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The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics
Ralph, J. S. 2025. The Effect of Eppler E423 Airfoils Pitching on Motorcycle Aerodynamics. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/83d2af18-6d00-4086-80b1-4290d2634f74
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613940543913984 |
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| access_status_str | Open Access |
| author | Ralph, James Stuart |
| author2 | Erfort, Gareth |
| author_browse | Erfort, Gareth Ralph, James Stuart |
| author_facet | Erfort, Gareth Ralph, James Stuart |
| author_sort | Ralph, James Stuart |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Ralph, J. S. 2025. The Effect of Eppler E423 Airfoils Pitching on Motorcycle Aerodynamics. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/83d2af18-6d00-4086-80b1-4290d2634f74 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132265 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:44:07.837Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132265 The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics Ralph, James Stuart Erfort, Gareth Venter, Martin Philip Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering. Pitching (Aerodynamics) Motorcycles -- Aerodynamics Aerofoils -- Testing UCTD Ralph, J. S. 2025. The Effect of Eppler E423 Airfoils Pitching on Motorcycle Aerodynamics. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/83d2af18-6d00-4086-80b1-4290d2634f74 Thesis (MEng)--Stellenbosch University, 2025. ENGLISH ABSTRACT: Research has shown that motorcycles in motion create aerodynamic lift that adversely affects road-holding and can result in a complete loss of grip at the front wheel. Consequently, modern high-performance motorcycles have inverted wings integrated into the bodywork to introduce downforce. The maximum lift coefficient of an airfoil is generally higher at higher Reynolds numbers. An inverted wing integrated in a similar position as current motorcycles that changes the angle of attack based on the Reynolds number can produce more downforce compared to a fixed wing. A force balance was designed to obtain aerodynamic coefficient data, which was used to validate the modeling strategy of a ‘digital wind tunnel’ Computational Fluid Dynamics (CFD) simulation in STAR-CCM+. This modeling strategy could then be applied to scaled and full-scale geometries. The CFD was performed with turbulence and transition modeling to capture the effects of a Laminar Separation Bubble on low Reynolds number Eppler E423 airfoil wings. The full-scale simulation results showed that at a wing angle of attack of 45 degrees and a motorcycle velocity of 200 km/h, a decrease in the lift coefficient of 1700 % was obtained relative to a case without any wings. This decrease, however, was accompanied by a 37.61 % increase in drag coefficient. An overall lack of dependence of the aerodynamic coefficients on the Reynolds number was also found. Further investigation showed that due to the mechanism used to pitch the wing, a vortex was formed, which prevented wing stall and displaced flow into the rider’s direction, resulting in an additional drag increase. The findings highlight the importance of the mechanism used to actuate the wings for active aerodynamics and the necessity of fences at wing tips currently used in motorcycle wing systems for proper vortex control. AFRIKAANSE OPSOMMING: Navorsing toon dat bewegende motorfietse aërodinamiese hefkrag skep wat die padhouvermoë nadelig beïnvloed en kan lei tot ’n algehele verlies aan voorwiel traksie. Gevolglik het moderne hoëprestasiemotorfietse omgekeerde vlerke wat in die bakwerk geïntegreer is om afwaartse krag uit te oefen. Die maksimum hefkoëffisiënt van ’n vleuel is oor die algemeen hoër by hoër Reynolds-getalle. ’n Omgekeerde vleuel wat in ’n soortgelyke posisie as huidige motorfietse geïntegreer is wat die aanvalshoek verander op grond van die Reynolds-nommer, kan meer afwaartse krag lewer in vergelyking met ’n vaste vleuel. ’n Kragbalans is ontwerp om aërodinamiese koëffisiëntdata te versamel, wat gebruik is om die modelleringstrategie van ’n ‘digitale windtonnel’ met Berekenings Vloeimeganika (BVM) in STAR-CCM+ te valideer. Hierdie modelleringstrategie kan dan toegepas word op skaal en volskaalse geometrië. Die BVM is uitgevoer met turbulensie en oorgangsmodellering om die uitwerking van ’n laminêre wegbreekborrel op lae Reynolds-getal Eppler E423-vlerke te ondersoek. Die volskaalse simulasieresultate het getoon dat by ’n vlerkaanvalshoek van 45°en ’n motorfietssnelheid van 200 km/h, daar ’n afname in die hefkoëffisiënt van 1700 % voorkom in vergelyking tot ’n motorfiets sonder enige vlerke. Hierdie afname het egter gepaard gegaan met ’n toename van 37.61 % in sleurskoëffisiënt. ’n Algehele gebrek aan afhanklikheid van die aërodinamiese koëffisiënte aan die Reynolds-getal is ook gevind. Verdere ondersoek het getoon dat as gevolg van die meganisme wat gebruik is om die vlerk op te roteer, ’n draaikolk gevorm word, wat wegbreking by die vlerke verhoed en vloei in die rigting van die drywer verplaas, wat die sleur verhoog . Die bevindinge beklemtoon die belangrikheid van die meganisme wat gebruik word om die vlerke te roteer vir aktiewe lugdinamiese Beheer en die noodsaaklikheid van keerplaate by vlerkpunte wat tans in motorfietsvlerkstelsels gebruik word vir behoorlike draaikolkbeheer. Masters 2025-06-02T08:04:05Z 2025-06-02T08:04:05Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132265 en Stellenbosch University xiv, 105 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Pitching (Aerodynamics) Motorcycles -- Aerodynamics Aerofoils -- Testing UCTD Ralph, James Stuart The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title | The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title_full | The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title_fullStr | The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title_full_unstemmed | The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title_short | The effect of Eppler E423 airfoils pitching on motorcycle aerodynamics |
| title_sort | effect of eppler e423 airfoils pitching on motorcycle aerodynamics |
| topic | Pitching (Aerodynamics) Motorcycles -- Aerodynamics Aerofoils -- Testing UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132265 |
| work_keys_str_mv | AT ralphjamesstuart theeffectofepplere423airfoilspitchingonmotorcycleaerodynamics AT ralphjamesstuart effectofepplere423airfoilspitchingonmotorcycleaerodynamics |