Vortex GeneratorsVortex Generators

AOE 4124 Dr. MasonAOE 4124 Dr. MasonMarch 26, 2004March 26, 2004Rich StarkRich StarkBrian SquiresBrian SquiresJessica WalkerJessica Walker

Definition of Vortex Definition of Vortex GeneratorsGenerators According to Clancy in According to Clancy in

“Aerodynamics” (Ref 1.) :“Aerodynamics” (Ref 1.) :

– Vortex generators are small, Vortex generators are small, cambered, thin airfoils placed to cambered, thin airfoils placed to introduce swirling motions that introduce swirling motions that energize the boundary layer causing energize the boundary layer causing a delay in stall.a delay in stall.

Common ApplicationsCommon Applications

External – External – Fuselage/WingFuselage/Wing– Upstream of flight Upstream of flight

control surfaces control surfaces where BL attachment where BL attachment is criticalis critical

Internal – PropulsionInternal – Propulsion– Prevents flow Prevents flow

separation, excessive separation, excessive BL growth, and to BL growth, and to reduce total pressure reduce total pressure distortion of the flow distortion of the flow ingested by the ingested by the engineengine

Ref. 2: Wendt, B.J. and B.A. Wendt, B.J. and B.A. Reichert, “The Modelling of Reichert, “The Modelling of

Symmetric Airfoil Vortex Symmetric Airfoil Vortex Generators.” AIAA Paper 96-Generators.” AIAA Paper 96-

0807.0807.

History of Vortex History of Vortex GeneratorsGenerators First used in England (inventor First used in England (inventor

unknown)unknown) Used first on Transport Jets and Used first on Transport Jets and

BizjetsBizjets Used as a “band-aid” for localized Used as a “band-aid” for localized

mach buffeting problemsmach buffeting problems First GA applications on Cessna First GA applications on Cessna

206 and Baron D-55206 and Baron D-55

How They WorkHow They Work

Create strong tip vortices Create strong tip vortices which feed high energy air which feed high energy air from the external stream from the external stream to mix with/replace the to mix with/replace the slower moving air in the slower moving air in the boundary layerboundary layer

Reduces the effects of Reduces the effects of adverse pressure adverse pressure gradients and prevents gradients and prevents separationseparation

Ref. 3 http://home1.gte.net.pjbemail/VortexGen.html

Flow Effects of VGsFlow Effects of VGs

Ref. 4 www.avweb.com/news/reviews/182564-www.avweb.com/news/reviews/182564-1.html1.html

Shed Vortex StructureShed Vortex Structure

Ref. 5 Klausmeyer, Steven; Papadakis, Michael; and Lin, Klausmeyer, Steven; Papadakis, Michael; and Lin, John, “A Flow Physics Study of Vortex Generators on a John, “A Flow Physics Study of Vortex Generators on a Multi-element Airfoil.” AIAA Paper 96-0548Multi-element Airfoil.” AIAA Paper 96-0548

VG Effect on CVG Effect on CLL at at Various Angles of Various Angles of AttackAttack

Ref. 6 Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Generator Position and Orientation on Highly Swept Wings.” Generator Position and Orientation on Highly Swept Wings.”

AIAA-97-2319AIAA-97-2319

Arrangement of VGsArrangement of VGs

Usually located Usually located at the transition at the transition from laminar to from laminar to turbulent flowturbulent flow

Typically 80% of Typically 80% of boundary layer boundary layer thicknessthickness

Ref. 4 www.avweb.com/news/rewww.avweb.com/news/re

views/182564-1.htmlviews/182564-1.html

Various GA Aircraft Various GA Aircraft Models Which Offer VG Models Which Offer VG Kits Kits BEECHBEECH

Duke 60, A60, B60, Duke 60, A60, B60, Bonanza 33, 35, 36, 36TCBonanza 33, 35, 36, 36TC

CESSNACESSNA120/140120/140Skywagon 180, 185Skywagon 180, 185310, 310A-R, T310P-R310, 310A-R, T310P-R320D-F320D-F335, 340, 340A335, 340, 340A401, 401A, 401B401, 401A, 401B402, 402A, 402B, 402C402, 402A, 402B, 402C414, 414A414, 414A421, 421A, 421B, 421C421, 421A, 421B, 421C441 (Conquest II)441 (Conquest II)

deHAVILLANDdeHAVILLANDBeaver Mk IBeaver Mk I

Ref. 7 www.airliners.net/infowww.airliners.net/info

Various GA Aircraft Various GA Aircraft Models Which Offer VG Models Which Offer VG Kits (cont.)Kits (cont.) PIPERPIPER

