The Design and Development of an Active Smart Wing Model

ATAK Technologies

Team StructureTeam Structure Thomas AyersThomas Ayers

Project LeaderProject Leader Robert AguirreRobert Aguirre

Senior Testing Research SpecialistSenior Testing Research Specialist Kevin MackenzieKevin Mackenzie

Senior Modeling and Design SpecialistSenior Modeling and Design Specialist Vu TranVu Tran

Senior Research SpecialistSenior Research Specialist Dr. R. O. StearmanDr. R. O. Stearman

University of Texas Faculty ConsultantUniversity of Texas Faculty Consultant

Presentation OverviewPresentation Overview

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Model Testing OptionsModel Testing Options Project AccomplishmentsProject Accomplishments Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

Project BackgroundProject Background ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Randall BoldingRandall BoldingWrote a master’s thesis in 1978 Wrote a master’s thesis in 1978 in which a wing model was used in which a wing model was used to research the use of a to research the use of a stabilator as an active control to stabilator as an active control to suppress fluttersuppress flutter

Lockheed Martin CorporationLockheed Martin CorporationA research project on the A research project on the benefits that an active wing can benefits that an active wing can provide in contemporary provide in contemporary aircraft designaircraft design

High Airspeed BenefitsHigh Airspeed Benefits ObjectivesObjectives TheoryTheory Model Model TestingTesting WorkWork SummarySummary QuestionsQuestions

At high airspeeds normally At high airspeeds normally latent aerodynamic forces latent aerodynamic forces become powerful enough to become powerful enough to affect the flow about the airfoilaffect the flow about the airfoil

These changes cause torsional These changes cause torsional moments on the wingmoments on the wing

Theoretically, the use of active Theoretically, the use of active wing control on the leading wing control on the leading edge flaps and ailerons can be edge flaps and ailerons can be used in order to better control used in order to better control these latent aerodynamic forcesthese latent aerodynamic forces

Low Airspeed BenefitsLow Airspeed Benefits ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

At low speeds airflow about At low speeds airflow about the wing can separate from the wing can separate from the wing causing a “stall”the wing causing a “stall”

In natural flight, resonant In natural flight, resonant flapping is used to sustain flapping is used to sustain flight at low flight speedsflight at low flight speeds

Theoretically, oscillating the Theoretically, oscillating the wings by using the control wings by using the control surfaces would create high surfaces would create high lift conditions for short, low lift conditions for short, low airspeed maneuversairspeed maneuvers

Project ObjectiveProject Objective ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

To create an active wing To create an active wing model for the purpose of model for the purpose of defining relationships defining relationships between control surface between control surface oscillation and flight oscillation and flight performanceperformance

Aerodynamic TheoryAerodynamic Theory

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Model Testing OptionsModel Testing Options Project AccomplishmentsProject Accomplishments Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

Desirable Flow TypesDesirable Flow Types BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Attached-flow: Difference of the circulations of the upper and lower boundary layers create a lift force near a quarter chord of the airfoil. (figure a)

Detached-vortex-flow: rolled-up leading edge vortices create additional lift. (figure b)

[4]

Problems EncounteredProblems Encountered BackgrounBackgroun

dd TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

When a critical angle of attack achieved to create high lift, separated unsteady flow is unavoidable, and the vortices formed become uncontrollable once they leave the body.

Unsteady separation

Vortex shedding

Vortex breakdown

Separation ControlSeparation Control BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

To control separation, essentially the boundary vorticity flux control, a relationship between pressure, inertial, and viscous forces must be utilized.

Methods for controlling separation:

1) Control tangential pressure gradient: proper design of airfoil and wing geometry

2) Control skin friction field: modify local skin friction field near critical points

3) Introduce local movable wall: oscillating flaps

Reattachment ControlReattachment Control BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

When the boundary layer is already When the boundary layer is already separated, control of its reattachment separated, control of its reattachment is also feasible by utilizing unsteady is also feasible by utilizing unsteady excitations.excitations.

