Undergraduate Laboratories in Aerospace Engineering · PDF file– AE 460: Aerodynamics & Propulsion Lab. ... 1-5 0 5 10 15 20 ... Airfoil Lift and Surface Pressure Cylinder wake,

Undergraduate Laboratories in AerospaceEngineering for Discovery, Diagnostics, and Theory

Greg ElliottDepartment of Aerospace Engineering

2UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGNDEPARTMENT OF AEROSPACE ENGINEERING

Outline

• Aerospace Engineering at UIUC• Laboratory Curriculum• Discovery Course Laboratories• Diagnostics, Theory and Design• Lessons Learned• Conclusions


AE Laboratory Curriculum

• Discovery Course: AE 100 (Freshman)Objective: Introduce students to aspects of aerospace engineering giving them hands-on problem solving design and data collection experience.

– Spacecraft and Rocket Section– Aircraft Design Section

• Upper Level AE Laboratory CoursesObjective: Typical Junior/Senior lab to introduce students to experimental methodologies, techniques, diagnostics, and confirmation of theories taught as part of the AE undergraduate curriculum.

– AE 360: Structures & Controls Lab– AE 460: Aerodynamics & Propulsion Lab


AE 100: Intro to Aerospace Engineering

• History of Aircraft Design • Case Study of Vehicle Development• Aircraft/Flight Theory and Design• Engineering Ethics• Hands-on Experiences

– Discovery Flights

– Radio Control Flying and Aircraft Performance– R/C Glider Design Project

Piper Archer III UIUC Institute of Aviation


R/C Flying and Aircraft Performance

• Student R/C Flying Experience (CCRCC-AMA)

• Instrumented R/C Aircraft Performance

Description: Students have the opportunity to pilot a 4-channel R/C trainer with hobbyists from the local R/C flying club. Students learn about basic flight maneuvers and aircraft control.

Description: Students collected data from instrumented R/C aircraft with on-board imaging data recording and telemetry for class examples and home-work problems.


Instrumented R/C Aircraft Flight Testing

• Engine Temperature

• Current / Voltage

• Telemetry

• Servo Positions

• Angle of Attack

Eagle Tree Systems• GPS

• Altimeter

• Pitot/Static Pressure

• x / y Accelerometer

• Optical RPM GPS

DataRecorder

Telemetry

X / YAccelerometer

Angle ofAttack

Pitot/Static Probe


Instrumented R/C Aircraft Flight Testing

R/C Aircraft – Eagle Tree Systems Airspeed and Rate of Climb

Lift, Drag and Control Surfaces

• Engine Temperature

• Current/Voltage

• Telemetry

• Servo Positions

• Angle of Attack

Eagle Tree Systems• GPS

• Altimeter

• Pitot/Static Pressure

• x / y Accelerometer

• Optical RPM

GPS

Pitot/Static Probe

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

-5 0 5 10 15 20

Angle of Attack [Deg]

Coe

ffici

ent o

f Lift

No FlapsFlaps Extended

Linear (No Flaps)

Linear (Flaps Extended)

-600

-400

-200

0

200

400

600

100 150 200 250 300 350Time Stamp [sec]

Alti

tude

[ft]

0

20

40

60

80

100

120

140

160

180

200

Spee

d [m

ph]

Altitude [ft]Speed [mph]

Airspeed and Rate of Climb


Instrumented R/C Aircraft Flight TestingStall and Flow Separation

Video Camera

Tufts


R/C Glider Design ProjectDescription: Students are given a foam wing, battery pack, and flexible servo package which they utilize to design and evaluate the performance of a hand-launched glider.

• Initial Measurements and Calculations– Wing, Battery, and Servo Package

Battery Package

Servo PackageWing


R/C Glider Design Project

• Conceptual Designs and Evaluation– Tail and boom configuration

Dual Tail Boom

Single Tail Boom

Tail Configuration



• Design Calculations– Tail length– Tail and control surface sizing (TVR)– Moment, force, and stability calculations

– Component dimensions and lay-out• Construction

FwFh.tail Fv.tail Ftb FbpFsp

AerodynamicCenter of the Wing

Ffb



• Performance

• Powered Flight

• Report


AE 460: Aerodynamics & Propulsion Lab

Description: Senior level course with in-class lectures and group laboratory exercises.

Topics cover basic concepts in aerodynamics and propulsion highlighting:

• Experimental methodologies• Diagnostics• Data analysis and presentation• Theoretical analysis• Reporting


AE 460: Laboratory Exercises

-1.0

0.0

1.0

2.0

3.0

4.0

5.0

6.0

0.000 0.002 0.004 0.006 0.008 0.010 0.012Time (Seconds)

Am

plitu

de (V

olts

)

Raw Waveform1 Harmonic2 Harmonics5 Harmonics10 Harmonics

Airfoil Pressure Distribution Experiment

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

-10 -5 0 5 10 15 20

Angle of Attack (degrees)

Lift

Coe

ffici

ent

LabView and Digital Data Collection,Control, and Analysis

Wind Tunnel Calibration, UncertaintyAnalysis and Pressure Measurement

Airfoil Lift and Surface Pressure Cylinder wake, drag, turbulence andhotwire anemometry

0

0.05

0.1

0.15

0.2

0.25

0.3

-5 -4 -3 -2 -1 0 1 2 3 4 5(Y-Y0)/D

σ/U

inf

X = 38 mm Hot-wireX = 89 mm Hot-wireX = 146 mm Hot-wire


AE 460: Jet Thrust and Schlieren Photography Objective: Students operate a subsonic and under-expanded supersonic jet over a range of conditions. Utilizing various methods and assumptions the thrust is calculated. Schlieren photography is used to characterize the flow field and shock/expansion waves.

