concentration measurements characterize combustion performance for different combustor geometries and fueling schemes. Finally, the last portion of the dissertation demonstrates a diagnostic for future scramjet applications. Water vapor absorption spectroscopy using a broad-bandwidth laser is demonstrated in a shock tube for temperature and pressure measurements in a simulated combustion environment. The work represents potential for an additional combustion product measurement in a scramjet.","abstract_has_math":false,"creators":["Gessman, Isabella"],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Lee, Tonghun","Cai, Lili","Glumac, Nick","Panerai, Francesco"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-12","date_published":"2025-12","updated_at":"2026-07-22T22:25:07Z","subjects":["hypersonics","scramjets","laser diagnostics","laser absorption spectroscopy"],"languages":["en"],"rights":["Copyright 2025 Isabella Gessman"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/132628","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lee, Tonghun","Cai, Lili","Glumac, Nick","Panerai, Francesco"]},{"key":"dc:creator","label":"Author","values":["Gessman, Isabella"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-12","2025-10-07"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["hypersonics","scramjets","laser diagnostics","laser absorption spectroscopy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Isabella Gessman"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/132628"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Advancements in scramjet technology have arisen from recent interest in hypersonic propulsion. Progress in ground-testing capabilities has accelerated this technological advancement, providing repeatable and controllable experimentation at lower costs than flight tests. A primary challenge of carrying out experiments in these ground test facilities is replicating exact conditions representative of the hypersonic flight environment. Generating high enthalpy conditions often produces a test gas with an altered chemical composition, which can influence combustion performance downstream. This dissertation first addresses this issue by characterizing the inflow gas in the ACT-II facility, using tunable diode laser absorption spectroscopy (TDLAS) to measure temperature and nitric oxide (NO) concentration. Another fundamental challenge associated with scramjet operation is achieving efficient fuel-air mixing and ignition within the short residence times of a scramjet combustor. Because thrust generation is strongly influenced by combustion performance, the next section of this dissertation details the development and demonstration of TDLAS sensors for combustion characterization. Simultaneous carbon monoxide (CO) and carbon dioxide (CO2) concentration measurements characterize combustion performance for different combustor geometries and fueling schemes. Finally, the last portion of the dissertation demonstrates a diagnostic for future scramjet applications. Water vapor absorption spectroscopy using a broad-bandwidth laser is demonstrated in a shock tube for temperature and pressure measurements in a simulated combustion environment. The work represents potential for an additional combustion product measurement in a scramjet.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-12-01","The student, Isabella Gessman, accepted the attached license on 2025-10-06 at 13:43.","The student, Isabella Gessman, submitted this Dissertation for approval on 2025-10-06 at 14:06.","This Dissertation was approved for publication on 2025-10-07 at 13:18.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22820 on 2026-02-19 at 18:45:35"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Laser absorption spectroscopy for investigation of hypersonic propulsion"]}]}],"canonical_facts":{"dc:contributor":["Lee, Tonghun","Cai, Lili","Glumac, Nick","Panerai, Francesco"],"dc:creator":["Gessman, Isabella"],"dc:date":["2025-12","2025-10-07"],"dc:description":["Advancements in scramjet technology have arisen from recent interest in hypersonic propulsion. Progress in ground-testing capabilities has accelerated this technological advancement, providing repeatable and controllable experimentation at lower costs than flight tests. A primary challenge of carrying out experiments in these ground test facilities is replicating exact conditions representative of the hypersonic flight environment. Generating high enthalpy conditions often produces a test gas with an altered chemical composition, which can influence combustion performance downstream. This dissertation first addresses this issue by characterizing the inflow gas in the ACT-II facility, using tunable diode laser absorption spectroscopy (TDLAS) to measure temperature and nitric oxide (NO) concentration. Another fundamental challenge associated with scramjet operation is achieving efficient fuel-air mixing and ignition within the short residence times of a scramjet combustor. Because thrust generation is strongly influenced by combustion performance, the next section of this dissertation details the development and demonstration of TDLAS sensors for combustion characterization. Simultaneous carbon monoxide (CO) and carbon dioxide (CO2) concentration measurements characterize combustion performance for different combustor geometries and fueling schemes. Finally, the last portion of the dissertation demonstrates a diagnostic for future scramjet applications. Water vapor absorption spectroscopy using a broad-bandwidth laser is demonstrated in a shock tube for temperature and pressure measurements in a simulated combustion environment. The work represents potential for an additional combustion product measurement in a scramjet.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-12-01","The student, Isabella Gessman, accepted the attached license on 2025-10-06 at 13:43.","The student, Isabella Gessman, submitted this Dissertation for approval on 2025-10-06 at 14:06.","This Dissertation was approved for publication on 2025-10-07 at 13:18.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22820 on 2026-02-19 at 18:45:35"],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/132628"],"dc:language":["en"],"dc:rights":["Copyright 2025 Isabella Gessman"],"dc:subject":["hypersonics","scramjets","laser diagnostics","laser absorption spectroscopy"],"dc:title":["Laser absorption spectroscopy for investigation of hypersonic propulsion"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:07Z"}