AIAA General Meeting

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AIAA General Meeting

• 2006 Aerospace Undergraduate Summer Research
• Wednesday October 25, 2006

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Danny Lau

• First Presentation by

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Structural Health Monitoring

• Danny, Lau

Professor Carlos E.S. Cesnik Mr. Ajay Raghavan
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Introduction

• Structural health monitoring (SHM) is an area of
  active research in engineering.
• Guided Wave (GW) testing with hand-held
  transducers is most commonly used for offline
  inspection.

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• There has been an emerging need for damage
  prognosis system in aerospace industry after
  several accidents.
• For most aerospace structures, permanent
  integration of SHM system is required to provide
  instant health monitoring.

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Summer Research Overview

• MFC Experiment
• FEM Simulation
• Modeling Wave Propagation in Composite
• Autoclave Experiment Setup

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MFC Experiment

• Conformal anisotropic macro fiber composite (MFC)
  transducers were tested on aluminum plate.

Figure 1 MFC experiment with amplifier
Figure 2 MFC on aluminum plate
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• The actuation voltage and the peak to peak sensor
  response were collected .
• The normalized sensor response for A0 and S0 mode
  was plotted versus center frequency.

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Figure 3 Graph of sensor response versus center
frequency, A0 mode
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FEM Simulation

• Earlier GW modeling work done assumed uncoupled
  dynamics between the transducer and underlying
  substrate.
• When the transducer thickness and stiffness were
  comparable to the substrates, some deviation has
  been found between the two results.

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• Analytical models incorporating the coupled
  transducer-substrate dynamics can be complex.
• Finite element method (FEM) simulations were run
  in Abaqus v.6.5 to examine whether incorporating
  transducer mass and stiffness might improve
  correlation with experiment.

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Figure 4 Basic setting for FEM
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Figure 5 displacement of the sensor (S mode)
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Modeling Wave Propagation in Composite

• AS4/3501-6 Carbon-Carbon Composite

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• The Phase velocity and group velocity curves were
  generated in Disperse 2.0
• The data was inputted in a Matlab code to plot
  the Normal surface and Slowness surface at
  different frequency.

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Figure 6 Normal surface (150 kHz, A0)
Figure 7 Normal surface (150 kHz, S0)
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Autoclave Experiment Setup

• To examine the effect of temperature on the GW
  propagation in plates.
• To test different epoxies and examine their
  effects on transducer coupling.
• An aluminum plate was used as testing media and
  three different kinds of epoxies were used to
  bond the actuators and sensors.

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Figure 8 Final setup of the experiment
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Conclusion

• Practice computational skills.
• Learn to use laboratory equipments.
• Gain some experiences in doing research project.
• I would like to thank the Aerospace department
  for the funding and Professor Cesnik and Mr.
  Raghavan for giving me valuable advise.

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Shareil Elia

• Next Presentation by

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Diode Laser-Based Flight Test Instrumentation
for Scramjets

• Propulsion Turbulent Combustion Laboratory

Sponsoring Faculty Professor James F. Driscoll
Research Assistants Jeff Pederson Shareil Elia
Partners Air Force Office of Scientific
Research Southwest Sciences
University of Michigan Department of Aerospace
Engineering
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Outline

• Motivation
• Technological Background
• Description of Work
• Current overall Project Status
• Questions

University of Michigan Department of Aerospace
Engineering
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Motivations

• Combustion Control
• Inexpensive measurement of key species in
  combustion exhaust
• Diagnosis closed-loop control of combustion
  process
• Non-Intrusive Sensors
• Near-real-time measurement of the temperature of
  reacting flows
• Temperature Profile across combustor

University of Michigan Department of Aerospace
Engineering
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Advantages of Diode Laser Sensor System

• Relatively cheap
• Widely Available
• Fast response time
• Good sensitivity
• Rugged Tunable

University of Michigan Department of Aerospace
Engineering
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Molecular Atomic Spectroscopy

• Absorption spectrum is a characteristic of a
  particular compound
• Laser could be tuned to detect a given species
  concentration
• The engine operating condition could be
  determined based on species concentration (i.e.
  CH4, O2, CO2, CO and H2O)

University of Michigan Department of Aerospace
Engineering
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Beers Law of Absorption (Premixed Flat-Flame
Assumptions)
University of Michigan Department of Aerospace
Engineering
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Description of Work

• Calibrating the Sensor System
• Set up a variable-pressure premixed burner
• Simulate premixed burner
• Measure temperature using NO LIF (Laser Induced
  Fluorescence)
• Measure Species Concentration and Temperature
• Conducting Tests at Michigan Combustion
  Wind-Tunnel
• Integrate the sensor system to combustion wind
  tunnel
• Measure non-reacting cavity flows

University of Michigan Department of Aerospace
Engineering
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Hydrocarbon Fuel Combustion
University of Michigan Department of Aerospace
Engineering
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Computational Analysis
University of Michigan Department of Aerospace
Engineering
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Fuel-Board Operation
University of Michigan Department of Aerospace
Engineering
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CEA Simulations

• Will be used as a benchmark to verify the
  accuracy of the detector system

University of Michigan Department of Aerospace
Engineering
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Experimental Setup
University of Michigan Department of Aerospace
Engineering
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(No Transcript)
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Project Progress Status

• Calibrating the Sensor System
• Set up a variable-pressure premixed burner
• Simulate premixed burner
• Measure temperature using NO LIF (Laser Induced
  Fluorescence)
• Measure Species Concentration and Temperature
• Conducting Tests at Michigan Combustion
  Wind-Tunnel
• Integrate the sensor system to combustion wind
  tunnel
• Measure non-reacting cavity flows

University of Michigan Department of Aerospace
Engineering
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Questions?
University of Michigan Department of Aerospace
Engineering
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Xing Tai, Loy

• Next Presentation by

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Stalker 2006 Presentation
Finite element Modeling of Truss Core Panels

• Xing Tai, Loy

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Research is For Dummies

• An introduction into the sometime daunting world
  of research

• General Approach
• Specific Problems Faced

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Normal Homework Problem
Analysis Synthesis
Problem
Solution
Right
GSI or Professor
Wrong (Feedback Loop)
Textbooks Course Notes
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Research Problem
?
Analysis Synthesis
Problem
Solution
Right ?
Wrong ?
?
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Iterative Process
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Solution
Right ?

