Characterizing Particulate Matter Emissions From Aircraft Engines

2012 ◽  
Author(s):  
Anuj Bhargava ◽  
David Liscinsky ◽  
Randal McKinney ◽  
Bruce Anderson ◽  
Andreas Petzold ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Measurement Method ◽  
Mass Number ◽  
Response Times ◽  
Relevant Literature ◽  
Measurement Methods ◽  
Aircraft Engines ◽  
Number Count ◽  
Particulate Matter Emissions ◽  
Volatile Precursors

Research in the areas of particulate matter (PM) emissions impacts on both climate and human health are currently very active, however there are a large number of variables and response times. As a better understanding of the contribution of aviation PM emissions is developed, new aircraft engines will need to be designed for reduced PM emissions. In order to do this, measurement methods for different PM metrics like mass, number, size distribution, volatile precursors and composition need to be developed followed by measurements for existing engines to assess their environmental impact. Relevant literature will be reviewed to show that it is necessary to control emissions of nanometer-size particles from a total “number count” as well as a “mass” perspective. Several activities to develop a measurement method and evaluate its effectiveness will be discussed. The results are being used to develop standard measurement methods for aircraft PM emissions which will allow the design of lower emission combustors.

scholarly journals Post-Combustion Evolution of Soot Properties in an Aircraft Engine

2005 ◽  
Author(s):  
Pierre M. Dakhel ◽  
Stephen P. Lukachko ◽  
Ian A. Waitz ◽  
Richard C. Miake-Lye ◽  
Robert C. Brown
Keyword(s):  
Particulate Matter ◽  
Gas Phase ◽  
Cloud Condensation Nuclei ◽  
Aircraft Engine ◽  
Vapor Condensation ◽  
Gaseous Emissions ◽  
Aircraft Engines ◽  
Volatile Content ◽  
Particulate Matter Emissions ◽  
Microphysical Processes

Recent measurements have suggested that soot properties can evolve downstream of the combustor, changing the characteristics of aviation particulate matter (PM) emissions and possibly altering the subsequent atmospheric impacts. This paper addresses the potential for the post-combustion thermodynamic environment to influence aircraft non-volatile PM emissions. Microphysical processes and interactions with gas phase species have been modeled for temperatures and pressures representative of in-service engines. Time-scale arguments are used to evaluate the relative contributions that various phenomena may make to the evolution of soot, including coagulation growth, ion-soot attachment, and vapor condensation. Then a higher-fidelity microphysics kinetic is employed to estimate the extent to which soot properties evolve as a result of these processes. Results suggest that limited opportunities exist for the modification of the size distribution of the soot, its charge distribution, or its volatile content, leading to the conclusion that the characteristics of the turbine and nozzle of an aircraft engine have little or no influence on aircraft non-volatile emissions. Combustor processing determines the properties of soot particulate matter emissions from aircraft engines, setting the stage for interactions with gaseous emissions and development as cloud condensation nuclei in the exhaust plume.

Measurement of Volatile Particulate Matter Emissions From Aircraft Engines Using a Simulated Plume Aging System

2011 ◽  
Author(s):  
Jay Peck ◽  
Michael T. Timko ◽  
Zhenhong Yu ◽  
Hsi-Wu Wong ◽  
Scott C. Herndon ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Aircraft Engine ◽  
Ambient Conditions ◽  
Sampling System ◽  
Engine Exhaust ◽  
Precursor Material ◽  
Particulate Matter Emissions ◽  
Engine Testing ◽  
Volatile Precursors ◽  
The Impact

