{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/108498"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/108498","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Assessment of hypersonic separation dynamics for drag modulation entry systems at Mars","abstract":"Made available in DSpace on 2020-10-07T20:59:54Z (GMT). No. of bitstreams: 3 MCCLARY-THESIS-2020.pdf: 3194461 bytes, checksum: 431d6e9fb215785efc6549ed18429060 (MD5) McClary_Thesis.zip: 8962237 bytes, checksum: b48eb5bcba7119fa05fc9353ff673688 (MD5) LICENSE.txt: 4213 bytes, checksum: d93ad071ca4fecebd105abaa6be18aba (MD5) Previous issue date: 2020-07-21","abstract_html":"Made available in DSpace on 2020-10-07T20:59:54Z (GMT). No. of bitstreams: 3 MCCLARY-THESIS-2020.pdf: 3194461 bytes, checksum: 431d6e9fb215785efc6549ed18429060 (MD5) McClary_Thesis.zip: 8962237 bytes, checksum: b48eb5bcba7119fa05fc9353ff673688 (MD5) LICENSE.txt: 4213 bytes, checksum: d93ad071ca4fecebd105abaa6be18aba (MD5) Previous issue date: 2020-07-21","abstract_has_math":false,"creators":["McClary, Michelle"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Putnam, Zachary R"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-10-07T20:59:54Z","date_published":"2020-10-07T20:59:54Z","updated_at":"2026-07-22T22:24:48Z","subjects":["Discrete-Event Drag Modulation","Drag Modulation Separation Dynamics","Drag Modulation Recontact Analysis"],"languages":["en"],"rights":["Copyright 2020 Michelle McClary and Dr. Zachary Putnam"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/108498","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Putnam, Zachary R"]},{"key":"dc:creator","label":"Author","values":["McClary, Michelle"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2020-10-07T20:59:54Z","2020-07-21","2020-08"]},{"key":"dc:type","label":"Dc Type","values":["Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Discrete-Event Drag Modulation","Drag Modulation Separation Dynamics","Drag Modulation Recontact Analysis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2020 Michelle McClary and Dr. Zachary Putnam"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/108498"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Made available in DSpace on 2020-10-07T20:59:54Z (GMT). No. of bitstreams: 3 MCCLARY-THESIS-2020.pdf: 3194461 bytes, checksum: 431d6e9fb215785efc6549ed18429060 (MD5) McClary_Thesis.zip: 8962237 bytes, checksum: b48eb5bcba7119fa05fc9353ff673688 (MD5) LICENSE.txt: 4213 bytes, checksum: d93ad071ca4fecebd105abaa6be18aba (MD5) Previous issue date: 2020-07-21","This thesis presents an analysis of the hypersonic separation dynamics for a drag modulation entry system, consisting of a planetary entry vehicle and deployable drag area, that performs a jettison event during planetary entry or aerocapture. The entry vehicle is modeled as a blunted spherecone and the deployable drag area is modeled as a conical frustum. Hypersonic aerodynamic coefficients are obtained with Newtonian Aerodynamics. The first portion of the thesis identifies separation times for a range of vehicle parameters and flight conditions which includes vehicle size, drag area size, and jettison velocity. For a given entry trajectory, a minimum separation time is found for a jettison velocity that corresponds to maximum dynamic pressure. Results show that entry vehicles with a larger initial ballistic coefficient will require less time to achieve a separation distance of one drag area aft radius in addition to a smaller range of separation times over possible jettison conditions. The second portion of this work determines if recontact occurs between the two bodies after jettison and explores the affect of applying an impulse to the drag area at jettison to improve jettison performance. Emphasis is placed on determining what flight conditions lead to a recontact-free jettison event and, for jettison events that are not successful, how large of an impulse must be applied to prevent recontact. Results indicate recontact is most likely to occur at jettison conditions with low dynamic pressures and an impulse is required when jettison occurs with large angle of attack and angle of attack rates in conjunction with small differences in ballistic coefficient between the entry vehicle and drag area. Sensitivity analysis is performed to determine which conditions are most important to the success of the jettison event. Results show that the difference in ballistic coefficient between entry vehicle and drag area is the most influential parameter in determining the recontact-free jettison envelope. This envelope can be manipulated through moving the drag area center of gravity off of the axis of symmetry. Overall, results indicate a successful jettison, with no recontact, is possible and likely for typical blunt body spherecone entry trajectories and attitude dynamics. Minimizing the chance of recontact for entry trajectories can be achieved through a jettison event closer to maximum dynamic pressure which will also reduce the time to separate.