{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/44858"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/44858","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Afterbody drag prediction for conceptual aircraft design","abstract":"With the increasing performance demands placed on aircraft, the nozzle is becoming a much more versatile component. This versatility is increasing the afterbody complexity and the difficulty in afterbody drag prediction. This thesis documents a computationally inexpensive method for estimating the afterbody drag of aircraft during the conceptual design stage. The design and creation of a new hybrid approach to afterbody drag prediction is discussed. This hybrid approach uses the Integral Mean Slope Truncated Method in place of an equivalent body of revolution pressure drag. Corrections or drag deltas are then applied to the Integral Mean Slope Truncated afterbody drag estimate. These drag deltas account for various geometric effects and three-dimensional effects. The resulting prediction method is applicable to both axisymmetric and 2-D nozzles. The hybrid approach has been incorporated into ACSYNT Version 2.0.0 (AirCraft SYNThesis), a conceptual aircraft design tool developed at NASA Ames Research Center and Virginia Polytechnic Institute and State University. Comparison of the predictions of the new hybrid approach with those of a more complex and much more computationally expensive method show generally good agreement.","abstract_html":"With the increasing performance demands placed on aircraft, the nozzle is becoming a much more versatile component. This versatility is increasing the afterbody complexity and the difficulty in afterbody drag prediction. This thesis documents a computationally inexpensive method for estimating the afterbody drag of aircraft during the conceptual design stage. The design and creation of a new hybrid approach to afterbody drag prediction is discussed. This hybrid approach uses the Integral Mean Slope Truncated Method in place of an equivalent body of revolution pressure drag. Corrections or drag deltas are then applied to the Integral Mean Slope Truncated afterbody drag estimate. These drag deltas account for various geometric effects and three-dimensional effects. The resulting prediction method is applicable to both axisymmetric and 2-D nozzles. The hybrid approach has been incorporated into ACSYNT Version 2.0.0 (AirCraft SYNThesis), a conceptual aircraft design tool developed at NASA Ames Research Center and Virginia Polytechnic Institute and State University. Comparison of the predictions of the new hybrid approach with those of a more complex and much more computationally expensive method show generally good agreement.","abstract_has_math":false,"creators":["Squire, Douglas J."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Aerospace Engineering","degree_department":"Aerospace Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1992,"date_issued":"1992","date_published":"1992","updated_at":"2026-07-22T22:19:57Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-09192009-040348"],"render_values":[{"text":"etd-09192009-040348","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/44858","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Aerospace Engineering"]},{"key":"dc:creator","label":"Author","values":["Squire, Douglas J."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:46:10Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:46:10Z","2009-09-19"]},{"key":"dc:date.issued","label":"Date","values":["1992"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-09192009-040348"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/44858"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["With the increasing performance demands placed on aircraft, the nozzle is becoming a much more versatile component. 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Comparison of the predictions of the new hybrid approach with those of a more complex and much more computationally expensive method show generally good agreement."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Afterbody drag prediction for conceptual aircraft design"]}]}],"canonical_facts":{"dc:contributor.department":["Aerospace Engineering"],"dc:creator":["Squire, Douglas J."],"dc:date.accessioned":["2014-03-14T21:46:10Z"],"dc:date.available":["2014-03-14T21:46:10Z","2009-09-19"],"dc:date.issued":["1992"],"dc:description.abstract":["With the increasing performance demands placed on aircraft, the nozzle is becoming a much more versatile component. 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