Aircraft exhaust contains nonvolatile (soot) particulate matter (PM), trace gas pollutants, and volatile PM precursor material. Nonvolatile soot particles are predominantly present at the engine exit plane, but volatile PM precursors form new particles or add mass to the existing ones as the exhaust is diluted and cooled. Accurately characterizing the volatile PM mass, number, and size distribution is challenging due to this evolving nature and the impact of local ambient conditions on the gas-to-particle conversion processes. To accurately and consistently measure the aircraft PM emissions, a dilution and aging sampling system that can condense volatile precursors to particle phase to simulate atmospheric evolution of aircraft engine exhaust has been developed. In this paper, field demonstration of its operation is described. The dilution/aging probe system was tested using both a combustor rig and on-wing CFM56-7 engines. During the combustor rig testing at NASA Glenn Research Center, the dilution/aging probe supported formation of both nucleation/growth mode particles and soot coatings. The results showed that by increasing residence time, the nucleation particles become larger in size, increase in total mass, and decrease in number. During the on-wing CFM56-7 engine testing at Chicago Midway Airport, the dilution/aging probe was able to form soot coatings as well as nucleation mode particles, unlike conventional 1-m probe engine measurements. The number concentration of nucleation particles depended on sample fraction and relative humidity of the dilution air. The performance of the instrument is analyzed and explained using computational microphysics simulations.

Comparative Study on Various Methods for Measuring Engine Particulate Matter Emissions

2018 ◽  
Author(s):  
Z. Gerald Liu ◽  
Devin R. Berg ◽  
James J. Schauer‡
Keyword(s):  
Particulate Matter ◽  
Mass Measurement ◽  
Chemical Species ◽  
Measurement Methods ◽  
Particulate Emissions ◽  
Engine Exhaust ◽  
Particulate Emission ◽  
Low Emission ◽  
Particulate Matter Emissions ◽  
Particulate Mass

Studies have shown that there are a significant number of chemical species present in engine exhaust particulate matter emissions. Additionally, the majority of current world-wide regulatory methods for measuring engine particulate emissions are gravimetrically based. As modern engines produce increasingly lower particulate mass emissions, these methods become less and less stable and have high levels of measurement uncertainty. In this study, a characterization of mass emissions from engines with a range of particulate emission levels was made in order to gain a better understanding of the variability and uncertainty associated with common mass measurement methods, as well as how well these methods compare with each other. Two gravimetric mass measurement methods and a reconstructed mass method were analyzed as part of the present study. The results have shown that each of the mass measurement methods analyzed compare well at higher emission levels, but show significant disparity at the ultra-low emission levels commonly seen from modern diesel engines. Additionally, at ultra-low emission the uncertainty in the measurement becomes large, thus reducing confidence in the accuracy of the measurement. Based upon these findings, it would be difficult to justify a comparison between any two gravimetric measurement methods and it may be more appropriate to perform a reconstruction of the particulate mass due to a lower susceptibility to measurement error.

Measurement of Volatile Particulate Matter Emissions From Aircraft Engines Using a Simulated Plume Aging System

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Jay Peck ◽  
Michael T. Timko ◽  
Zhenhong Yu ◽  
Hsi-Wu Wong ◽  
Scott C. Herndon ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Aircraft Engine ◽  
Ambient Conditions ◽  
Sampling System ◽  
Engine Exhaust ◽  
Precursor Material ◽  
Particulate Matter Emissions ◽  
Engine Testing ◽  
Volatile Precursors ◽  
The Impact

Aircraft exhaust contains nonvolatile (soot) particulate matter (PM), trace gas pollutants, and volatile PM precursor material. Nonvolatile soot particles are predominantly present at the engine exit plane, but volatile PM precursors form new particles or add mass to the existing ones as the exhaust is diluted and cooled. Accurately characterizing the volatile PM mass, number, and size distribution is challenging due to this evolving nature and the impact of local ambient conditions on the gas-to-particle conversion processes. To accurately and consistently measure the aircraft PM emissions, a dilution and aging sampling system that can condense volatile precursors to particle phase to simulate the atmospheric evolution of aircraft engine exhaust has been developed. In this paper, a field demonstration of its operation is described. The dilution/aging probe system was tested using both a combustor rig and on-wing CFM56-7 engines. During the combustor rig testing at NASA Glenn Research Center, the dilution/aging probe supported formation of both nucleation/growth mode particles and soot coatings. The results showed that by increasing residence time, the nucleation particles become larger in size, increase in total mass, and decrease in number. During the on-wing CFM56-7 engine testing at Chicago Midway Airport, the dilution/aging probe was able to form soot coatings along with nucleation mode particles, unlike conventional 1-m probe engine measurements. The number concentration of nucleation particles depended on the sample fraction and relative humidity of the dilution air. The performance of the instrument is analyzed and explained using computational microphysics simulations.

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