Mass Measurements for Gas Turbine Engine Exhaust

Prem Lobo, Donald Hagen and Philip Whitefield

Cambridge Particle MeetingMay 18, 2007

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Overview

�Regulatory requirements�Measurement Campaigns�Good understanding of size, number and

shape�Direct mass measurement �Examples from recent studies�Future Work

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Growth of Commercial Air Traffic� PM from aircraft gas turbine engines during all phase o f

operation represents a unique source of a criteria pollu tant as defined by the Clean Air Act

� Particulate matter (PM) represents a direct threat to pu blic health and contributes to visibility degradation…North Eastern States Coordinated Air Use Management , 2003

� 10 of the 50 Largest Public Use Airports in PM10 NAA/Maintenance Areas; Approximately 31 will be in P M2.5 areas…DOT ACAIS Airport Database and EPA Green Book for N onattainment Areas

� EPA - the health costs of fine PM are hundreds of tim es greater than those of NOx on a per pound basis.

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Regulatory Requirements

� International Civil Aviation Organization (ICAO) requires the reporting of the “smoke number” for engine certification (SAE ARP 1179 Rev C)

� PM reduction design strategies in the last 20 years have been so effective that most current/advanced engines in operation today have virtually negligible smoke numbers throughout their operational envelope

� Negligible smoke numbers, however do not ensure negligible PM emissions

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Regulatory Requirements

�First Order Approximation (FOA3)�CAEP developed, accepted, and supported� Identified scientific expressions for each driver of

aircraft PM emissions…�non-volatile, fuel sulfur content, fuel organics

� INTERIM METHODOLOGY- FOA will become obsolete once a fully validated & verified database of PM EIs represents the current flying fleet is prepared�Measurements are the gold standard

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Measurement Campaigns

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Measurements with the DMS500

Wey et al., 2007 “Overview on the Aircraft Particle Emissions eXperiment (APEX)”, accepted Journal of Propulsion & Power

Lobo et al., 2007, “Physical characterization of aerosol emissions from a CommercialGas Turbine Engine – Project APEX”, accepted Journal of Propulsion & Power

Whitefield et al., 2006, “PM emissions from advected plumes at the Oakland International Airport”, Transport, Atmosphere, and Climate Conference, Oxford UK

Hagen et al., 2006, “Volatile Aerosol in Gas Turbine Emissions”, Proc. 10th-Combustion Generated Nanoparticles Conf., Zurich, Switzerland

3 6 10 18 32 56 100

178

316

562

1000

196.0224.0 252.0

280.0308.0 336.0

364.0

0.E+00

2.E+14

4.E+14

6.E+14

8.E+14

1.E+15

1.E+15

1.E+15

2.E+15

2.E+15

2.E+15

dEIn

/dlo

gDp

#/kg

_fu

Particle Diameter (nm)Time (s)

dEIn/dlog(dp) (#/kg_fu)

1.0E+12 2.2E+13 4.6E+14 1.0E+16

1000

500

200

100

50

20

10

5

Par

ticle diameter

(nm)

419

14

18

53

13

21

1937

10

14

13

34

9

916 94

1941

34

309

9

12

0

25

50

75

100

125

150

175

200

225

250

9/27/2004 9/28/2004 9/29/2004 COMPOSITE

EIn

(1e1

5/kg

f)

BR715x1-30 CF34-xx1 CF6-80xx CFM56-xxx JT8D-xxx PW2037

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Direct Mass Measurements

�Good understanding of size, number and shape

�Need a direct mass measurement�Effective density of jet engine exhaust

particles�Previous work with TEOM, DMM

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Data from TOEM

� Large data scatter at high power due to high vibration� Takes relatively long (4-5 mins) to stabilize after change in

engine condition

Corporan et al., 2004, “CFM56 Engine PM Mass Measurements using a TEOM”, APEX Conference, Cleveland OH, November 2004

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Lab Experiments

Dekati Mass Monitor (DMM)

Cambustion DMS500

Dekati Mass Monitor (DMM) is a real-time instrument for automotive particulate mass emission measurements

Moisio, M. Niemelä, V. “Device for Continuous Measurement of Density and Mass Concentration of Vehicle Exhaust Aerosol”, IAC 2002.

Goal:

To examine the performance of a Cambustion DMS500 –DMM combination to determine the effective density of diesel exhaust particles

DMM gives mass concentration

DMS500 gives number concentration which can be converted into a volume concentration

The ratio of DMM mass conc. to DMS500 volume conc. gives the effective density of the particles

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Density as function of particle size: Diesel Agglomerates

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Concentration Profile and Size Distributions

0

10

20

30

40

50

60

70

80

90

100

55000 55400 55800 56200 56600 57000

Time (SAM)

Mas

s µ

g/m

3

DMS500 (M15) DMS500 (M21) DMM

0.0E+00

5.0E+04

1.0E+05

1.5E+05

2.0E+05

2.5E+05

3.0E+05

1 10 100 1000Dp (nm)

dN/d

logD

p

0.0E+00

5.0E+10

1.0E+11

1.5E+11

2.0E+11

1 10 100 1000Dp (nm)

dM/d

logD

p

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Effective Density

�Effective density

= DMM mass concDMS500 volume conc

= 0.8 ± 0.1 g/cc

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

NASA Glenn Sampling Study –November 2006

Dekati Mass Monitor (DMM)

Cambustion DMS500

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Change in DMM set points for application to jet engine exhaust

�Fractal dimension changed from 2.5 to 3Schmid et al., 2004 “Methodology for Particle Characterization in the Exhaust Flows of Gas Turbine Engines”, Aerosol Sci. Technol.

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Size Distributions

0.0E+00

5.0E+06

1.0E+07

1.5E+07

2.0E+07

2.5E+07

3.0E+07

1 10 100 1000Dp (nm)

dN/d

logD

p

0.0E+00

2.0E+11

4.0E+11

6.0E+11

8.0E+11

1.0E+12

1.2E+12

1.4E+12

1.6E+12

1 10 100 1000

Dp (nm)

dM/d

logD

p

Number-based size distribution

Mass-based size distribution

16.91nm21.88 nm

28.71nm

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Concentration Profiles

0

100

200

300

400

500

600

39250 39350 39450 39550 39650 39750 39850 39950

Time (SAM)

Mas

s µ

g/m

3

DMM DMS500 (M21)

0

100

200

300

400

500

600

43759 43809 43859 43909 43959 44009 44059 44109 44159

Time (SAM)

Mas

s µ

g/m

3

DMM DMS500 (M21)

Mean particle size = 18.6 nm

Density = 1.34 g/cc

Engine power setting = idle

Mean particle size = 21 nm

Density = 1.47 g/cc

Engine power setting = 30%

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Density vs. Particle Size

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

0 10 20 30 40 50 60 70 80 90 100

Dp (nm)

Eff

ectiv

e D

ensi

ty (g

/cc)

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Conclusions/Future Work

�DMS500-DMM technique to determine effective density

�Jet engine exhaust particle density �More data acquired at a recent test

involving a military engine

UMR Center of Excellence for Aerospace Particulate Emissions Reduction Research

Acknowledgements

Partnership for AiR

Transportation Noise

and Emission Reduction

Partnership for AiR

Transportation Noise

and Emission Reduction

An FAA/NASA/TC-sponsored Center of Excellence