9. Thermographic phosphors

• Introduction/Background/Theoryg y• Thermometry methods

– Temporal approach– Spectral approach– Calibration– 2D measurements2D measurements

• Applications– Fires– Decomposing material– IC engines– Aero enginesAero engines– Droplets/Sprays

• New trends & applications

M. Aldén, A.Omrane, M. Richter and G. Särner, “Thermographic phosphors for thermometry: A survey of combustion applications”, Progress in Energy and Combustion Science 37, 422-461 (2011)

Thermographic phosphors for temperature measurementstemperature measurements

• Industrial and scientific applications.

• Powder(1-10µm), ( µ ),sensitivity from cryogenic to 2000K.y g

• Excitation: UV (light), laser e-beamlaser, e beam.

Physical descriptiony p

• Host inorganic material (ceramic) doped with and an activator (rare earth metal)~1 %.and an activator (rare earth metal) 1 %.

• Host material transparent, laser energy b b d b th ti tabsorbed by the activator.

• Through complex interactions in the g pelectronic configuration of the activator and the host temperature will influence thethe host, temperature will influence the spectral and temporal behaviour of the emissionemission

Thermometry MethodsThermometry Methods

Lif ti th d D ti• Lifetime method: Decay time.

• Spectral method: Ratio between• Spectral method: Ratio betweenemission lines.

• Emission line shift and linebroadning.

Ab i• Absorption

• Excitation• Excitation

Lifetime method: Decay timeLifetime method: Decay time

Spectral method: Ratio between emission linesemission lines.

Temperature dependent phosphorsSummary of some phosphorsSummary of some phosphors

Särner et al. Meas. Sci Techn. 2008,

Calibration proceduresCalibration procedures

Calibration proceduresCalibration procedures

YAG: Dy

Calibration procedures

2D measurements: Spectral methodp

2D measurements: Temporal method2D measurements: Temporal method

Application 1: Fire studies

Experimental setup

•Excitation 266 or 355 nm

•Fuel: Alcohol and Heptane.p

•Detection: Framing Camera.

•Material: LDF and PMMA•Material: LDF and PMMA.

Results

Application 2. Decomposing materialmaterial

Surface temperature of a woodparticle during pyrolysiswoodparticle during pyrolysis

723

)

673

atur

e(K

)

623empe

ratu

623

Tem

0 100 200573

Time(seconds)

Application 3: IC engines

Results

Intake valves

Exhaust valves

Surface measurements in a “production” diesel engine using thermographic phosphors and optical fibers

Application 4: Aircraft engineApplication 4: Aircraft engine

Experimental arrangement

Segment of flameholder t d ith h h t i l

Nd:Yag laser=266 nm

coated with phosphor material

Lens + Filter 657 nm + PMT + Transimpedance amplifier

ResultsResultsTemperature data (lifetime decays) was recorded at the repetition rate of the

it ti l (10 H )excitation laser (10 Hz).

Signals were sampled using a 1 GHz bandwidth oscilloscope (LaCroy).

Power Level (PL) versus time for test cycle B

Temperature data measured for test cycle Bcycle B. cycle B.

2D experiments

Investigated SurfaceInvestigated Surface

•Use of YAG:Dy

•Excitation at 355 nm

•Emission at 458 and 493 nm

Experimental

Single ShotAveraged Temperature Image

Application 5: Droplet/spray

One point measurementsOne-point measurements

Droplets in acoustic levitationDroplets in acoustic levitation

Results: Droplets and Sprays

Results: Realistic spray

Some further development and application• Simultaneous velocity & temperature measurements

A. Omrane, P. Petersson, M. Aldén and M. A. Linne ”, Simultaneous 2D flow velocity and gas temperature

measurements using thermographic phosphors Appl Phys B Appl Phys B92 99-102 (2008)measurements using thermographic phosphors, Appl. Phys. B. Appl. Phys B92, 99-102 (2008).

