TSI Incorporated Copyright© 2008 TSI Incorporated Phase Doppler Particle Analyzer 2007 TSI LDV/PDPA...

Copyright© 2008 TSI Incorporated

TSI Incorporated

Phase Doppler Phase Doppler Particle AnalyzerParticle Analyzer

2007 TSI LDV/PDPA Workshop & Training

Presented by Joseph Shakal Ph.D.


TSI Incorporated

Phase Doppler Particle Phase Doppler Particle AnalyzerAnalyzer

• Light scattering principles and the phase Doppler method

• Measuring the phase of the scattered fringe pattern

• Validation techniques and error sources

• FlowSizer Software

• Measurement examples


TSI Incorporated

Light Scattering Principles Light Scattering Principles and the Phase Doppler and the Phase Doppler

MethodMethod• System Layout

• Fringe Patterns

• Reflective and Refractive Scatter


TSI Incorporated

ReceivingOptics

Optics

Fringes Move

Photo-detectors Signal Processor

FSA

Laser

Fiber-optic

Schematic of Phase Doppler Schematic of Phase Doppler OpticsOptics

C

BA

ReceivingAngle

FireWirePDM

FlowSizer

Slit

Particle


TSI Incorporated

Actual Fringe PatternsActual Fringe Patterns

At Crossing Away from Crossing


TSI Incorporated

Incident Beam (partially shown

for clarity)

Rainbow Angleat ~140 deg

m

Reflection p = 0

p = 2Refraction

p = 1

Light Scattering by a Light Scattering by a DropletDroplet

Different ComponentsDifferent Components

Rays scattered at ~30 deg


TSI Incorporated

Measuring the Phase of the Measuring the Phase of the Scattered Fringe PatternScattered Fringe Pattern

• Generation of Fringes by Droplets

• Fringe Spacing of the Scattered Light Pattern

• Reflective and Refractive Fringes

• Obtaining the Phase with a Three-Detector Receiver

• Detector Spacing


TSI Incorporated

Phase Shift of Light Phase Shift of Light Refracted Through a SphereRefracted Through a Sphere

• Two representative rays are pulled out of the crossing beams• Light rays enter the drop at different angles• Passing on different optical paths to reach an arbitrary point “P” results in a

phase shift between the two rays• Phase shift results in constructive and destructive interference

in the surrounding space

m

Ray 2

Ray 1

P

Enlarged View


TSI Incorporated

Scattered Fringe PatternScattered Fringe Pattern(small particle in the measuring volume)(small particle in the measuring volume)

Fringe pattern in the measuring volume, as seen by the receiver

Scattered fringe pattern

(No shift)

SABS

f


TSI Incorporated

Scattered Fringe PatternScattered Fringe Pattern(large particle in the measuring volume)(large particle in the measuring volume)

Scattered fringe pattern

(No shift)

SABS

f

Fringe pattern in the measuring volume, as seen by the receiver


TSI Incorporated

Signal A

Signal B

Signal C

Refraction

Signal C

Optimized Three Detector Optimized Three Detector ApproachApproach

Signal A

Signal B

Reflection

C

BA

Refr

act

ion

Reflect

ion

View into Front of Receiver

Intensity Pattern

Phase AB

Phase AC

Phase AB

Phase AC

Droplet is currently in the Beam Waist


TSI Incorporated

Phas

e

Original Detector

Arrangement

Diameter

Optimized Three-Detector Optimized Three-Detector ApproachApproach

C

AB

AB)

AC)0

180

360

AC AB

C

ABOptimized

Detector Arrangemen

t

d1


TSI Incorporated

Optimized PDPA ReceiverOptimized PDPA Receiver

• No masks needed

• No planar phases measured

• Detector Areas same as Detection Areas

• Collimated light input to fibers

• Ideal fiber packing ratio

• Non-integer detector spacing ratio → leads to non-integer phase ratio

C

A

B


TSI Incorporated

Non-Integer Phase RatioNon-Integer Phase Ratio

C

B

A

View Into the Receiver

Detector Separation AC, DAC

Detector Separation AB, DAB

DAC / DAB is about 3.5 in RV series Receivers

~ 75 Fibers


TSI Incorporated

Error Sources and Validation Error Sources and Validation TechniquesTechniques

• Probe Volume Bias

• TSI’s 3rd Generation PVC Algorithm

• Mixed Mode Scattering

• Intensity Validation

• Phase Validation: “Diameter Difference”


TSI Incorporated

I

r

Sample Volume or Probe Sample Volume or Probe VolumeVolume

r(di)

A(di)A(di)

W

Defined by the Slit Defined by the Slit

dw


TSI Incorporated

1/2dw = ro

ID

I(di)m

2r(di)D

More in Next Slide

Probe Volume Probe Volume BiasBiasQuestion: Why does the sample volume depend on measured drop size?