Example: Small leading-edge oscillating flap was Example: Small leading-edge oscillating flap was used to forced the shear layer separated from a used to forced the shear layer separated from a sharp leading edge to attach to just the sharp leading edge to attach to just the upstream of a round trailing edge, hence upstream of a round trailing edge, hence captured a strong vortex above a two-captured a strong vortex above a two-dimensional airfoil with angle of attack up to 27 dimensional airfoil with angle of attack up to 27 degree. Lift was increased by 60%.degree. Lift was increased by 60%.

[4][4]

Reattachment ControlReattachment Control BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

The inviscid vortex method can be used to compare flow patterns with or without leading-edge oscillation

Case (a) : leading-edge vortex moves downstream as new vorticies start to form. The leading edge vortex cuts off the trailing edge vortex sheet. The main vortex will eventually shed.

Case (b): main vortex is stabilized and stays close to the wing with nearly uniform vorticity distribution

[4]

Reattachment ControlReattachment Control BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

An additional example:An additional example:

Poly Vinylidence Flouride (PVDF) piezoelectric film was Poly Vinylidence Flouride (PVDF) piezoelectric film was used on the surface of a NACA 0012 airfoil to used on the surface of a NACA 0012 airfoil to generate surface oscillation through polarization generate surface oscillation through polarization changes in the materialchanges in the material

[5][5]Non-oscillated case: Max lift coefficient = 0.72, stall angle = 14 degreeNon-oscillated case: Max lift coefficient = 0.72, stall angle = 14 degree

Oscillated case: Max lift coefficient = 0.76, stall angle = 15 degreeOscillated case: Max lift coefficient = 0.76, stall angle = 15 degree

[5][5] [5] [5]

maxLC maxLC

Reattachment ControlReattachment Control BackgrounBackgroun

dd TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

For a highly swept wing, unsteady surface For a highly swept wing, unsteady surface excitations focus on delaying vortex excitations focus on delaying vortex breakdown, or can be used to maintain highly breakdown, or can be used to maintain highly concentrated and stable leading-edge vorticesconcentrated and stable leading-edge vortices

Schematic of mini-upper wing Schematic of mini-upper wing

[4][4]

Reattachment ControlReattachment Control BackgroundBackground TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Mini-upper Wing:Mini-upper Wing:

The wing has a larger incidence The wing has a larger incidence than the main wing, thus than the main wing, thus forcing the flow below it to forcing the flow below it to converge. This implies an converge. This implies an additional axial acceleration at additional axial acceleration at the vortex core, and therefore the vortex core, and therefore delays its burst. However, the delays its burst. However, the applicable angle of attack is applicable angle of attack is limited, due to limitations limited, due to limitations created by the wing designcreated by the wing design

Model DesignModel Design

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Model Testing OptionsModel Testing Options Accumulated Project WorkAccumulated Project Work Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

Actuator DesignsActuator Designs BackgroundBackground TheoryTheory ModelModel WorkWork SummarySummary QuestionsQuestions

Hydraulic ActuatorHydraulic Actuator

Electromechanical Electromechanical ActuatorActuator

Electric MotorElectric Motor

Benefits of ATAK’s Benefits of ATAK’s DesignDesign

ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Size of Control SystemSize of Control System – Electric – Electric motor and shaft will be half the size of the previous groups

Ease of Operation – Does not require understanding of complex controller

Able to Test – By taking wind tunnel dimensions into account when designing we make sure that we will be able to mount the wing in order to obtain Cl and Cd measurements

Flexibility – Leading and trailing edge flaps will be able to oscillate. Will be able to control angle of deflection and phase between flaps

Model DesignModel Design

Overall Model Assembly

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Wing Spar, Engine and Rods

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Gearing Assembly

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Bevel Gears

ObjectiveObjectivess

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Model DesignModel Design

Actuation System – Push/Pull Rods

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Actuation System including Control Surfaces

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Wing Model Without Modified Control Surfaces

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Wing Model With Deflected Control Surfaces

