Transcript The Design and Development of an Active Smart Wing Model

The Design and Development of
an Active Smart Wing Model
ATAK Technologies
Team Structure
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Thomas Ayers
Project Leader
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Robert Aguirre
Senior Testing Research Specialist
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Kevin Mackenzie
Senior Modeling and Design Specialist
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Vu Tran
Senior Research Specialist
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Dr. R. O. Stearman
University of Texas Faculty Consultant
Presentation Overview
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Project Objectives
Aerodynamic Theory
Model Design
Model Testing Options
Project Accomplishments
Recommended Future Pursuits
Summary
Questions
Project Background
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Objectives
Theory
Model
Testing
Work
Summary
Questions
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Randall Bolding
Wrote a master’s thesis in 1978 in which a
wing model was used to research the use
of a stabilator as an active control to
suppress flutter
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Lockheed Martin Corporation
A research project on the benefits that an
active wing can provide in contemporary
aircraft design
High Airspeed Benefits
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Objectives
Theory
Model
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Summary
Questions
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At high airspeeds normally latent
aerodynamic forces become powerful
enough to affect the flow about the
airfoil
These changes cause torsional
moments on the wing
Theoretically, the use of active wing
control on the leading edge flaps and
ailerons can be used in order to better
control these latent aerodynamic forces
Low Airspeed Benefits
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Objectives
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Summary
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At low speeds airflow about the wing
can separate from the wing causing a
“stall”
In natural flight, resonant flapping is
used to sustain flight at low flight
speeds
Theoretically, oscillating the wings by
using the control surfaces would create
high lift conditions for short, low
airspeed maneuvers
Project Objective
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Objectives
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Model
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Summary
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To create an active wing model for the
purpose of defining relationships
between control surface oscillation
and flight performance
Aerodynamic Theory
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Project Objectives
Aerodynamic Theory
Model Design
Model Testing Options
Project Accomplishments
Recommended Future Pursuits
Summary
Questions
Desirable Flow Types
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Background
Theory
Model
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Work
Summary
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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 Encountered
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Background
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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 Control
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Background
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Model
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Summary
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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 Control
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Background
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When the boundary layer is already separated,
control of its reattachment is also feasible by
utilizing unsteady excitations.
Example: Small leading-edge oscillating flap was used to forced
the shear layer separated from a sharp leading edge to attach
to just the upstream of a round trailing edge, hence captured
a strong vortex above a two-dimensional airfoil with angle of
attack up to 27 degree. Lift was increased by 60%.
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Reattachment Control
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Background
Theory
Model
Testing
Work
Summary
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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
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CL max
Reattachment Control
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Background
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Model
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Summary
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An additional example:
Poly Vinylidence Flouride (PVDF) piezoelectric film was used on the
surface of a NACA 0012 airfoil to generate surface oscillation
through polarization changes in the material
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Non-oscillated case: Max lift coefficient = 0.72, stall angle = 14 degree
Oscillated case: Max lift coefficient = 0.76, stall angle = 15 degree
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Reattachment Control
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Background
Theory
Model
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Work
Summary
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For a highly swept wing, unsteady surface excitations focus
on delaying vortex breakdown, or can be used to maintain
highly concentrated and stable leading-edge vortices
Schematic of mini-upper wing
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Reattachment Control
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Background
Theory
Model
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Work
Summary
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Mini-upper Wing:
The wing has a larger incidence than the
main wing, thus forcing the flow below
it to converge. This implies an
additional axial acceleration at the vortex
core, and therefore delays its burst.
