1. 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 Telephone (765) Fax       (765)

2. Objective
Measure temperature distribution and heat transfer distribution on a hydraulic experiment at Beihang University in the next three weeks.

3. Temperature Sensitive Paint
Emission
Luminescent
Molecule
Excitation
Quantitative
Heat Flux
Lamp LED
CCD camera
Feature Detection
-Transition
-Vortices
-Separation
Mach 10 –Tunnel 9
High-mass planetary probes are affected by transition
Laminar flow results in 2-8 times less aeroheating

4. 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
TSP -Temperature Sensitive Paint
PSP - Pressure Sensitive Paint

5. Temperature Sensitive Paint
High temperature causes non-radiative decay
“thermal quenching”
Obeys Arrhenius relation:
For limited temp. range
Similar molecules to
PSP, but in oxygen
impermeable binder

6. Luminescent Paint (TSP/PSP)
Data Processing
Iref/I
P/Pref
calibration
Acquisition
photodetector
long-pass filter
Iref/I
P/Pref
Excitation
short-pass filter
excitation source
surface map
low cost
easy to apply
coated model

7. 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)

8. Basic Photophysics

9. Jablonski Diagram

10. Data Reduction Methods

11. Data Reduction Methods
Intensity Reference
Multi-luminophore Paint
Time Based Methods

12. Intensity Reference Wind Off / Wind On
Corrects for non-uniform model motion, nonuniform concentration

13. Multi-luminophore Paint
Luminescent molecules with different pressure and temperature sensitivities, overlapping excitations and different emission wavelengths

14. Time Based Methods
Direct Decay
Phase Based

15. Direct Decay Modulated Light Source Point Systems
Pulse, Sine wave, square wave
Point Systems
Camera Systems with image intensifier
Time
Intensity

16. Phase Based Lock-in Amplifier
FLIM (Fluorescent Lifetime Imaging Method)
tan()= 

17. Temperature Sensitive Paint TSP
Same or similar Luminophore as in PSP
Oxygen impermeable binder

18. Global Surface Temperature Measurements
Toolbox
Temperature Sensitive Paint
Thermographic Phosphors
Infrared Camera
Temperature Sensitive Liquid Crystals
Array of Thermocouples

19. Temperature Sensitive Paint
Surface Temperature
Correction for Pressure Sensitive Paint
Transition Detection
Quantitative Heat Transfer
Shear Stress - Heat transfer Analogy

20. Temperature Sensitive Paint Calibrations

21. TSP Time Response Laser Pulse Heating c specific heat paint thickness
 density of polymer
c specific heat
paint thickness
h convection heat transfer coefficient

22. Ruthenium based TSP tris(2,2’-bipyridyl)ruthenium - Ru(bpy)
Excitation and Emission Spectrum of a Ruthenium Based Paint

23. EuTTA based TSP Europium III Thenoyltrifluoroacetonate EuTTA
Emission Spectrum
Excitation Spectrum

24. EuTTA in Model Airplane Dope

25. Applications Temperature Sensitive Paint (TSP)
Transition Detection
Low Speed
Cryogenic Wind Tunnel
Quantitative Heat Transfer
Camera Based – M=10
Scanning System Laser Spot Heating

26. Transition Detection Low Speed
TSP –EuTTA in dope
Wing heated with
photographic spot lamps
to ~20 C above ambient
8 bit Camera

27. Results
Low Speed Transition
Raw Image
(false color)

28. Quantitative Heat Transfer

29. Heat Transfer Data Reduction
Method 1
Model make out of Thermally Insulating material
Measure
Match the temperature to analytic solution for a semi-infinite body (Cook-Felderman)
Make Model out of a Conductor with a thin insulator on the surface
Method 2

30. Tunnel #9
M=10
Run time ~1.0 sec
1.5 meter Diameter

31. TSP - EuTTA in dope
Metal model
Insulating Layer – mylar film (model airplane monokote)
50 microns thick
Raw Image

34. Mach-6 Quiet Tunnel

35. HIFiRE-5 Model
Quiet Flow, α=0
Re = 2.6*106 /ft

36. TSP Measurements of
Material Temperature
Temperature profiles from TSP measurement of grinding stainless
steel at spark-out condition
Temperature profile of machining
acquired with TSP sensor (Rubpy)