Noah Heulitt Charlie Hanna Andrew Guion

Jinho Kim Dr. Parsaoran Hutapea

Temple University

Fly-by-Heat Smart Wing

Outline

I. Introduction & Material Background

II. Design Process

III. Design Process

IV. Results

What is a Shape Memory Alloy?

A deformed SMA spring will return to its high-temperature austenitic shape when

heated

Original Austenitic Shape

Twinned Martensitic

Form

Stressed Detwinned Martensitic Shape

Unstressed Austenitic Shape with Residual Strains

Hysteresis of Shape Memory Alloys

Hysteresis of shape memory alloys refers to slowed reaction times following high-cycle use.

Hysteresis is of less concern in the one-way shape memory effect.

Pseudoelastic response of NiTi wire specimen (Af=65°C) during the first 20 cycles T=70°C. After the first few cycles the hysteresis of the material stabilizes (kumar et al., 2003).

Design Objective

To create an airfoil with flaps controlled by shape memory alloy actuation

Potential Design Advantages

!  SMA actuation can be lightweight and adjustable-force

!  Low maintenance, low cost design

!  Applicable to additional aircraft flap control systems

Design Process

!  Research (SMA spring training and critical force experiments, ANSYS modeling) !  Manufacturing & Assembly - fabricating wing box and airfoil profiles - attaching SMA springs - wiring electrical circuit - adhering the wing skin !  Testing and Analysis

SMA Training

The shape memory training process requires the deformation of the material

followed by cyclic heating and quenching for 25-30 cycles

Spring Critical Force Experimentation and Analysis

ANSYS Modeling Model 2D geometry

Input material properties,

Apply voltage

heat transfer coefficient from theoretical calculations, and thermal expansion coefficient from experimental data

Apply boundary conditions

Analyze force generation and spring displacement

Manufacturing

Cutting airfoil profiles and wing box using the CNC router

Assembly Assembling the wing structure included - interlocking airfoil profiles to trusses - attaching the rotating flap tube

Assembly (cont.)

Wiring NiTi springs in parallel configuration

Assembly (cont.)

Wiring NiTi springs in series configuration

Assembly (cont.)

Covering the wing with clear plastic laminate skin

Testing

Application of current through springs to cause flap displacement

Top springs activated Bottom springs activated

Wind Tunnel Testing

Neutral position

Flap down

Flap up Heating Top springs

Wind Tunnel Testing

Heating Bottom Springs

Temperature Analysis

V 1.7 volts

R 0.5 ohm

T∞ 25 ˚C

h 35 W/m2K

HEATING

COOLING

EXPERIMENT CALCULATION

Surface Temperature

5s

Thermal inertia HEATING COOLING

HEATING COOLING

Surface Temperature

Estimated Flight Trajectory

α=10°

Force Analysis During Flight of Prototype

F max ≈ 26N

Pressure Distribution of Prototype

INSTANT BEFORE TAKE-OFF (38 m/s )

INSTANT BEFORE CRUISING (60 m/s)

AF=25%

AF=19%

Required Force INSTANT BEFORE TAKE-OFF (38 m/s )

INSTANT BEFORE CRUISING (60 m/s)

Force Generated by Flap Actuation

10 cm0 cm

6.4 N

V 3.94 volts

R 0.5 ohm

T∞ 1 ˚C

h 100.23 W/m2K

Temperature Prediction

V 5.0 volts

R 0.5 ohm

T∞ 1 ˚C

h 100.23 W/m2K

Slow Heating

Fast Heating

at Operation Altitude (2100 m)

Conclusion The developed design shows strong potential

for future aerospace applications following further refinement and testing under different

conditions.

Acknowledgments

!  Mr. Ren, lab administrator !  Leo Luo, graduate student