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model DesignModel Design

Overall Model Assembly

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Model Testing OptionsModel Testing Options

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Model Testing OptionsModel Testing Options Accumulated Project WorkAccumulated Project Work Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

BackgroBackgroundund

TheoryTheory ModelModel TestingTesting WorkWork SummarSummar

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Model Testing GoalsModel Testing Goals

Take next step in project Take next step in project developmentdevelopment

Obtain and reduce dataObtain and reduce data

Conduct repeated tests to ensure Conduct repeated tests to ensure quality data acquiredquality data acquired

Testing Data AcquisitionTesting Data Acquisition BackgroBackgro

undund TheoryTheory ModelModel TestingTesting WorkWork SummarSummar

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Relationship between oscillation Relationship between oscillation frequency and frequency and Variations of coefficient of liftVariations of coefficient of lift Pressure distributions over wingPressure distributions over wing Wing spar strainWing spar strain Wing tip flutterWing tip flutter

Relationships can be used to find Relationships can be used to find optimum frequencies foroptimum frequencies for Maximizing coefficient of liftMaximizing coefficient of lift Minimizing wing spar strainMinimizing wing spar strain Minimizing wing tip flutterMinimizing wing tip flutter

Model Testing Model Testing EquipmentEquipment

BackgroBackgroundund

TheoryTheory ModelModel TestingTesting WorkWork QuestionQuestion

ss SummarSummar

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Smoke wireSmoke wire

Pressure tapsPressure taps

Strain GaugesStrain Gauges

Accelerometer Accelerometer

Model Testing Model Testing SuggestionsSuggestions

BackgroBackgroundund

TheoryTheory ModelModel TestingTesting WorkWork SummarSummar

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Modify model as neededModify model as needed

Start testing as soon as possibleStart testing as soon as possible

Be familiar with theory and Be familiar with theory and equations needed to reduce dataequations needed to reduce data

Project AccomplishmentsProject Accomplishments

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Optional Testing ProceduresOptional Testing Procedures Project AccomplishmentsProject Accomplishments Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

Project AccomplishmentsProject Accomplishments ObjectiveObjective

ss TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Project has been advanced over Project has been advanced over the past four termsthe past four terms

The Active Wing Group (AWG)The Active Wing Group (AWG)

Active Wing Technology (AWT)Active Wing Technology (AWT)

Active Wing Engineering (AWE)Active Wing Engineering (AWE)

ATAK Technologies (ATAK)ATAK Technologies (ATAK)

Active Wing GroupActive Wing Group ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Recovered F-111 wing-tail Recovered F-111 wing-tail from storagefrom storage

Investigated limit cycle Investigated limit cycle oscillations (LCO)oscillations (LCO)

Provided a strong foundation Provided a strong foundation for Summer 2002 project for Summer 2002 project continuationcontinuation

Active Wing Active Wing TechnologiesTechnologies

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarSummar

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Primarily Research on F-111Primarily Research on F-111

Limit cycle oscillations (LCO)Limit cycle oscillations (LCO)

Increasing lift on fighter Increasing lift on fighter wingswings

Implementation of control Implementation of control surfacessurfaces

Digital and analog control Digital and analog control systemssystems

Researched the aerodynamic Researched the aerodynamic theory behind oscillating flapstheory behind oscillating flaps

Selected actuation systemSelected actuation system

Constructed model wing with Constructed model wing with leading edge flapsleading edge flaps

ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Active Wing EngineeringActive Wing Engineering

ATAK TechnologiesATAK Technologies ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

ResearchResearchAerodynamic forces involved in active wing Aerodynamic forces involved in active wing

technologytechnologyControl surface effect on liftControl surface effect on lift

Model DesignModel DesignActuation systemActuation systemStructure designStructure designAutoCAD model AutoCAD model

Delivered spar design to machinist Delivered spar design to machinist for constructionfor construction

Gathered all necessary model Gathered all necessary model materials.materials.