• UV and blue emitting phosphors & short decay time;

G Särner, M Richter, M Aldén, “Two-dimensional thermometry using temperature induced line shifts of ZnO:Zn and

ZnO:Ga fluorescence” Opt Lett 33 1327(2008)ZnO:Ga fluorescence”, Opt Lett. 33, 1327(2008)

• Thermometry using multiple scattering

G. Särner, U. Göransson, M. Richter and M. Aldén, Surface temperatures measured through a heated solid porous

material using diffusive scattered laser induced phosphorescence, Submitted to Fire and Materials 2011

More:

Extended temperature range (custom made phosphors);

C. Eckert, C. Pflitsch, B. Atakan, ”Sol-gel deposition of multiply doped thermographic

phosphor coatings (Al2O3:Cr3+, M3+) (M=Dy, Tm) for wide range surface

temperature measurement application”, Prog. in Organic Coatings. 67, 116 (2010)

Flame survivability; Yu et al. Meas. Sci. Techn (2010)

Pressure and gas composition effects; Brubach et al Meas Sci Techn (2007)Pressure and gas composition effects; Brubach et al, Meas. Sci. Techn. (2007)

Laser-induced effects, e.g. heating; Lindén et al. Appl. Phys. B (2009)

Influences from phosphor thickness; Knappe et al. SAE Congress 20100

Simultaneous temperature/velocity: LIP + PIVtemperature/velocity: LIP + PIV

Laminar flow: Average of 50 imagesimages

Turbulent flow: Average of 50 imagesimages

Some further development and application• Simultaneous velocity & temperature measurements

A. Omrane, P. Petersson, M. Aldén and M. A. Linne ”, Simultaneous 2D flow velocity and gas temperature

measurements using thermographic phosphors Appl Phys B Appl Phys B92 99-102 (2008)measurements using thermographic phosphors, Appl. Phys. B. Appl. Phys B92, 99-102 (2008).

• UV and blue emitting phosphors & short decay time;

G Särner, M Richter, M Aldén, “Two-dimensional thermometry using temperature induced line shifts of ZnO:Zn and

ZnO:Ga fluorescence” Opt Lett 33 1327(2008)ZnO:Ga fluorescence”, Opt Lett. 33, 1327(2008)

• Thermometry using multiple scattering

G. Särner, U. Göransson, M. Richter and M. Aldén, Surface temperatures measured through a heated solid porous

material using diffusive scattered laser induced phosphorescence, Submitted to Fire and Materials 2011

More:

Extended temperature range (custom made phosphors);

C. Eckert, C. Pflitsch, B. Atakan, ”Sol-gel deposition of multiply doped thermographic

phosphor coatings (Al2O3:Cr3+, M3+) (M=Dy, Tm) for wide range surface

temperature measurement application”, Prog. in Organic Coatings. 67, 116 (2010)

Flame survivability; Yu et al. Meas. Sci. Techn (2010)

Pressure and gas composition effects; Brubach et al Meas Sci Techn (2007)Pressure and gas composition effects; Brubach et al, Meas. Sci. Techn. (2007)

Laser-induced effects, e.g. heating; Lindén et al. Appl. Phys. B (2009)

Influences from phosphor thickness; Knappe et al. SAE Congress 20100

New phosphors: Blue, fast and p pvery temperature sensitive!

Ratio calibration for ZnO:Ga and ZnO:Zn

Särner et al. Opt Lett 2008

2D temperature measurements in a burning droplet using ZnO:Ga

Särner et al. Opt Lett 2008

Some further development and application• Simultaneous velocity & temperature measurements

A. Omrane, P. Petersson, M. Aldén and M. A. Linne ”, Simultaneous 2D flow velocity and gas temperature

measurements using thermographic phosphors Appl Phys B Appl Phys B92 99-102 (2008)measurements using thermographic phosphors, Appl. Phys. B. Appl. Phys B92, 99-102 (2008).

