Institute for Environmental Research

Bleed Air Contaminant 

Particulate Measurements

Steven Eckels, Byron Jones, Garrett Mann, Shahin Amiri, Jacob Roth

Mechanical & Nuclear Eng., Kansas State University

&

Krishnan R Mohan, Clifford P. Weisel

Environmental and Occupational Health Sciences Institute, Rutgers 

University
Institute for Environmental Research

Bleed Air Contaminant 

Particulate Measurements

• Bleed air simulator measurement

– Phase 1

– Phase 2

• VIPR program

• Test stand turbine engine measurements
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BAS – Phase 1

• Particle size distribution from the simulator for 

the following conditions:

Point # Base Study 1 Study 2 Study 3 Study 4

Temp,

°C (°F)

Press,

kPa (psi)

Temp,

°C (°F)

Press,

kPa (psi)

Temp,

°C (°F)

Press,

kPa (psi)

Temp,

°C (°F)

Press,

kPa (psi)

Temp,

°C (°F)

Press,

kPa (psi)

1 No Heat 200 (29) 100 (212) 200 (29) 230 (445) 690 (100) 230 (445) 200 (29) 280 (535) 200 (29)

2 185 (365) 200 (29) 200 (392) 200 (29) 250 (490) 690 (100) — — 280 (535) 340 (50)

3 230 (445) 460 (67) 240 (464) 200 (29) 280 (535) 690 (100) 230 (445) 480 (70) 280 (535) 480 (70)

4 250 (490) 690 (100) 275 (527) 200 (29) 310 (590) 690 (100) 230 (445) 690 (100) 280 (535) 690 (100)

5 280 (535) 480 (70)

6 310 (590) 690 (100)
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Particle Measuring

Aerodynamic Particle Sizer

• TSI Model 3321

• Measures aerodynamic 

diameter by recording the 

time of flight of particles as 

they are accelerated 

through a nozzle.

• Particle size is binned into 

52 channels from 0.5μm to 

20 μm.

Condensation Particle Counter

• TSI Model 3781

• Measures particle 

concentration by optical 

counting.

• Water is deposited by 

condensation onto the 

particles to make them 

large enough to be detected 

optically.

• Particles as small as 6 nm 

are counted. There is no 

binning.
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Particle Measuring

Optical Particle Counter

• Climet Spectro 0.3

• Calculates particle size and 

concentration by measuring 

the intensity of light 

scattered by the particles.

• Particle size is binned into 

16 channels from 0.3μm to 

10μm.

Scanning Mobility Particle Sizer

• TSI 3496

• Uses ionization with electric 

field to separate particles by 

mobility

• Uses a CPC to count 

different size bands

• Size range from 10nm to 

532nm.
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Results

100 150 200 250 300 350

101

102

103

Temperature (°C)

Arithmetic Mean Diameter (nm)

APS

OPC

SMPS

Size distributions from base study
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Results

101 102 103

0

2

4

6

8

10

12

14

x 105

Diameter (nm)

Concentration (#/cm

3)

185°C

230°C
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BAS – Phase 2

• Particle Sizing

• FTIR analysis of gaseous contaminants

• Collection of contaminant samples with 

absorbent tubes
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Particle Measuring

Aerodynamic Particle Sizer

• TSI Model 3321

• Measures aerodynamic 

diameter by recording the 

time of flight of particles as 

they are accelerated 

through a nozzle.

• Particle size is binned into 

52 channels from 0.5μm to 

20 μm.

Scanning Mobility Particle Sizer

• TSI 3496

• Uses ionization with electric 

field to separate particles by 

mobility

• Uses a CPC to count 

different size bands

• Size range from 10nm to 

532nm.
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BAS Experimental Conditions

Temperature (C) Pressure (psia)

30 50 70 100

185

220

250

280

310
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SMPS 30 psia

nano meters
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SMPS 100 psia

nano meters
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APS 50 psia

micro meters
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APS 100 psia

micro meters
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Conclusions from BAS Measurements

• Bulk of particle counts below 300 nm

• Higher temperatures generate substantially 

more ultrafine particles, likely smoke 

generation

• Generation of increased ultrafine particles at 

elevated temperatures not likely tied to 

apparatus
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Bleed air contamination detector?

Ionization smoke detectors work well for d<300 nm
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Vehicle Integrated Propulsion Research (VIPR)

• Multi-year, multi phase NASA program 

• Other players include Air Force, Boeing, Pratt 

and Whitney, MAKEL, and the FAA

• Many objectives but overall focus is real time 

engine health monitoring

• Bleed air contaminant measurements a small, 

but important, piece of the program
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VIPR Test Bed

Boeing C-17 Globemaster III 
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VIPR Experimental Apparatus

Bleed Air System Test Rig
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VIPR Bleed Air Data
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VIPR Plans

• Anticipate next phase of measurements in 

early 2015

• ACER Participation???
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Test Stand Turbine Engine

• BAS simulator can reproduce pressure and 

temperature but not the same environment

• Turbine engine compressor is nearly adiabatic 

with vanes and high speed blades. All heating 

is due to compression.

• BAS uses non-adiabatic reciprocating piston 

compressor with after-heater.
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Test Stand Turbine Engine

• Are particle characteristics universal or 

specific to the bleed air apparatus?

• Are particle characteristics dependent upon 

the nature of the aerosol introduction?

• Real aircraft engines (e.g. VIPR) are the 

ultimate answer but very expensive and 

difficult to run experiments.

• Small engine can answer most questions at 

fraction of the cost.
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Allison T63
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Allison T63
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Measurement Equipment
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Lots of work to do before August
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