Navajo PA31-310, 325C/RNavajo PA31-310, 325C/RColemill Panther I & IIColemill Panther I & IIChieftan PA31-350, T1020Chieftan PA31-350, T1020Seneca II/III/IV PA34Seneca II/III/IV PA34Super Cruiser PA12, PA14Super Cruiser PA12, PA14Super Cub PA18Super Cub PA18

AGPLANESAGPLANESAyres Thrush, Air Tractor,Ayres Thrush, Air Tractor,Cessna 188 AgWagon,Cessna 188 AgWagon,Piper PA36 Brave, Piper PA36 Brave, Dromader, Dromader, Weatherly Weatherly Ref. 7 www.airliners.net/infowww.airliners.net/info

Commercial Transport Commercial Transport Aircraft with VGsAircraft with VGs

Ref. 7 www.airliners.net/infowww.airliners.net/info

Pros and ConsPros and Cons

Pros:Pros:– Increases slope of Increases slope of

lift curvelift curve– Increase in Gross Increase in Gross

Take-off WeightTake-off Weight– Stall speed Stall speed

reduction (7-21%)reduction (7-21%)– Improved handling Improved handling

qualitiesqualities– Decrease tire and Decrease tire and

brake wearbrake wear

Cons:Cons:– ExpensiveExpensive– Makes debugging Makes debugging

of the leading edge of the leading edge difficultdifficult

– Possible source of Possible source of vibrationvibration

– Dual instruction Dual instruction and practice and practice required for full required for full effectivenesseffectiveness

More ProsMore Pros

Shorter take-offs and landings Shorter take-offs and landings Steeper climb-outs and Steeper climb-outs and

approachesapproaches Reduction of min control speedReduction of min control speed No extra dragNo extra drag No weight and balance changeNo weight and balance change No extra maintainenceNo extra maintainence

VGs are Everywhere!VGs are Everywhere!

Ref. 8 www.greenwoodcorvettes.netwww.greenwoodcorvettes.net

Go Faster StripGo Faster Strip

Ref. 3 http://home1.gte.net.pjbemail/VortexGen.htmlhttp://home1.gte.net.pjbemail/VortexGen.html

Head Mounted Vortex Head Mounted Vortex GeneratorsGenerators

Ref. 3 http://home1.gte.net.pjbemail/VortexGenhttp://home1.gte.net.pjbemail/VortexGen.html.html

ReferencesReferences

1.1. Clancy, L.J. “Aerodynamics.” Halsted Press, 1975. Clancy, L.J. “Aerodynamics.” Halsted Press, 1975. 2.2. Wendt, B.J. and B.A. Reichert, “The Modelling of Wendt, B.J. and B.A. Reichert, “The Modelling of

Symmetric Airfoil Vortex Generators.” AIAA Paper 96-Symmetric Airfoil Vortex Generators.” AIAA Paper 96-0807.0807.

3.3. http://home1.gte.net.pjbemail/VortexGen.htmlhttp://home1.gte.net.pjbemail/VortexGen.html4.4. www.avweb.com/news/reviews/182564-1.htmlwww.avweb.com/news/reviews/182564-1.html5.5. Klausmeyer, Steven; Papadakis, Michael; and Lin, John, “A Klausmeyer, Steven; Papadakis, Michael; and Lin, John, “A

Flow Physics Study of Vortex Generators on a Multi-Flow Physics Study of Vortex Generators on a Multi-element Airfoil.” AIAA Paper 96-0548element Airfoil.” AIAA Paper 96-0548

6.6. Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Broadley, Ian and Garry, Kevin, “Effectiveness of Vortex Generator Position and Orientation on Highly Swept Generator Position and Orientation on Highly Swept Wings.” AIAA-97-2319Wings.” AIAA-97-2319

7.7. www.airliners.net/infowww.airliners.net/info8.8. www.greenwoodcorvettes.netwww.greenwoodcorvettes.net

Animated vortex on title page taken from ref. 3Animated vortex on title page taken from ref. 3