{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/97518"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/97518","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Design and aerodynamic analysis of an airfoil with a bioinspired leading edge device for stall mitigation at low Reynolds number operation","abstract":"Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces, such as flaps or slats, from the wing leading or trailing edges are often used to extend the aerodynamic envelope. One such aerodynamic device is the Alula, a feather structure attached to one of the hand digits of a bird's wing. The alula is extended by birds at high incidence angles and has been shown to improve the stall parameters of the wings. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like leading edge device on the aerodynamic performance of a cambered airfoil (S1223). The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection is varied to modulate the distance of the tip vortex to the wing surface. Boundary layer velocity profile measurements taken at x/c = 1.25 along the chord length and at three locations along the span of the airfoil show fuller BL profiles in the area of influence behind the alula. The resulting re-energizing of the BL at post stall angle of attacks delays flow reversal and separation and decreases associated drag. Results show that as alula deflection ratio increases, the lift coefficient Cl also increase. At post stall angles of attack, the wake velocity deficit zone is shown to reduce in size when the alula is deployed, confirming that the wing adverse pressure gradient is reduced. The results are in strong agreement with the measurements taken on bird wings with alulae. With the ability to change alula parameters such as location, size, deflection and angle, the complete wing configuration can be tuned for mission specific aerodynamic requirements.","abstract_html":"Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces, such as flaps or slats, from the wing leading or trailing edges are often used to extend the aerodynamic envelope. One such aerodynamic device is the Alula, a feather structure attached to one of the hand digits of a bird's wing. The alula is extended by birds at high incidence angles and has been shown to improve the stall parameters of the wings. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like leading edge device on the aerodynamic performance of a cambered airfoil (S1223). The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection is varied to modulate the distance of the tip vortex to the wing surface. Boundary layer velocity profile measurements taken at x/c = 1.25 along the chord length and at three locations along the span of the airfoil show fuller BL profiles in the area of influence behind the alula. The resulting re-energizing of the BL at post stall angle of attacks delays flow reversal and separation and decreases associated drag. Results show that as alula deflection ratio increases, the lift coefficient Cl also increase. At post stall angles of attack, the wake velocity deficit zone is shown to reduce in size when the alula is deployed, confirming that the wing adverse pressure gradient is reduced. The results are in strong agreement with the measurements taken on bird wings with alulae. With the ability to change alula parameters such as location, size, deflection and angle, the complete wing configuration can be tuned for mission specific aerodynamic requirements.","abstract_has_math":false,"creators":["Mandadzhiev, Boris Atanasov"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Wissa, Aimy A","Chamorro, Leonardo P."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-08-10T19:16:24Z","date_published":"2017-08-10T19:16:24Z","updated_at":"2026-07-22T22:24:34Z","subjects":["Bio-inspired","Leading edge","Airfoil","Wing","Alula","Experimental testing","Wind tunnel","Particle image velocimetry (PIV)","Hot-wire","Bird wing","Avian flight"],"languages":["en"],"rights":["Copyright 2017 Boris Mandadzhiev"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/97518","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Wissa, Aimy A","Chamorro, Leonardo P."]},{"key":"dc:creator","label":"Author","values":["Mandadzhiev, Boris Atanasov"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017-08-10T19:16:24Z","2017-04-28","2017-05"]},{"key":"dc:type","label":"Dc Type","values":["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":["Bio-inspired","Leading edge","Airfoil","Wing","Alula","Experimental testing","Wind tunnel","Particle image velocimetry (PIV)","Hot-wire","Bird wing","Avian flight"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Boris Mandadzhiev"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/97518"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces, such as flaps or slats, from the wing leading or trailing edges are often used to extend the aerodynamic envelope. One such aerodynamic device is the Alula, a feather structure attached to one of the hand digits of a bird's wing. The alula is extended by birds at high incidence angles and has been shown to improve the stall parameters of the wings. