{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/99135"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/99135","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Wake deceleration of a racecar multielement airfoil in ground effect","abstract":"The importance of aerodynamic downforce in competitive motorsports has been well established. Much of this aerodynamic downforce is produced from the inverted multielement wings at the front and the rear of the car. While such a high-lift system is capable of producing high downforce as a result of the interaction between flows around adjacent elements, there may exist off-the-surface flow reversal, commonly known as wake bursting, causing an adverse effect on the downforce generated. Since the phenomenon of off-the-surface flow reversal occurs as a result of retardation of a wake under adverse pressure gradients, wake bursting is also referred to as wake deceleration in this study. A steady-state two-dimensional CFD analysis of a racecar multielement airfoil was carried out to study wake deceleration characteristics in ground effect. Simulations were performed using ANSYS Fluent, which is a finite-volume method (FVM) based commercial hybrid-grid Reynolds-averaged Navier-Stokes (RANS) equations solver. Computational results were obtained using a two equation shear stress transport (SST) k–omega model coupled with a one equation intermittency transition model to predict the laminar-to-turbulent boundary layer transition. The simulations were performed for an inverted two-element airfoil consisting of a main element and a flap for a fixed Reynolds number of Re = 1.1 x 10^6. The effects of ground clearance height on the main element decelerated wake were analyzed. The effects of varying flap ratio, flap deflection, angle of attack, and gap sizes on the wake deceleration patterns have been investigated. It was found that decreasing the ground clearance led to a significant increase in the amount of the main element wake bursting. Increased wake bursting at higher angles of attack was found to have caused a drop in downforce without any surface-flow separation. Although the main element wake was strongly affected while varying each of these parameters, the size of the flap wake was not affected significantly.","abstract_html":"The importance of aerodynamic downforce in competitive motorsports has been well established. Much of this aerodynamic downforce is produced from the inverted multielement wings at the front and the rear of the car. While such a high-lift system is capable of producing high downforce as a result of the interaction between flows around adjacent elements, there may exist off-the-surface flow reversal, commonly known as wake bursting, causing an adverse effect on the downforce generated. Since the phenomenon of off-the-surface flow reversal occurs as a result of retardation of a wake under adverse pressure gradients, wake bursting is also referred to as wake deceleration in this study. A steady-state two-dimensional CFD analysis of a racecar multielement airfoil was carried out to study wake deceleration characteristics in ground effect. Simulations were performed using ANSYS Fluent, which is a finite-volume method (FVM) based commercial hybrid-grid Reynolds-averaged Navier-Stokes (RANS) equations solver. Computational results were obtained using a two equation shear stress transport (SST) k–omega model coupled with a one equation intermittency transition model to predict the laminar-to-turbulent boundary layer transition. The simulations were performed for an inverted two-element airfoil consisting of a main element and a flap for a fixed Reynolds number of Re = 1.1 x 10^6. The effects of ground clearance height on the main element decelerated wake were analyzed. The effects of varying flap ratio, flap deflection, angle of attack, and gap sizes on the wake deceleration patterns have been investigated. It was found that decreasing the ground clearance led to a significant increase in the amount of the main element wake bursting. Increased wake bursting at higher angles of attack was found to have caused a drop in downforce without any surface-flow separation. Although the main element wake was strongly affected while varying each of these parameters, the size of the flap wake was not affected significantly.","abstract_has_math":false,"creators":["Bansal, Suraj"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Selig, Michael"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-03-02T20:02:37Z","date_published":"2018-03-02T20:02:37Z","updated_at":"2026-07-22T22:24:37Z","subjects":["Ground effect","Aerodynamics","Multielement","Airfoil","Racecars","Motorsports","Computational fluid dynamics (CFD)","Wake bursting","Wake deceleration"],"languages":["en"],"rights":["Copyright 2017 Suraj Bansal"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/99135","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Selig, Michael"]},{"key":"dc:creator","label":"Author","values":["Bansal, Suraj"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-03-02T20:02:37Z","2020-03-03T10:15:11Z","2017-07-20","2017-08"]},{"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":["Ground effect","Aerodynamics","Multielement","Airfoil","Racecars","Motorsports","Computational fluid dynamics (CFD)","Wake bursting","Wake deceleration"]}]},{"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 Suraj Bansal"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/99135"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The importance of aerodynamic downforce in competitive motorsports has been well established. Much of this aerodynamic downforce is produced from the inverted multielement wings at the front and the rear of the car. While such a high-lift system is capable of producing high downforce as a result of the interaction between flows around adjacent elements, there may exist off-the-surface flow reversal, commonly known as wake bursting, causing an adverse effect on the downforce