• UV and blue emitting phosphors & short decay time;

G Särner, M Richter, M Aldén, “Two-dimensional thermometry using temperature induced line shifts of ZnO:Zn and

ZnO:Ga fluorescence” Opt Lett 33 1327(2008)ZnO:Ga fluorescence”, Opt Lett. 33, 1327(2008)

• Thermometry using multiple scattering

G. Särner, U. Göransson, M. Richter and M. Aldén, Surface temperatures measured through a heated solid porous

material using diffusive scattered laser induced phosphorescence, Submitted to Fire and Materials 2011

More:

Extended temperature range (custom made phosphors);

C. Eckert, C. Pflitsch, B. Atakan, ”Sol-gel deposition of multiply doped thermographic

phosphor coatings (Al2O3:Cr3+, M3+) (M=Dy, Tm) for wide range surface

temperature measurement application”, Prog. in Organic Coatings. 67, 116 (2010)

Flame survivability; Yu et al. Meas. Sci. Techn (2010)

Pressure and gas composition effects; Brubach et al Meas Sci Techn (2007)Pressure and gas composition effects; Brubach et al, Meas. Sci. Techn. (2007)

Laser-induced effects, e.g. heating; Lindén et al. Appl. Phys. B (2009)

Influences from phosphor thickness; Knappe et al. SAE Congress 20100

Phosphorescence thermometry th h lti l tt ithrough multiple scattering

Laser, 266 nm 360LIP using CdWO

4 inside styrofoam

Above

Calorimeter340

350

/ K

AboveBelow (through the styrofoam)

PMT Phosphorpowder 320

330

Tem

pera

ture

/ K

Polystyrene

300

310

PMT

0 1 2 3 4 5 6 7290

Time / min

Some further development and application• Simultaneous velocity & temperature measurements

A. Omrane, P. Petersson, M. Aldén and M. A. Linne ”, Simultaneous 2D flow velocity and gas temperature

measurements using thermographic phosphors Appl Phys B Appl Phys B92 99-102 (2008)measurements using thermographic phosphors, Appl. Phys. B. Appl. Phys B92, 99-102 (2008).

• UV and blue emitting phosphors & short decay time;

G Särner, M Richter, M Aldén, “Two-dimensional thermometry using temperature induced line shifts of ZnO:Zn and

ZnO:Ga fluorescence” Opt Lett 33 1327(2008)ZnO:Ga fluorescence”, Opt Lett. 33, 1327(2008)

• Thermometry using multiple scattering

G. Särner, U. Göransson, M. Richter and M. Aldén, Surface temperatures measured through a heated solid porous

material using diffusive scattered laser induced phosphorescence, Submitted to Fire and Materials 2011

More:

Extended temperature range (custom made phosphors);

C. Eckert, C. Pflitsch, B. Atakan, ”Sol-gel deposition of multiply doped thermographic

phosphor coatings (Al2O3:Cr3+, M3+) (M=Dy, Tm) for wide range surface

temperature measurement application”, Prog. in Organic Coatings. 67, 116 (2010)

Flame survivability; Yu et al. Meas. Sci. Techn (2010)

Pressure and gas composition effects; Brubach et al Meas Sci Techn (2007)Pressure and gas composition effects; Brubach et al, Meas. Sci. Techn. (2007)

Laser-induced effects, e.g. heating; Lindén et al. Appl. Phys. B (2009)

Influences from phosphor thickness; Knappe et al. SAE Congress 20100

Experimental SetupExperimental Setup – 2 Temperatures from 1 Phosphor Layer

λ/2 plate + pol. beam splitter

Phosphor

Optical Engine

• 10Hz laser rep. rate @ 1200rpm=> 1 shot (= 2 LIP temperatures) / combustion cycle

• 2 Phosphor Thicknesses tested @ 32µm and 59µm

Comparison between two different Phosphor thicknesses

Further needs

• Nano phosphorsp p

• Phosphors for high temperaturep g p