Answer: Larger drops can pass through the beam anywhere and still produce enough light to be detected

Scattered Intensity:

Few mV up to 1000mV

This size and larger can be detected everywhere.

Typically 5 ~ 15um


TSI Incorporated

Bias is corrected for inside the Gaussian

beam waist.

All phase Doppler instruments suffer from

probe volume bias.

Probe Volume Probe Volume BiasBias

Bias can be corrected for

Small drops can only be detected in center region.

Only larger

particles detected

Bias can be corrected for

May not be detected


TSI Incorporated

Probe Volume Correction Probe Volume Correction TechniqueTechnique

• Large Drops: Probe volume defined by lower intensity limit

• Small Drops: Probe volume obtained from the cumulative distribution of path lengths

Path Length (m)

Path Length Distribution for 2 Runs

3.5E-04

Norm

aliz

ed C

ounts

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0 5.0E-05 1.0E-04 1.5E-04 2.0E-04 2.5E-04 3.0E-04

1011

Integrated


TSI Incorporated

Intensity ValidationIntensity Validation

But aren’t we throwing out good data? No.

Only TSI’s Intensity Validation can identify

the actual flow area:

A

B

C

B, C

A


TSI Incorporated

Intensity Validation Intensity Validation SettingsSettings

1/3 Dmax Method1/3 Dmax Method• Find Dmax from optics setup • Arrow indicates 1/3 of Dmax• Set slope of upper limit so

that it intersects saturation at 1/3 Dmax

• PMT voltage & laser power are adjusted so that the data comes close to upper limit

• Slope of Lower Limit is set to 1/10 Slope of Upper Limit

• This method is difficult to set up if only a small part of diameter range is being used

• See FAQ for more details• See Recent Support

presentation for more details


TSI Incorporated

Intensity Validation Intensity Validation SettingsSettings

D10 Stabilization MethodD10 Stabilization Method

• This method is particularly suitable when the system has an unusually wide diameter range and only a small part is being used

• See Manual for more details

D10

0

5

10

15

20

25

30

300 325 350 375 400 425 450 475 500 525 550 575

PMT Voltage

D1

0


TSI Incorporated

Intensity Validation on LDVIntensity Validation on LDVC

ount

Intensity

Rejects:Signals from large particles not tracking the flow

Sub-range out points above a threshold, eg Arrow


TSI Incorporated

Refraction

Reflection

Receiver

Reflection

Refraction

Mixed-Mode ScatteringMixed-Mode Scattering

Droplet is moving into the page

Reflection

InternalReflection


TSI Incorporated

Intensity ValidationIntensity Validation

Reflective Signals

Phase Wrap Region

MultipleParticlesRegion


TSI Incorporated

Reflected Signals from Large Reflected Signals from Large DropsDrops

• This issue often comes up with dense spray measurements

• Intensity validation may fail to reject these

• Their effect on mass flux is not significant

• Phase validation may be used to reject them via “Diameter Difference” check

Laser Beams

To Receiver

Gaussian Intensity Profile

y

z

Note that droplet is ‘large,’ non-uniformly illuminated,and just outside the waist


TSI Incorporated

Phase Validation: Phase Validation: Integer Integer Phase RatioPhase Ratio

Refraction

Reflection

Note that the ratio of Phase AC is 3x Phase AB

1

3

Phase AB

Phase AC

360

360

00


TSI Incorporated

Phase AB

Phase AC

360

360

00

Refraction

Reflection

Note that the ratio of Phase AC is now 3.5x Phase AB

1

3.5

Phase Validation: Non-iPhase Validation: Non-integer nteger Phase RatioPhase Ratio