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like leading edge device on the aerodynamic performance of a cambered airfoil (S1223). The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection is varied to modulate the distance of the tip vortex to the wing surface. Boundary layer velocity profile measurements taken at x/c = 1.25 along the chord length and at three locations along the span of the airfoil show fuller BL profiles in the area of influence behind the alula. The resulting re-energizing of the BL at post stall angle of attacks delays flow reversal and separation and decreases associated drag. Results show that as alula deflection ratio increases, the lift coefficient Cl also increase. At post stall angles of attack, the wake velocity deficit zone is shown to reduce in size when the alula is deployed, confirming that the wing adverse pressure gradient is reduced. The results are in strong agreement with the measurements taken on bird wings with alulae. With the ability to change alula parameters such as location, size, deflection and angle, the complete wing configuration can be tuned for mission specific aerodynamic requirements.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Boris Mandadzhiev, accepted the attached license on 2017-04-28 at 14:43.","The student, Boris Mandadzhiev, submitted this Thesis for approval on 2017-04-28 at 14:57.","This Thesis was approved for publication on 2017-04-28 at 15:48.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11138 on 2017-08-10 at 13:47:05","Made available in DSpace on 2017-08-10T19:16:24Z (GMT). No. of bitstreams: 2 MANDADZHIEV-THESIS-2017.pdf: 14248084 bytes, checksum: aa83b5834894d1bb78a545e0b6e80154 (MD5) LICENSE.txt: 4214 bytes, checksum: a4ff51baefd264faaf4d428b1660aa96 (MD5) Previous issue date: 2017-04-28"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Design and aerodynamic analysis of an airfoil with a bioinspired leading edge device for stall mitigation at low Reynolds number operation"]}]}],"canonical_facts":{"dc:contributor":["Wissa, Aimy A","Chamorro, Leonardo P."],"dc:creator":["Mandadzhiev, Boris Atanasov"],"dc:date":["2017-08-10T19:16:24Z","2017-04-28","2017-05"],"dc:description":["Robust and predictable aerodynamic performance of unmanned aerial vehicles at the limits of their design envelope is critical for safety and mission adaptability. Deployable aerodynamic surfaces, such as flaps or slats, from the wing leading or trailing edges are often used to extend the aerodynamic envelope. One such aerodynamic device is the Alula, a feather structure attached to one of the hand digits of a bird's wing. The alula is extended by birds at high incidence angles and has been shown to improve the stall parameters of the wings. In this study, a series of wind tunnel experiments are performed to quantify the effect of various deployment parameters of an alula-like leading edge device on the aerodynamic performance of a cambered airfoil (S1223). The alula relative angle of attack, measured from the mean chord of the airfoil, is varied to modulate tip-vortex strength, while the alula deflection is varied to modulate the distance of the tip vortex to the wing surface. Boundary layer velocity profile measurements taken at x/c = 1.25 along the chord length and at three locations along the span of the airfoil show fuller BL profiles in the area of influence behind the alula. The resulting re-energizing of the BL at post stall angle of attacks delays flow reversal and separation and decreases associated drag. Results show that as alula deflection ratio increases, the lift coefficient Cl also increase. At post stall angles of attack, the wake velocity deficit zone is shown to reduce in size when the alula is deployed, confirming that the wing adverse pressure gradient is reduced. The results are in strong agreement with the measurements taken on bird wings with alulae. With the ability to change alula parameters such as location, size, deflection and angle, the complete wing configuration can be tuned for mission specific aerodynamic requirements.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo terms","The student, Boris Mandadzhiev, accepted the attached license on 2017-04-28 at 14:43.","The student, Boris Mandadzhiev, submitted this Thesis for approval on 2017-04-28 at 14:57.","This Thesis was approved for publication on 2017-04-28 at 15:48.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11138 on 2017-08-10 at 13:47:05","Made available in DSpace on 2017-08-10T19:16:24Z (GMT). No. of bitstreams: 2 MANDADZHIEV-THESIS-2017.pdf: 14248084 bytes, checksum: aa83b5834894d1bb78a545e0b6e80154 (MD5) LICENSE.txt: 4214 bytes, checksum: a4ff51baefd264faaf4d428b1660aa96 (MD5) Previous issue date: 2017-04-28"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/97518"],"dc:language":["en"],"dc:rights":["Copyright 2017 Boris Mandadzhiev"],"dc:subject":["Bio-inspired","Leading edge","Airfoil","Wing","Alula","Experimental testing","Wind tunnel","Particle image velocimetry (PIV)","Hot-wire","Bird wing","Avian flight"],"dc:title":["Design and aerodynamic analysis of an airfoil with a bioinspired leading edge device for stall mitigation at low Reynolds number operation"],"dc:type":["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":"2026-07-22T22:24:34Z"}