However, the applicable angle of attack
is limited, due to limitations created by
the wing design
Model Design
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Project Objectives
Aerodynamic Theory
Model Design
Model Testing Options
Accumulated Project Work
Recommended Future Pursuits
Summary
Questions
Actuator Designs
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Background
Theory
Model
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Summary
Questions
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Hydraulic Actuator
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Electromechanical
Actuator
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Electric Motor
Benefits of ATAK’s Design
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Objectives
Theory
Model
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Summary
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Size of Control System – 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 Design
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Objectives
Theory
Model
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Summary
Questions
Overall Model Assembly
Model Design
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Objectives
Theory
Model
Testing
Work
Summary
Questions
Wing Spar, Engine and Rods
Model Design
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Objectives
Theory
Model
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Work
Summary
Questions
Gearing Assembly
Model Design
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Objectives
Theory
Model
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Work
Summary
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Bevel Gears
Model Design
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Objectives
Theory
Model
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Work
Summary
Questions
Actuation System – Push/Pull Rods
Model Design
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Objectives
Theory
Model
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Work
Summary
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Actuation System including Control Surfaces
Model Design
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Objectives
Theory
Model
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Work
Summary
Questions
Wing Model Without Modified Control Surfaces
Model Design
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Objectives
Theory
Model
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Work
Summary
Questions
Wing Model With Deflected Control Surfaces
Model Design
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Objectives
Theory
Model
Testing
Work
Summary
Questions
Overall Model Assembly
Model Testing Options
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Project Objectives
Aerodynamic Theory
Model Design
Model Testing Options
Accumulated Project Work
Recommended Future Pursuits
Summary
Questions
Model Testing Goals
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Background
Theory
Model
Testing
Work
Summary
Questions
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Take next step in project development
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Obtain and reduce data
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Conduct repeated tests to ensure quality data
acquired
Testing Data Acquisition
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Background
Theory
Model
Testing
Work
Summary
Questions
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Relationship between oscillation frequency
and
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Variations of coefficient of lift
Pressure distributions over wing
Wing spar strain
Wing tip flutter
Relationships can be used to find optimum
frequencies for
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Maximizing coefficient of lift
Minimizing wing spar strain
Minimizing wing tip flutter
Model Testing Equipment
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Background
Theory
Model
Testing
Work
Questions
Summary
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Smoke wire
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Pressure taps
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Strain Gauges
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Accelerometer
Model Testing Suggestions
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Background
Theory
Model
Testing
Work
Summary
Questions
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Modify model as needed
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Start testing as soon as possible
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Be familiar with theory and equations needed
to reduce data
Project Accomplishments
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Project Objectives
Aerodynamic Theory
Model Design
Optional Testing Procedures
Project Accomplishments
Recommended Future Pursuits
Summary
Questions
Project Accomplishments
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Objectives
Theory
Model
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Work
Summary
Questions
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Project has been advanced over the past four
terms
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The Active Wing Group (AWG)
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Active Wing Technology (AWT)
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Active Wing Engineering (AWE)
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ATAK Technologies (ATAK)
Active Wing Group
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Objectives
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Model
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Summary
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Recovered F-111 wing-tail from
storage
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Investigated limit cycle oscillations
(LCO)
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Provided a strong foundation for
Summer 2002 project continuation
Active Wing Technologies
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Objectives
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Summary
Questions
Primarily Research on F-111
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Limit cycle oscillations (LCO)
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Increasing lift on fighter wings
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Implementation of control surfaces
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Digital and analog control systems
Active Wing Engineering
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Objectives
Theory
Model
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Work
Summary
Questions
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Researched the aerodynamic theory
behind oscillating flaps
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Selected actuation system
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Constructed model wing with leading
edge flaps
ATAK Technologies
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Objectives
Theory
Model
Testing
Work
Summary
Questions
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Research
Aerodynamic forces involved in active wing
technology
Control surface effect on lift
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Model Design
Actuation system
Structure design
AutoCAD model
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Delivered spar design to machinist for
construction
Gathered all necessary model materials.
Lab Maintenance
Worked to clean WRW 316
ATAK Technologies
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Objectives
Theory
Model
Testing
Work
Summary
Questions
Wing Structure
Recommended Future Pursuits
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Project Objectives
Aerodynamic Theory
Model Design
Optional Testing Procedures
Project Accomplishments
Recommended Future Pursuits
Summary
Questions
Recommended Future Pursuits
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Objectives
Theory
Model
Testing
Work
Summary
Questions
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Complete the construction of the wing
model
Prepare for experimentation using the
model
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Design testing equipment and conditions
Place instruments on model design
Use LabView software to coordinate data
acquisition
Conduct experiments using wing model
Reduce acquired data and draw conclusions
concerning the relationship between
frequencies and the desired characteristics.
Presentation Summary
Background Information
 Project Objectives
 Aerodynamic Theory
 Modeling and Final Design
 Proposed Testing Procedures
 Project Accomplishments
 Recommended Future Work
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References
[1] Aguirre, Robert, Thomas Ayers, Kevin
Mackenzie, and Vu Tran. “Design
and Development of an Active Wing Model.” ATAK Technologies, Austin,
TX, Mar. 2003.
[2] Garret, Carlos, Justin Gray, and Kevin
Marr. “Design of an Active
Controlled Wing Model Using Flap Oscillation.” AWE Engineering, Austin,
TX, Dec. 2002.
[3] Fuentes, David, Basil Philips, and Naoki Sato. “Design and Control Modeling
of an Active Variable Geometry Wing.” Active Wing Technologies, Austin,
TX, Aug. 2003.
[4] Wu, J.M., Wu, J.Z., “Vortex Lift at a Very High Angle of Attack with
Massively Separated Unsteady Flow,” Fluid Dynamics of High Angle of Attack, R.
Kawamura, Y. Aihara ed., Springer-Verlag, Berlin Heidelberg, 1993, pp. 35-63.
[5] Kobayakawa, M., Kondo, Y., Suzuki, H., “Airfoil Flow Control at High Angle
of Attack by Surface Oscillation,” Fluid Dynamics of High Angle of Attack, R.
Kawamura, Y. Aihara ed., Springer-Verlag, Berlin Heidelberg, 1993, pp. 265273.
Questions?