TSI Incorporated

Phase ValidationPhase Validation

Phase AB

Phase AC

360

360

00

Indicated measurements would appear outside our 7% limit

Actual Data

Mismatch Limit, Typ 7%


TSI Incorporated

FlowSizer 2.0 SoftwareFlowSizer 2.0 Software

New Fitting Routines


TSI Incorporated

Measurement Case StudiesMeasurement Case Studies

• Pulsed Bio-Diesel and Common Rail diesel spray (2 cases)• Flux Profile of a DI Gasoline spray• Condensing flow at a turbine outlet• Mach 2 scramjet engine flow• Aircraft based hurricane measurements• Turbine engine combustor• Nasal Inhaler Spray


TSI Incorporated

PDPA Measurements by PDPA Measurements by FSA 4000FSA 4000

Pulsed Diesel Injector

100% Bio-Diesel Fuel


TSI Incorporated

High Density Diesel SprayHigh Density Diesel Spray

Velocity 1 Realtime

0 2.00x10 -3 4.00x10 -3 6.00x10 -30

24

48

72

96

120

Time Ch. 1 (sec)

Veloc

ity C

h. 1 (

m/se

c)

Courtesy CMT – Polytechnic Univ. ValenciaTSI-64

Particle Diameter Distribution

0 16 32 48 64 80

0.4

1.8

3.2

4.6

6.0

Diameter (um)

No

rma

lize

d D

iam

ete

r C

ou

nt

(%/u

m)

0

100

200

300

400

500

600

Pa

rticle

Co

nc

en

tratio

n 1

/(cc

*um

)

Uncorrected DiameterCorrected DiameterCorrected AreaCorrected VolumeParticle Con. per Bin


TSI Incorporated

Diameter Statistics

High Density Diesel SprayHigh Density Diesel Spray

Courtesy CMT – Polytechnic Univ. Valencia

PVC SpatialD10 (um)D20 (um)D30 (um)D32 (um)D43 (um)PhaseAB Mean (degree)PhaseAB RMS (degree)PhaseAC Mean (degree)PhaseAC RMS (degree)Size Data Rate (Hz)Size Valid CountEpsilon ExceptionDiameter ExceptionIntensity Invalid

16.41 16.07 16.3917.51 17.19 17.6018.55 18.25 18.7020.82 20.57 21.1123.05 22.7970.5430.04-18.78121.0451425000455405286

Extended Diameter Statistics

xqLWC (g/m3)Volume Flux X (cc/cm2 s)Volume Flux Y (cc/cm2 s)Volume Flux Z (cc/cm2 s)Volume 1 (%)Volume 10 (%)Volume 50 (%)Volume 90 (%)Volume 99 (%)Total Particle Conc.(1/cc)

23.643.9531.07760.05860.00000.00007.3913.3721.5429.1934.799762.7988


TSI Incorporated

Flux Profile of a G-DI SprayFlux Profile of a G-DI Spray

Excellent Repeatability


TSI Incorporated

Flux Profile of a Coolant Flux Profile of a Coolant SpraySpray

X Y Flux( )

A New Method for Minimizing Volumetric Flux Errors Associated with PDPA Measurements in the Dilute Region of Full Cone Pressure Swirl Atomizers, ICLASS 2006, Paper # 06-163


TSI Incorporated

High Density Condensing High Density Condensing FlowFlow

Diameter Measurement Statistics Raw PVCD10 (um) 1.35 2.08 D20 (um) 1.57 2.11 D30 (um) 2.14 2.26 D32 (um) 3.97 2.59

Coinc. Size Data Rate (Hz) 5737 Particle Conc.(1/cc ) 1,175,879

Waist Size 16umLaser Power ~4W


TSI Incorporated

High Speed FlowHigh Speed FlowGatetime 1 Histogram

0 0.467 0.933 1.4000

1000

2000

3000

4000

Gate Time Ch. 1 (usec)

Ga

te T

ime

Co

un

t C

h. 1

Diameter Histogram

0 13 27 400

50

100

150

200

Diameter (um)

