Transcript Purdue University - School of Aeronautics and Astronautics

Molecular Sensors
Temperature Sensitive
Paint
John Sullivan
Professor – School of Aeronautics and Astronautics
Director - Center for Advanced Manufacturing
Purdue University
Special Government Employee – NASA
West Lafayette, IN 47907-2022
Telephone (765)494-1279
Fax
(765)496-1180
[email protected]
Purdue University - School of Aeronautics and Astronautics
Objective
• Measure temperature distribution and
heat transfer distribution on a hydraulic
experiment at Beihang University in the
next three weeks.
Purdue University - School of Aeronautics and Astronautics
Temperature Sensitive Paint
Emission
Excitation
Quantitative
Heat Flux
Feature Detection
-Transition
-Vortices
-Separation
Mach 10 –Tunnel 9
High-mass
planetary
probes
are and
affected
by transition
Purdue
University - School
of Aeronautics
Astronautics
Laminar flow results in 2-8 times less aeroheating
Detector
Excitation
UV Lamp
Laser
Flash Lamp
Optical
Filter
Emission
CCD
PMT
PD
Calibrate Output
for Temperature
or Pressure
Luminescent Molecule
Binder
Polymer
Porous Solid
TSP -Temperature Sensitive Paint
PSP - Pressure Sensitive Paint
Photo-physical process:
-absorb a photon
-transition to excited state
-Oxygen quenching (PSP)
or thermal quenching (TSP)
=> Pressure and/or temperature
dependent luminescent intensity
and luminescent lifetime
Purdue University - School of Aeronautics and Astronautics
Temperature Sensitive Paint
High temperature causes non-radiative decay
“thermal quenching”
• Obeys Arrhenius relation:
For limited temp. range
 I(T) 
E


ln
  R
 I ref (Tref ) 
g
 1
1


Tref
 T



• Similar molecules to
PSP, but in oxygen
impermeable binder
I 1 to 5%
~ 0
T
C
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Luminescent Paint (TSP/PSP)
Acquisition
Data Processing
P/Pref
Iref/I
calibration
Iref/I
P/Pref
Excitation
excitation source
photodetector
long-pass filter
short-pass filter
surface map
low cost
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coated model
easy to apply
Current State of the Art of
PSP/TSP
•Temperature Sensitive Paint
–T= -196 C to 200 C M=.01 to 10
–Accuracy 1 Degree Centigrade Resolution <. 01 C
–Time Response 1 sec Typical (<1 ms demonstrated)
•Pressure Sensitive Paint
–P=.001 to 2 atm M=.05 to 5
–Accuracy 1.0 mbar Resolution .5 mbar
–Time response .5 sec Typical
( 1 microsec demonstrated)
Purdue University - School of Aeronautics and Astronautics
Basic Photophysics
Purdue University - School of Aeronautics and Astronautics
Jablonski Diagram
Sn
kic
S2
vibration
kisc
kic
S1
intersystem crossing (ISC)
T1
(singlet state)
h
excitation
(triplet state)
kic
f
kisc
fluorescence
p
phosphorescence
S0
(ground state)
internal conversion (IC)
Purdue University - School of Aeronautics and Astronautics
Data Reduction Methods
Purdue University - School of Aeronautics and Astronautics
Data Reduction Methods
• Intensity Reference
• Multi-luminophore Paint
• Time Based Methods
Purdue University - School of Aeronautics and Astronautics
Intensity Reference
 ref
p

 A(T )  B(T )
I

pref
I ref
• Wind Off / Wind On
• Corrects for non-uniform model
motion, nonuniform concentration
Purdue University - School of Aeronautics and Astronautics
Multi-luminophore Paint
• Luminescent molecules with different
pressure and temperature sensitivities,
overlapping excitations and different
emission wavelengths
Purdue University - School of Aeronautics and Astronautics
Time Based Methods
• Direct Decay
• Phase Based
Purdue University - School of Aeronautics and Astronautics
Direct Decay
• Modulated Light Source
– Pulse, Sine wave, square wave
• Point Systems
• Camera Systems with image intensifier
Intensity
Time
Purdue University - School of Aeronautics and Astronautics
Phase Based
• Lock-in Amplifier
• FLIM (Fluorescent Lifetime Imaging Method)
 ref
P
 C(t)  D(t)

