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Vortex Generators. AOE 4124 Dr. Mason March 26, 2004 Rich Stark Brian Squires Jessica Walker. Definition of Vortex Generators. According to Clancy in “Aerodynamics” (Ref 1.) :
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Vortex Generators AOE 4124 Dr. Mason March 26, 2004 Rich Stark Brian Squires Jessica Walker
Definition of Vortex Generators • According to Clancy in “Aerodynamics” (Ref 1.) : • Vortex generators are small, cambered, thin airfoils placed to introduce swirling motions that energize the boundary layer causing a delay in stall.
Common Applications • External – Fuselage/Wing • Upstream of flight control surfaces where BL attachment is critical • Internal – Propulsion • Prevents flow separation, excessive BL growth, and to reduce total pressure distortion of the flow ingested by the engine Ref. 2: Wendt, B.J. and B.A. Reichert, “The Modelling of Symmetric Airfoil Vortex Generators.” AIAA Paper 96-0807.
History of Vortex Generators • First used in England (inventor unknown) • Used first on Transport Jets and Bizjets • Used as a “band-aid” for localized mach buffeting problems • First GA applications on Cessna 206 and Baron D-55
How They Work • Create strong tip vortices which feed high energy air from the external stream to mix with/replace the slower moving air in the boundary layer • Reduces the effects of adverse pressure gradients and prevents separation Ref. 3 http://home1.gte.net.pjbemail/VortexGen.html
Flow Effects of VGs Ref. 4 www.avweb.com/news/reviews/182564-1.html
Shed Vortex Structure Ref. 5 Klausmeyer, Steven; Papadakis, Michael; and Lin, John, “A Flow Physics Study of Vortex Generators on a Multi-element Airfoil.” AIAA Paper 96-0548
VG Effect on CL at Various Angles of Attack Ref. 6 Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Generator Position and Orientation on Highly Swept Wings.” AIAA-97-2319
Arrangement of VGs • Usually located at the transition from laminar to turbulent flow • Typically 80% of boundary layer thickness Ref. 4 www.avweb.com/news/reviews/182564-1.html
Various GA Aircraft Models Which Offer VG Kits • BEECHDuke 60, A60, B60, Bonanza 33, 35, 36, 36TCCESSNA120/140Skywagon 180, 185310, 310A-R, T310P-R320D-F335, 340, 340A401, 401A, 401B402, 402A, 402B, 402C414, 414A421, 421A, 421B, 421C441 (Conquest II) • deHAVILLANDBeaver Mk I Ref. 7 www.airliners.net/info
Various GA Aircraft Models Which Offer VG Kits (cont.) • PIPERNavajo PA31-310, 325C/RColemill Panther I & IIChieftan PA31-350, T1020Seneca II/III/IV PA34Super Cruiser PA12, PA14Super Cub PA18 • AGPLANESAyres Thrush, Air Tractor,Cessna 188 AgWagon,Piper PA36 Brave, Dromader, Weatherly Ref. 7 www.airliners.net/info
Commercial Transport Aircraft with VGs Ref. 7 www.airliners.net/info
Pros and Cons • Pros: • Increases slope of lift curve • Increase in Gross Take-off Weight • Stall speed reduction (7-21%) • Improved handling qualities • Decrease tire and brake wear • Cons: • Expensive • Makes debugging of the leading edge difficult • Possible source of vibration • Dual instruction and practice required for full effectiveness
More Pros • Shorter take-offs and landings • Steeper climb-outs and approaches • Reduction of min control speed • No extra drag • No weight and balance change • No extra maintainence
VGs are Everywhere! Ref. 8 www.greenwoodcorvettes.net
Go Faster Strip Ref. 3 http://home1.gte.net.pjbemail/VortexGen.html
Head Mounted Vortex Generators Ref. 3 http://home1.gte.net.pjbemail/VortexGen.html
References • Clancy, L.J. “Aerodynamics.” Halsted Press, 1975. • Wendt, B.J. and B.A. Reichert, “The Modelling of Symmetric Airfoil Vortex Generators.” AIAA Paper 96-0807. • http://home1.gte.net.pjbemail/VortexGen.html • www.avweb.com/news/reviews/182564-1.html • Klausmeyer, Steven; Papadakis, Michael; and Lin, John, “A Flow Physics Study of Vortex Generators on a Multi-element Airfoil.” AIAA Paper 96-0548 • Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Generator Position and Orientation on Highly Swept Wings.” AIAA-97-2319 • www.airliners.net/info • www.greenwoodcorvettes.net • Animated vortex on title page taken from ref. 3