generated. Since the phenomenon of off-the-surface flow reversal occurs as a result of retardation of a wake under adverse pressure gradients, wake bursting is also referred to as wake deceleration in this study. A steady-state two-dimensional CFD analysis of a racecar multielement airfoil was carried out to study wake deceleration characteristics in ground effect. Simulations were performed using ANSYS Fluent, which is a finite-volume method (FVM) based commercial hybrid-grid Reynolds-averaged Navier-Stokes (RANS) equations solver. Computational results were obtained using a two equation shear stress transport (SST) k–omega model coupled with a one equation intermittency transition model to predict the laminar-to-turbulent boundary layer transition. The simulations were performed for an inverted two-element airfoil consisting of a main element and a flap for a fixed Reynolds number of Re = 1.1 x 10^6. The effects of ground clearance height on the main element decelerated wake were analyzed. The effects of varying flap ratio, flap deflection, angle of attack, and gap sizes on the wake deceleration patterns have been investigated. It was found that decreasing the ground clearance led to a significant increase in the amount of the main element wake bursting. Increased wake bursting at higher angles of attack was found to have caused a drop in downforce without any surface-flow separation. Although the main element wake was strongly affected while varying each of these parameters, the size of the flap wake was not affected significantly.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-08-01","The student, Suraj Bansal, accepted the attached license on 2017-07-20 at 11:24.","The student, Suraj Bansal, submitted this Thesis for approval on 2017-07-20 at 11:46.","This Thesis was approved for publication on 2017-07-20 at 13:02.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11549 on 2018-03-02 at 13:02:51","Made available in DSpace on 2018-03-02T20:02:37Z (GMT). No. of bitstreams: 2 BANSAL-THESIS-2017.pdf: 26192308 bytes, checksum: 3328a78c1867d18fe1fedf03bd987d8c (MD5) LICENSE.txt: 4209 bytes, checksum: d0ebc948af341972ff30bbaaa4e29b62 (MD5) Previous issue date: 2017-07-20","Embargo set by: Seth Robbins for item 105090 Lift date: 2020-03-02T20:02:46Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 105090 on 2020-03-03T10:15:11Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Wake deceleration of a racecar multielement airfoil in ground effect"]}]}],"canonical_facts":{"dc:contributor":["Selig, Michael"],"dc:creator":["Bansal, Suraj"],"dc:date":["2018-03-02T20:02:37Z","2020-03-03T10:15:11Z","2017-07-20","2017-08"],"dc:description":["The importance of aerodynamic downforce in competitive motorsports has been well established. Much of this aerodynamic downforce is produced from the inverted multielement wings at the front and the rear of the car. While such a high-lift system is capable of producing high downforce as a result of the interaction between flows around adjacent elements, there may exist off-the-surface flow reversal, commonly known as wake bursting, causing an adverse effect on the downforce generated. Since the phenomenon of off-the-surface flow reversal occurs as a result of retardation of a wake under adverse pressure gradients, wake bursting is also referred to as wake deceleration in this study. A steady-state two-dimensional CFD analysis of a racecar multielement airfoil was carried out to study wake deceleration characteristics in ground effect. Simulations were performed using ANSYS Fluent, which is a finite-volume method (FVM) based commercial hybrid-grid Reynolds-averaged Navier-Stokes (RANS) equations solver. Computational results were obtained using a two equation shear stress transport (SST) k–omega model coupled with a one equation intermittency transition model to predict the laminar-to-turbulent boundary layer transition. The simulations were performed for an inverted two-element airfoil consisting of a main element and a flap for a fixed Reynolds number of Re = 1.1 x 10^6. The effects of ground clearance height on the main element decelerated wake were analyzed. The effects of varying flap ratio, flap deflection, angle of attack, and gap sizes on the wake deceleration patterns have been investigated. It was found that decreasing the ground clearance led to a significant increase in the amount of the main element wake bursting. Increased wake bursting at higher angles of attack was found to have caused a drop in downforce without any surface-flow separation. Although the main element wake was strongly affected while varying each of these parameters, the size of the flap wake was not affected significantly.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-08-01","The student, Suraj Bansal, accepted the attached license on 2017-07-20 at 11:24.","The student, Suraj Bansal, submitted this Thesis for approval on 2017-07-20 at 11:46.","This Thesis was approved for publication on 2017-07-20 at 13:02.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11549 on 2018-03-02 at 13:02:51","Made available in DSpace on 2018-03-02T20:02:37Z (GMT). No. of bitstreams: 2 BANSAL-THESIS-2017.pdf: 26192308 bytes, checksum: 3328a78c1867d18fe1fedf03bd987d8c (MD5) LICENSE.txt: 4209 bytes, checksum: d0ebc948af341972ff30bbaaa4e29b62 (MD5) Previous issue date: 2017-07-20","Embargo set by: Seth Robbins for item 105090 Lift date: 2020-03-02T20:02:46Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only Restriction Lifted for Item 105090 on 2020-03-03T10:15:11Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/99135"],"dc:language":["en"],"dc:rights":["Copyright 2017 Suraj Bansal"],"dc:subject":["Ground effect","Aerodynamics","Multielement","Airfoil","Racecars","Motorsports","Computational fluid dynamics (CFD)","Wake bursting","Wake deceleration"],"dc:title":["Wake deceleration of a racecar multielement airfoil in ground effect"],"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":"2026-07-22T22:24:37Z"}