{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/72238"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/72238","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Modeling and Experimental Measurements of Laser-Sustained Hydrogen Plasmas","abstract":"Laser propulsion is an advanced propulsion concept especially applicable to orbital transfer vehicles. As an alternative to combusting fuel and oxidizer, the concept utilizes a remote laser beam as a source of power. A laser sustained plasma (LSP) is the medium by which power is absorbed by the beam and transferred to the propellant.","abstract_html":"Laser propulsion is an advanced propulsion concept especially applicable to orbital transfer vehicles. As an alternative to combusting fuel and oxidizer, the concept utilizes a remote laser beam as a source of power. A laser sustained plasma (LSP) is the medium by which power is absorbed by the beam and transferred to the propellant.","abstract_has_math":false,"creators":["Mertogul, Ayhan Ergun"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Krier, Herman"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-17T21:26:17Z","date_published":"2014-12-17T21:26:17Z","updated_at":"2026-07-22T22:26:06Z","subjects":["Engineering, Aerospace","Engineering, Mechanical","Physics, Fluid and Plasma"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI9329113"],"render_values":[{"text":"(UMI)AAI9329113","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/72238","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Krier, Herman"]},{"key":"dc:creator","label":"Author","values":["Mertogul, Ayhan Ergun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-17T21:26:17Z","10000-01-01","1993"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"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 at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Aerospace","Engineering, Mechanical","Physics, Fluid and Plasma"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/72238","(UMI)AAI9329113"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Laser propulsion is an advanced propulsion concept especially applicable to orbital transfer vehicles. As an alternative to combusting fuel and oxidizer, the concept utilizes a remote laser beam as a source of power. A laser sustained plasma (LSP) is the medium by which power is absorbed by the beam and transferred to the propellant.","Experiments have been performed which measured global absorption and thermal efficiency of laser sustained hydrogen plasmas for the first time. Effects of variations of laser power, hydrogen mole flux, absorption chamber pressure, and beam focusing geometry have been observed. The mole flux stability limits for a variety of conditions have been recorded. Results include global absorption as high as 90% and thermal efficiency as high as 80%. These results validate laser propulsion as a feasible orbital transfer technology.","In addition, a generalized non-local thermodynamic equilibrium model of laser sustained hydrogen plasmas has been formulated. The generalized model includes methodology for the computation of the second Chapman-Enskog approximation for global viscosity, as well as the third approximations for electron thermal conductivity, heavy species thermal conductivity, thermal diffusion coefficients, and multicomponent diffusion coefficients. The generalized model also includes a collisional-radiative rate model with 27 individual reactions involving all seven hydrogen plasma species and 35 discretized radiation bands.","A simplified kinetic nonequilibrium model of laser sustained hydrogen plasmas has been formulated and solved. This model is the first of its kind and includes a discretized beam raytrace with a variable index of refraction based upon plasma electron number density. Model results have compared favorably with experimental results and the model has been used to provide predictions of LSP performance well outside the realm of experiments. Multiple model solutions have been obtained which are dependent upon initial conditions. No significant kinetic nonequilibrium was observed in LSP core regions for incident powers up to 700 kW. Beam refraction by the LSP has been observed to have a major effect on LSP performance.","Made available in DSpace on 2014-12-17T21:26:17Z (GMT). No. of bitstreams: 1 9329113.pdf: 17395108 bytes, checksum: 769253efb9a3a3d90495c8955d06b77b (MD5) Previous issue date: 1993","Embargo set by: Seth Robbins for item 72406 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","385 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993."]},{"key":"dc:title","label":"Title","values":["Modeling and Experimental Measurements of Laser-Sustained Hydrogen Plasmas"]}]}],"canonical_facts":{"dc:contributor":["Krier, Herman"],"dc:creator":["Mertogul, Ayhan Ergun"],"dc:date":["2014-12-17T21:26:17Z","10000-01-01","1993"],"dc:description":["Laser propulsion is an advanced propulsion concept especially applicable to orbital transfer vehicles. As an alternative to combusting fuel and oxidizer, the concept utilizes a remote laser beam as a source of power. A laser sustained plasma (LSP) is the medium by which power is absorbed by the beam and transferred to the propellant.","Experiments have been performed which measured global absorption and thermal efficiency of laser sustained hydrogen plasmas for the first time. Effects of variations of laser power, hydrogen mole flux, absorption chamber pressure, and beam focusing geometry have been observed. The mole flux stability limits for a variety of conditions have been recorded. Results include global absorption as high as 90% and thermal efficiency as high as 80%. These results validate laser propulsion as a feasible orbital transfer technology.","In addition, a generalized non-local thermodynamic equilibrium model of laser sustained hydrogen plasmas has been formulated. The generalized model includes methodology for the computation of the second Chapman-Enskog approximation for global viscosity, as well as the third approximations for electron thermal conductivity, heavy species thermal conductivity, thermal diffusion coefficients, and multicomponent diffusion coefficients. The generalized model also includes a collisional-radiative rate model with 27 individual reactions involving all seven hydrogen plasma species and 35 discretized radiation bands.","A simplified kinetic nonequilibrium model of laser sustained hydrogen plasmas has been formulated and solved. This model is the first of its kind and includes a discretized beam raytrace with a variable index of refraction based upon plasma electron number density. Model results have compared favorably with experimental results and the model has been used to provide predictions of LSP performance well outside the realm of experiments. Multiple model solutions have been obtained which are dependent upon initial conditions. No significant kinetic nonequilibrium was observed in LSP core regions for incident powers up to 700 kW. Beam refraction by the LSP has been observed to have a major effect on LSP performance.","Made available in DSpace on 2014-12-17T21:26:17Z (GMT). No. of bitstreams: 1 9329113.pdf: 17395108 bytes, checksum: 769253efb9a3a3d90495c8955d06b77b (MD5) Previous issue date: 1993","Embargo set by: Seth Robbins for item 72406 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","385 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1993."],"dc:identifier":["http://hdl.handle.net/2142/72238","(UMI)AAI9329113"],"dc:subject":["Engineering, Aerospace","Engineering, Mechanical","Physics, Fluid and Plasma"],"dc:title":["Modeling and Experimental Measurements of Laser-Sustained Hydrogen Plasmas"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:06Z"}