• Experimental ArrangementSchlierenMirror

SchlierenLED

Balance

LoadCell

SchlierenOptics

Pressure/Controller

PressureRegulator

LoadCell

Jet

PitotProbe

StepperMotor

Acoustic Silencer


AE 460: Jet Thrust and Schlieren Photography

• Data Collection



• Data Analysis– Force & Moment Balance



• Data Analysis– Control Volume Analysis

[ ] ∫∫ +−=RR

atm drrrrvdrrPrPThrust0

222

02 2)()(2)( πρπ[ ] exitexitexitexitatmexit AVAPPThrust ρ2+−=

1. Bernoulli - constantdensity

2. Isentropic

3. Subsonic – Isentropicchoked flow



• Data Analysis– Velocity Profiles

Jet Velocity Profile

0

100

200

300

400

500

600

-20 -15 -10 -5 0 5 10 15 20Radius [mm]

Velo

city

[m/s

]

Me = 0.36: Bern.Me = 0.36: Isen.Me = 0.59: Bern.Me = 0.59: Isen.Me = 0.77: Bern.Me = 0.77: Isen.Me = 1.0: Bern.Me = 1.0: Isen.Me = 1.2: Bern.Me = 1.2: Isen.Me = 1.4: Bern.Me = 1.4: Isen.



• Data Analysis– Thrust Calculations

Jet Thrust

0

5

10

15

20

25

30

35

40

100 150 200 250 300 350

Stagnation Pressure [kPa]

Thru

st [N

]

Load CellBernoulli (Jet Exit)Isentropic (Jet Exit)Pitot Probe



• Data Analysis– Schlieren Flow Visualizations

Subsonic Normal shockUnder-expanded



• On-Line Laboratory


AE 460: Golf Ball Design LabObjective: Using a 6” x 6” subsonic tunnel students design a “better golf ball” and measure the drag, velocity and turbulence profiles, and frequency spectra in the wake. Students design the experimental plan and compare measurements with a standard golf ball and smooth sphere.

• Experimental Arrangement


AE 460: Golf Ball Design LabObjective: Using a 6in x 6in subsonic tunnel students design a “better golf ball” and measure the drag, velocity and turbulence profiles, and frequency spectra in the wake. Students design the experimental plan and compare measurements with a standard golf ball and smooth sphere.


Pitot/Static Probe

Hot FilmAnemometer

Traverse


AE 460: Golf Ball Design Lab


Calibration Program

Data Collection Program


AE 460: Golf Ball Design Lab

• Design lower drag sphere– Modify sphere to have lower grad without

changing volume by more than 10%


AE 460: Golf Ball Design Lab Data Collection

Direct Force Measurement

FD = (FLC – Fs) (LLC)/LS

FLC = Force of load cell (Lbf)Fs = Load cell reading with

sting only (Lbf)0

0.1

0.2

0.3

0.4

0.5

0.6

0 20000 40000 60000 80000 100000 120000Reynolds Number

CD

Smooth SphereGolf BallModified Sphere

Schlichting, Ref. 1

LLC Ls


Mean Velocity Measurements Turbulence Profiles

Momentum Deficit Smooth Sphere Frequency Spectra

AE 460: Golf Ball Design Lab Data Analysis

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

-1.5 -1 -0.5 0 0.5 1 1.5

(Y-Yo)/D

σu(

y)/U∞

SmoothGolf BallModifiedSmooth AvgGolf Ball AvgModified Avg

0.7

0.75

0.8

0.85

0.9

0.95

1

1.05

1.1

-1.5 -1 -0.5 0 0.5 1 1.5

(Y-Yo)/D

u(y)

/U∞

SmoothGolf BallModifiedSmooth AvgGolf Ball AvgModified Avg

7.60.430.4678500

7.10.390.4228200

% Difference

CD(Mom.Deficit)

CD(Load Cell)

Reynolds No.

0

0.5

1

1.5

2

2.5

3

0 100 200 300 400 500F r e q u e n c y [ H z ]

Sphere

Golf Ball

Modif iedSphere


AE 460: Diagnostics Demonstration Laboratories

Delta Wing

Laser Sheet Lighting Flow Visualization

Oil Surface Flow Visualization



Pressure Sensitive Paint (ISSI)

Innovative Scientific Solutions Inc.

LEDLamp

4-Jet

FilterWheel

Disk withPSP

12-BitCCD Camera



Pressure Sensitive Paint (ISSI)1.10

0.95

1.0

1.05



Particle Image Velocimetry and Micro-flows

Red and Green (delayed)Illumination Beam

SeededFlow

Color digitalCamera




Initial Image Delayed Image




Color DigitalCamera

Microscope

Delay PulseGenerator

Syringe Pump

Micro-Channel

Two Color LED







X/H

Y/H

-2 -1 0 1-1

-0.5

0

0.5

1

1101009080706050403020100

-10-20-30-40

U [mm/s]U [mm/s]




X/H

Y/H

-2 -1 0 1-1

-0.5

0

0.5

1

1101009080706050403020100

-10-20-30-40

U [mm/s]U [mm/s]


Conclusions and Lessons Learned

• Laboratories at the freshman (discovery) and senior level were described

• Multiple set-ups• Corporate memory of laboratory development• Development of routines to regularly check

calibrations and operation of instrumentation• Demonstrate good and poor (planned) data as part

of the lab• Carefully consider how much information to give for

data analysis

Documents

Undergraduate Laboratories in Aerospace Engineering · PDF file– AE 460: Aerodynamics & Propulsion Lab. ... 1-5 0 5 10 15 20 ... Airfoil Lift and Surface Pressure Cylinder wake,