Virginia Tech AE/ME Morphing Wing Project

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Virginia Tech AE/ME Morphing Wing Project

• Midterm Presentation

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Team Members
AE Members Laura Arrison Kevin Birocco Chuck
Gaylord Brandon Herndon Kathleen Manion Mike
Metheny Chris Johnston (Grad Student)
ME Members Michael Cummins Robert
Forrester Nicholas Hanak Tae Kwon Mathew
McCarty Marcus Tepaske David Neal (Grad
Student) Leonard Wiggins (Grad Student)
Sophomore Members Caroline Hutchinson (ME) Greg
Wargo (EE)
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Presentation Outline

• RFP, Project Goals, Mission Drivers
• Overview of last years progress
• Comparison model selection / building
• Instrumentation for analysis
• This years ideas technology required
• Budget
• Timeline

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DARPA?

• 200 change in AR
• 50 change in area
• 20 change in sweep
• 50 change in twist

Although too ambitious for our time and budget
constraints to fit into our team-determined RFP,
it is interesting to look at some of the specs
industry is aiming for. Photo and DARPA specs
courtesy Aviation Now Online, http//www.aviationn
ow.com/content/ncof/ncf_n66.htm
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Request for Proposal (RFP)

• Design a full flying delta wing with morphing
  capability to provide a comparison to a
  conventionally controlled full flying delta wing
  aircraft.

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How to accomplish RFP

• Purchase and build an existing radio controlled
  conventional flying delta wing
• Instrument kit plane to record flight data
• Fly the model to obtain data
• Design and build a full flying morphing delta
  wing
• Instrument the morphing aircraft
• Fly morphing wing and record flight data
• Compare data from the two delta wings

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Project Goals

• Build on what was learned last year
• Successfully design, build, and fly a morphing
  delta wing
• Analyze flight results from each plane and
  compare find out what worked, what didnt and
  most importantly why

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Mission Drivers

• Feasibility
• Complexity
• Number of designs
• Building / tweaking time needed
• Cost
• Uncertain budget
• Use of advanced materials unlikely

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Mission Drivers (cont.)

• Time
• Keep design as simple as possible while still
  meeting RFP
• More time needs to be spent testing rather than
  tweaking and making things work
• Eye on the prize fly a morphing aircraft

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Last year. . .

• Three morphing concepts were developed
  servo-driven, piezo-electric, shape-memory alloy
• Models were tested in the wind tunnel but not
  actually flown

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Choosing a comparison plane Selection Criteria

• Delta wing planform
• 4 foot wingspan
• Ample interior volume for instrumentation
• Gas engine preferred

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Kit Plane Selection FOM
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The Winner Delta Vortex

• 54 wingspan
• 47 long
• 1375 in2 surface area
• 7.5 to 8.5 lbs

Photo and specs from http//www.atsrcplanes.com/vo
rtex.htm
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Building the kit

• Purchased kit and supplemental materials
• Cut out individual pieces from balsa and ply
• Attached ribs with a spar near the quarter-chord
  line
• Balsa sheeting applied
• Servo mounts and engine box constructed

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Building, continued

• Create instrumentation bay
• Modify kit to include a removable hatch for easy
  instrument access
• Made vertical tails and cut out holes to insert
  into top sheeting
• Covered plane in Monokote

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Instrumentation what we wanted to measure
Cruise/Trim Data
Performance Data

• Airspeed
• Altitude
• Control surface deflections/forces
• Angle of attack

• Lift coefficient
• Drag coefficient
• Accelerations
• Body rates

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What we actually will measure
Cruise/Trim Data
Performance Data

• Airspeed
• Control surface deflections/forces

• Lift coefficient
• Accelerations
• Body rates

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Instruments Needed

• Pitot tube airspeed
• Accelerometers body forces
• Gyros body angular rates
• Servos
• Control surface deflections (via servo duty
  cycle)
• Control surface forces (via servo feedback)

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Accuracy Requirements

• Measured quantities (accelerations, body rates)
  with lt 5 error
• Calculated quantities (lift coefficient,
  airspeed) with lt 10 error
• must perform uncertainty estimates to determine
  expected error
• selected reference condition 66 fps _at_ 2000 ft

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Uncertainty Estimations Lift Coefficient
CL 0.52 d(CL) 0.039 error 7.4
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Uncertainty Estimations Velocity
V 66.0 fps d(V) 1.7 fps error
2.3
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Final Instrumentation Decisions

• Crossbow AD2000 Data Logger
• Crossbow CXL-10LP3 Triple Axis Accelerometer
• Hobbico Multi-Purpose Micro Piezo Gyro
• Dwyer Standard Model 1/8 pitot tube along with
  Dwyer Differential Pressure Transducer

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Crossbow AD2000 Data Logger

• Input voltage 0-5 V
• Resolution 20 mV
• Sampling frequency (Hz) Fast as 500, slow as 99
  min.
• Date storage 1 MB
• Power supply 8-35 V

• Battery life (Lithium) up to 6 months
• Operating temperature (C) -10 to 60
• Download rate 9600 to 115.2 Kbps
• Physical dimensions 5.8 x 3.6 x 1.3
• Weight 8 oz.

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Crossbow AD2000 (cont.)