Lab MaintenanceLab MaintenanceWorked to clean WRW 316Worked to clean WRW 316

ATAK TechnologiesATAK Technologies

Wing Structure

ObjectiveObjectivess

TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionQuestion

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Recommended Future Recommended Future PursuitsPursuits

Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Model DesignModel Design Optional Testing ProceduresOptional Testing Procedures Project AccomplishmentsProject Accomplishments Recommended Future PursuitsRecommended Future Pursuits SummarySummary QuestionsQuestions

Recommended Future Recommended Future PursuitsPursuits

ObjectivesObjectives TheoryTheory ModelModel TestingTesting WorkWork SummarySummary QuestionsQuestions

Complete the construction of the Complete the construction of the wing modelwing model

Prepare for experimentation using Prepare for experimentation using the modelthe model Design testing equipment and conditionsDesign testing equipment and conditions Place instruments on model designPlace instruments on model design Use LabView software to coordinate Use LabView software to coordinate

data acquisitiondata acquisition Conduct experiments using wing Conduct experiments using wing

modelmodel Reduce acquired data and draw Reduce acquired data and draw

conclusions concerning the conclusions concerning the relationship between frequencies relationship between frequencies and the desired characteristics.and the desired characteristics.

Presentation SummaryPresentation Summary

Background InformationBackground Information Project ObjectivesProject Objectives Aerodynamic TheoryAerodynamic Theory Modeling and Final DesignModeling and Final Design Proposed Testing ProceduresProposed Testing Procedures Project AccomplishmentsProject Accomplishments Recommended Future WorkRecommended Future Work

ReferencesReferences[1][1] Aguirre, Robert, Thomas Ayers, Kevin Aguirre, Robert, Thomas Ayers, Kevin Mackenzie, Mackenzie,

and Vu Tran. “Design and Development of an Active Wing and Vu Tran. “Design and Development of an Active Wing Model.” ATAK Technologies, Austin, TX, Mar. 2003.Model.” ATAK Technologies, Austin, TX, Mar. 2003.

[2][2] Garret, Carlos, Justin Gray, and Kevin Garret, Carlos, Justin Gray, and Kevin Marr. Marr. “Design of an Active Controlled Wing Model Using Flap “Design of an Active Controlled Wing Model Using Flap Oscillation.” AWE Engineering, Austin, TX, Dec. 2002.Oscillation.” AWE Engineering, Austin, TX, Dec. 2002.

[3][3] Fuentes, David, Basil Philips, and Naoki Sato. “Design Fuentes, David, Basil Philips, and Naoki Sato. “Design and Control Modeling of an Active Variable Geometry Wing.” and Control Modeling of an Active Variable Geometry Wing.” Active Wing Technologies, Austin, TX, Aug. 2003.Active Wing Technologies, Austin, TX, Aug. 2003.

[4] Wu, J.M., Wu, J.Z., “Vortex Lift at a Very High Angle of Attack [4] Wu, J.M., Wu, J.Z., “Vortex Lift at a Very High Angle of Attack with Massively Separated Unsteady Flow,” with Massively Separated Unsteady Flow,” Fluid Dynamics of Fluid Dynamics of High Angle of AttackHigh Angle of Attack, R. Kawamura, Y. Aihara ed., Springer-, R. Kawamura, Y. Aihara ed., Springer-Verlag, Berlin Heidelberg, 1993, pp. 35-63.Verlag, Berlin Heidelberg, 1993, pp. 35-63.

[5] Kobayakawa, M., Kondo, Y., Suzuki, H., “Airfoil Flow Control [5] Kobayakawa, M., Kondo, Y., Suzuki, H., “Airfoil Flow Control at High Angle of Attack by Surface Oscillation,” at High Angle of Attack by Surface Oscillation,” Fluid Fluid Dynamics of High Angle of AttackDynamics of High Angle of Attack, R. Kawamura, Y. Aihara , R. Kawamura, Y. Aihara ed., Springer-Verlag, Berlin Heidelberg, 1993, pp. 265-273.ed., Springer-Verlag, Berlin Heidelberg, 1993, pp. 265-273.

Questions?