P







ref
tan()=

3
amplitude(arb)







2
1
Excitation
Emission
0
0
5
10
15
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t(arb)
Temperature Sensitive Paint
TSP
Same or similar Luminophore as in
PSP
Oxygen impermeable binder
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Global Surface Temperature
Measurements
Toolbox
Temperature Sensitive Paint
Thermographic Phosphors
Infrared Camera
Temperature Sensitive Liquid Crystals
Array of Thermocouples
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Temperature Sensitive Paint
• Surface Temperature
– Correction for Pressure Sensitive Paint
• Transition Detection
• Quantitative Heat Transfer
• Shear Stress - Heat transfer Analogy
Purdue University - School of Aeronautics and Astronautics
Temperature Sensitive Paint Calibrations
Purdue University - School of Aeronautics and Astronautics
TSP Time Response
Laser Pulse Heating

 
 c
h
 density of polymer
c specific heat
 paint thickness
h convection heat transfer coefficient
Purdue University - School of Aeronautics and Astronautics
Ruthenium based TSP
tris(2,2’-bipyridyl)ruthenium - Ru(bpy)
400
Intensity (arb units)
300
Excitation
Emission
200
100
0
200
UV
lamp
300
Blue Green
LEDs laser
400
500
600
700
800
Wavelength (nm)
900
Excitation and Emission Spectrum of a
Ruthenium Based Paint
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EuTTA based TSP
Europium III Thenoyltrifluoroacetonate
EuTTA
Excitation Spectrum
Emission Spectrum
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EuTTA in Model Airplane Dope
Purdue University - School of Aeronautics and Astronautics
Applications
Temperature Sensitive Paint
(TSP)
•
Transition Detection
– Low Speed
– Cryogenic Wind Tunnel
•
Quantitative Heat Transfer
– Camera Based – M=10
– Scanning System Laser Spot Heating
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Transition Detection
Low Speed
TSP –EuTTA in dope
Wing heated with
photographic spot lamps
to ~20 C above ambient
8 bit Camera
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Results
Low Speed Transition
Raw Image
(false color)
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Quantitative Heat Transfer
Purdue University - School of Aeronautics and Astronautics
Heat Transfer Data Reduction
Method 1
• Model make out of Thermally Insulating material
• Measure
Tsurface(t )
kmodel  1
• Match the temperature to analytic solution for a
semi-infinite body (Cook-Felderman)
Method 2
• Make Model out of a Conductor with a thin
insulator on the surface
q  k / (Tsurface  Tmodel )
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k model  1
Tunnel #9
M=10
Run time ~1.0 sec
1.5 meter Diameter
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TSP - EuTTA in dope
Metal model
Insulating Layer – mylar film (model airplane monokote)
50 microns thick
Raw Image
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Purdue University - School of Aeronautics and Astronautics
Purdue University - School of Aeronautics and Astronautics
Mach-6 Quiet Tunnel
Purdue University - School of Aeronautics and Astronautics
National Aeronautics and Space Administration
HIFiRE-5 Model
Quiet Flow, α=0
run8.tif
4
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
-0.2
-0.2
-0.4
-0.4
-0.6
-0.6
-0.8
-0.8
-1
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
4
[W/m 2]
x 10
1
HFS-4
[W/m 2]
paints
Q
x 10
Re = 2.6*106 /ft
Q
4
1
-1
4.5
www.nasa.gov
35
TSP Measurements of
Material Temperature
80
250
Cutting
tool
Chip
70
300
60
350
50
40
400
Area
of
Interest
Temperature profiles from
TSP measurement of
grinding stainless
Temperature profile of machining steel at spark-out
acquired with TSP sensor (Rubpy)
condition
450
workpiece
350
400
450
500
550
30
600
20
degree C
Purdue University - School of Aeronautics and Astronautics