• Plotting features enable immediate analysis and
  presentation quality graph creation. This comes
  complete with scroll, zoom, scale, annotate, 2D,
  3D, and other capabilities
• Can withstand forces of several hundred gs,
  highly durable, designed to be able to be used in
  spacecraft applications

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Crossbow 3-Axis Accelerometer

• Measurement range 10g
• Output 0-5 volts
• Error 5
• Dimensions 1 in3
• Weight 1.5 oz.

http//www.xbow.com/Products/Accelerometers.htm
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Hobbico Multi-Purpose Micro Piezo Gyro

• Originally designed for use in stabilizing model
  aircraft and helicopters.
• Dimensions 1.1" x 1.1" x 0.6"
• Weight 0.49 oz
• This was a much cheaper (and smaller) alternative
  than the other gyro systems out there.
• We determined that we could use the internal
  outputs of the gyro to determine angular rates on
  our airplane.

http//www.hobbico.com/accys/hcam4000.html
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Hobbico Gyro (cont.)

• The response time was very fast, but not known,
  due to the lack of willingness by the products
  company to comply with us.
• They claimed that their product could not be used
  in this manner and they would not assist us
  further.
• Three gyros are likely to be used, one for each
  axis of rotation.

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Dwyer Standard Model 1/8 Pitot Tube

• No calibration needed
• Made from stainless steel w/ silver solder for
  leak-proof measurements
• Operates up to 800F
• Available with mounting flanges and comes in
  either 6 or 12 lengths

http//www.dwyer-inst.com/htdocs/
airvelocity/160.html
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Dwyer Differential Pressure Transducer

• Attaches directly to pitot tube and converts the
  dynamic pressure data into a voltage signal that
  can be read.
• Reads up to 5in of water (dynamic pressure)
• Error 2.1
• 4.75 to 8V needed to operate (provided by data
  logger)
• Operating temperature 10 to 60C

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Dwyer Pressure Transducer (cont.)

• Response time of 15msec
• Weight 2.5 oz
• Dimensions 2.5 x 1 x 2.8

http//www.dwyer-inst.com/htdocs/PRESSURE/qsseries
668.cfm
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Current Status of Instrumentation

• Data Logger ordered, awaiting arrival
• 3-Axis Accelerometer Obtained already, unable
  to test until data logger arrives
• Gyro Obtained 1 already, working on calibrating
  the output voltages of the gyro, as no specs are
  given. Also will have to scale the voltage
  output of the gyro (currently around 135mV) to
  send to the data logger.

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Instrumentation Status (cont.)

• Pitot tube and Pressure transducer. Ordered as
  of last week, awaiting arrival. Need to determine
  how to connect it to the data logger (should not
  be a problem because the output voltages are
  already in the correct range of 0-5V)

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What about Morphing?
Mission Morphing
Control Morphing

• AR change
• Sweep change
• Area change
• Dihedral / anhedral change

• Camber change
• Twist change
• Continuous, blended control surfaces

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Piezo-electric Control Morphing

• Layered strips that bend upon application of
  voltage
• Fine degree of control but power required may be
  a limiting factor

http//www.face-int.com/thunder/prod/tprod.htm
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Servo-driven Control Morphing

• Multiple mechanical linkages on trailing edge
  ribs
• Servo-actuated
• Flexible skin creates continuous morph

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Telescoping Wing

• Allows for additional wingspan better for
  landing and low-speed cruise
• Retract for increased maneuverability

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Telescoping, Continued
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Integral Actuation Morphing

• Smart Materials sandwiched between fiberglass
  layers
• Continuous control surface morphing
• Cost?

www.intellimat.com/materials/applications/active_h
elicopter_rotor_blades.html
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Important Flexible skin

• Shape-memory alloys often heat-activated so
  slow to respond
• Latex derivatives a possibility for model
  aircraft impractical for full size aircraft
• Electric current driven solutions often
  power-hungry
• Composite smart materials expensive, currently
  unproven

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Whats Next?

• Continue to research feasibility of concepts
• Narrow down to one concept, with a backup plan if
  time becomes short and/or materials become
  problematic

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Budget

• Budget is not well-defined
• Problems
• Must meet goals with limited funds
• Must budget funds for next semester
• Must be inventive to get more money

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Budget is Dependant On

• Mechanical Engineering Department
• Originality of Designs
• Ability to Meet goals
• Sponsorship

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Expenses

• Delta Vortex Kit 88.50
• Plane Expenses 932.92
• Instrumentation 1695.00
• Total To Date 2716.42
• Morphing Aircraft (1 or 2) ??
• Crashed Aircraft ??

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Availability to Increase Budget

• Use of Intelligent Materials
• Ability to compare energy required to control the
  aircraft (Conventional vs. Morphing)
• Additional sponsorship

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Time Line

• By December 2002
• Have built and flown Delta Vortex
• Have flight data from Delta Vortex
• Begin Design of Morphing Aircraft
• Begin Construction and testing of Morphing
  Aircraft

• By April 2003
• Have flying Morphing RC Aircraft
• Have flight data from Morphing Aircraft
• Have conclusions and presentation ready for NASA
  Langley

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Conclusion

• In order to meet our RFP goals, we must
  design, build, and fly a morphing RC aircraft and
  compare its flight data to that of a conventional
  delta wing RC aircraft. This will be
  accomplished by building on last years project,
  studying morphing concepts and new technologies,
  the use of instrumentation, and being efficient
  with our budget.

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Thank You

• Questions/Comments/Complaints?