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-10-02 without embargo terms","The student, Michelle McClary, accepted the attached license on 2020-07-15 at 09:35.","The student, Michelle McClary, submitted this Thesis for approval on 2020-07-15 at 10:00.","This Thesis was approved for publication on 2020-07-21 at 16:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15628 on 2020-10-02 at 15:13:51"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Assessment of hypersonic separation dynamics for drag modulation entry systems at Mars"]}]}],"canonical_facts":{"dc:contributor":["Putnam, Zachary R"],"dc:creator":["McClary, Michelle"],"dc:date":["2020-10-07T20:59:54Z","2020-07-21","2020-08"],"dc:description":["Made available in DSpace on 2020-10-07T20:59:54Z (GMT). No. of bitstreams: 3 MCCLARY-THESIS-2020.pdf: 3194461 bytes, checksum: 431d6e9fb215785efc6549ed18429060 (MD5) McClary_Thesis.zip: 8962237 bytes, checksum: b48eb5bcba7119fa05fc9353ff673688 (MD5) LICENSE.txt: 4213 bytes, checksum: d93ad071ca4fecebd105abaa6be18aba (MD5) Previous issue date: 2020-07-21","This thesis presents an analysis of the hypersonic separation dynamics for a drag modulation entry system, consisting of a planetary entry vehicle and deployable drag area, that performs a jettison event during planetary entry or aerocapture. The entry vehicle is modeled as a blunted spherecone and the deployable drag area is modeled as a conical frustum. Hypersonic aerodynamic coefficients are obtained with Newtonian Aerodynamics. The first portion of the thesis identifies separation times for a range of vehicle parameters and flight conditions which includes vehicle size, drag area size, and jettison velocity. For a given entry trajectory, a minimum separation time is found for a jettison velocity that corresponds to maximum dynamic pressure. Results show that entry vehicles with a larger initial ballistic coefficient will require less time to achieve a separation distance of one drag area aft radius in addition to a smaller range of separation times over possible jettison conditions. The second portion of this work determines if recontact occurs between the two bodies after jettison and explores the affect of applying an impulse to the drag area at jettison to improve jettison performance. Emphasis is placed on determining what flight conditions lead to a recontact-free jettison event and, for jettison events that are not successful, how large of an impulse must be applied to prevent recontact. Results indicate recontact is most likely to occur at jettison conditions with low dynamic pressures and an impulse is required when jettison occurs with large angle of attack and angle of attack rates in conjunction with small differences in ballistic coefficient between the entry vehicle and drag area. Sensitivity analysis is performed to determine which conditions are most important to the success of the jettison event. Results show that the difference in ballistic coefficient between entry vehicle and drag area is the most influential parameter in determining the recontact-free jettison envelope. This envelope can be manipulated through moving the drag area center of gravity off of the axis of symmetry. Overall, results indicate a successful jettison, with no recontact, is possible and likely for typical blunt body spherecone entry trajectories and attitude dynamics. Minimizing the chance of recontact for entry trajectories can be achieved through a jettison event closer to maximum dynamic pressure which will also reduce the time to separate.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2020-10-02 without embargo terms","The student, Michelle McClary, accepted the attached license on 2020-07-15 at 09:35.","The student, Michelle McClary, submitted this Thesis for approval on 2020-07-15 at 10:00.","This Thesis was approved for publication on 2020-07-21 at 16:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #15628 on 2020-10-02 at 15:13:51"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/108498"],"dc:language":["en"],"dc:rights":["Copyright 2020 Michelle McClary and Dr. Zachary Putnam"],"dc:subject":["Discrete-Event Drag Modulation","Drag Modulation Separation Dynamics","Drag Modulation Recontact Analysis"],"dc:title":["Assessment of hypersonic separation dynamics for drag modulation entry systems at Mars"],"dc:type":["Thesis","text"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:48Z"}