• Solve a simpler problem (one you already know
  the answer to)
• Change one variable keeping others constant
• Gain Insight into how the system behaves
• Documentation, Documentation Documentation!

Wrong ?
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Problem
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Problem
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Iterative Process
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Iterative Process
Limit Load of Non-Linear Beam Model
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Experimental Analysis
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Yeon Sik, Baik

• Next Presentation by

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Summer Undergraduate Research Presentation
Particle Image Velocimetry (PIV) Experiment to
Capture Laminar Separation Bubble (LSB) Yeon
Sik, Baik
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Overview

• Airfoil selection and manufacturing
• PIV instrumentation setup
• PIV pictures
• Wake data
• Boundary layer profile

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Airfoil Selection and Manufacturing

• Airfoil SD7003
• Low Re (50,000 100,000)
• Long separation region (0.2c 0.4c)
• Sufficient boundary layer height

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Airfoil Selection and Manufacturing (cont.)

• Manufactured using the CNC router
• Material used Balsa wood
• Dimensions 5.7 in. x 22 in.

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PIV Instrumentation Setup
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PIV Instrumentation Setup (cont.)
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PIV Pictures
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PIV Pictures
Magnification 8 px/mm
a 2
a 10
Magnification 33 px/mm
0.95c
0.2c
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Wake Data

• Wake velocity profile obtained 1.5c and 1.85c
  downstream from the trailing edge
• Cd 2?/c
• Cd values were relatively close to the XFOIL Cd
  values

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Boundary Layer Profile

• Glare displacement too large
• Remove bad data points by calculating the maximum
  glare displacement
• Magnification used 33 px/mm

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Boundary Layer Profile (cont.)
5 m/s , a 4 , 33 px/mm
0.2c
0.4c
0.6c
0.95c
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Boundary Layer Profile (cont.)
10 m/s , a 4 , 33 px/mm
0.2c
0.4c
0.6c
0.95c
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Boundary Layer Profile (cont.)
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Conclusion

• Drag coefficient values calculated from PIV
  instrumentation agreed with XFOIL data
• Due to thick glare displacement, LSB could not be
  captured
• Boundary layer thickness comparison indicates
  that the geometry of manufactured airfoil is
  inaccurate (Leading edge Trailing edge)
• Early separation and reattachment points

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Erik Komendera

• Next Presentation by

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Magnetic Field MapperAutomated Data Acquisition
System
Erik Komendera 25 October 2006 Plasmadynamics And
Electric Propulsion Laboratory (PEPL)
NASA 173M V.1 Hall Thruster
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Reasoning

• Magnetic Field is important to know for
  researching Hall thruster performance
• Manual measurements are tedious and
  time-consuming
• Automated System can perform thousands of
  measurements in two hours
• Enables visualization of fine details and/or
  anomalies
• Better data, better research

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Hall Thrusters

• Radial B field
• Axial E field
• Hall Parameter W
• High W
• e- (rotational)
• Low W
• Xe (axial)
• THRUST

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Hall Thrusters

• Magnetic Field Provided By
• Inner Magnet Coil
• Outer Magnet Coil
• Trim Coil (enhances magnetic lens effect)

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Hall Thrusters

• Magnetic Lens helps increase efficiency

Linnell, J., Gallimore, A. Internal Plasma
Structure Measurements of a Hall Thruster Using
Plasma Lens Focusing
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Task

• Automatically create mesh of points based on a
  few inputs
• Move 3-Axis Probe along cylindrical axes to each
  point
• Measure B-field
• Save to a Tecplot data file

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Auxiliary Equipment

• LabVIEW VI
• Motion Controller
• Gaussmeter
• Computer
• NASA 173M V.1 Thruster
• Power Supplies

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One Sweep 2.5 hours 1512 data points - 7
planes - 6 x 36 per plane 4536
measurements Unprecedented Level of Visualization
Magnetic Field Magnitude B - Arbitrary View
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Data Acquisition

• NASA 173M V.1 Hall Thruster
• At 0, 15 90 degrees
• 6 radial positions, 36 depth positions
• Total 1512 data points
• Current settings ?

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Data vs. Theory
Magnetic Lens evident in Cases Without Trim Coil
(top), With Trim Coil (bottom)
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System Results

• Data to be analyzed and interpreted by the
  researchers at PEPL
• 52-page manual for System Operation
• Can be used with any Hall Thruster or magnetic
  device
• Can be adapted to measure other parameters such
  as electric field (E).
• Speeds up data acquisition so more time can be
  spent analyzing

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Acknowledgements

• Undergraduate Award Committee
• Dr. Alec Gallimore - PEPL
• Bryan Reid PEPL Researcher
• Provided the task
• Structural assistance
• Jesse Linnell PEPL Researcher
• Thruster operational assistance

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AIAA this concludes our meeting

• 2006 Aerospace Undergraduate Summer Research
• Wednesday October 25, 2006
• Thanks for attending!