Dia

met

er C

ou

nt

Vmean = 595m/sFreqmean = 118.8MHzValid Vel = 100%Valid Dia = 91.7%

Gate Timemean = 110nsecData Rate: Ch 1 = 55.8kHz, Ch 2 = 26kHz

Courtesy Dr. Kuo-Cheng LinThis work was sponsored by AFRL/Propulsion Directorate at Wright-Patterson Air Force Base


TSI IncorporatedPDPA Measurements in PDPA Measurements in Supersonic Wind Tunnel Supersonic Wind Tunnel

(Jet in Crossflow)(Jet in Crossflow)

Mach 1.94

• d0=0.5 mm

• q0=7

• GLR=5%

• x/d0=200

Lin, K.-C., Kennedy, P.J., Jackson, T.A., “Structures of Water Jets in a Mach 1.94 Supersonic Crossflow,” AIAA Paper 2004-0971, January 2004.This work was sponsored by AFRL/Propulsion Directorate at Wright-Patterson Air Force Base


TSI Incorporated

PDPA Measurement of a PDPA Measurement of a Spray in an Acoustic Spray in an Acoustic

FieldField

Courtesy Prof. R.I.Sujith and K. Gurubaran, Dept. of Aerospace Engineering, IIT-Madras, India

See AIAA paper 2008-1046 for more details.

Water Spray

Dual Speakers

Resonance Chamber


TSI Incorporated

PDPA Measurements in a PDPA Measurements in a Lean Low-NOx Aircraft Lean Low-NOx Aircraft

CombustorCombustor

Courtesy of Jonathan Colby and Georgia Institute of Technology

0 0.5 1 1.5 2 2.5 3 3.5 4

-2.5

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

X / Ro

Y /

Ro

D32

/ D

o

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

SMD with Combustion Lean Low NOx Combustor (GE CFM 56

Engine)


TSI Incorporated

Fuel Rate = 0.75g/sEq. Ratio = 0.4Tair = 380KTwall = 540K

Courtesy of Jonathan Colby, Georgia Institute of Technology

Lean Low NOx Combustor (GE CFM 56 Engine)

Cold Flow

Combustion

Courtesy of Jonathan Colby, Georgia Institute of Technology

LDV Measurements in PPL LDV Measurements in PPL CombustorCombustor


TSI Incorporated

PDPA Measurements in PDPA Measurements in Hurricane Hurricane

NOAA research aircraft N43RF

Courtesy of Prof. Bill Asher and Trina Litchendorf, APL, Univ of Washington

Hurricane Jeanne 9/25/04


TSI Incorporated

Nasal Inhaler Spray Nasal Inhaler Spray MeasurementsMeasurements

Measurements were made in externally triggered mode

100ms200ms300ms400ms

Diameter Histogram

0 10 20 30 400

50

100

150

200

Diameter (um)

Dia

met

er C

ou

nt

Realtime Diameter

0

20

40

60

80

100

120

0.00 0.10 0.20 0.30 0.40 0.50

Time (s)

Dia

me

ter

(um

)

Running Mean

Realtime Axial Velocity

0

1

2

3

4

5

6

0.00 0.10 0.20 0.30 0.40 0.50

Time (s)

Ve

loc

ity

(m

/s)

Running Mean

Time-averaged diameter


TSI Incorporated

Transient MeasurementsWhen an electronically triggered device is being measured, it is often interesting to look at time histories. You can use the “SyncPulse” input to act as an OPR signal with FlowSizer 2.0 and current FSA’s. EB option and OPR input is the best way to trigger FSA though.

Other CommentsOther Comments

Use of a TraverseIt is easy to create and run scans through the flow, with the Traverse GUI in FlowSizer. Scans can be saved, and edited in Excel.


TSI Incorporated

ConclusionsConclusions

• We have seen how the droplet scatters light• Fringe pattern is detected from three angles, resulting in

phase difference• Phase is linearly related to diameter• Intensity Validation works with Probe Volume

Correction (PVC) to give reliable results, even flux• Phase Validation provides backup to Intensity Validation• PDPA systems used in many applications, worldwide

Date post:	15-Jan-2016
Category:	Documents
Upload:	lisa-paternoster
View:	220 times
Download:	2 times

TSI Incorporated Copyright© 2008 TSI Incorporated Phase Doppler Particle Analyzer 2007 TSI LDV/PDPA...

Documents