AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Mode Specified Semi-volatile Chemical Composition in PM Emissions from a Commercial Gas Turbine Aircraft Engine
ZHENHONG YU, Michael Timko, Andreas Beyersdorf, Luke Ziemba, Edward Winstead, Bruce Anderson, Scott Herndon, Richard Miake-Lye, Aerodyne Research, Inc.
Abstract Number: 149 Working Group: Combustion
Abstract It has been known that non-volatile particulate matter (PM) emissions from commercial aircraft engines can have significant impacts on local air quality and human health. NASA’s Alternative Aviation Fuel EXperiment 1 (AAFEX 1) field measurement campaign was performed to characterize and quantify both volatile and non-volatile PM emissions from commercial gas turbine aircraft engines, with participants from eleven governmental agencies, universities, and companies.
In this study, we determined semi-volatile chemical compositions of nucleation/growth mode and soot mode particles in the engine exhausts at a variety of engine powers (4-100% thrust) with a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS). Organic and sulfate components of both nucleation/growth and soot mode particles, were observed, while burning the conventional Jet-A fuel. Nitrate components in both the nucleation/growth and soot modes were negligible from the measurements.
Organic species were dominant at idle, but the sulfate content became important with increasing engine power. The organic composition of the nucleation/growth mode particles decreases with increasing engine power, and that of the soot mode initially decreases with increasing engine power, but then slightly increases again above 45% engine thrust, probably due to the increasing contribution from lubrication oil emissions. Our results demonstrate that the organic PM at idle is mainly aromatic species; while at 85% thrust, lubrication oil dominates.
This study implies that organic emission indices (EIs) from the nucleation mode particles decrease with increasing engine power, similar to the emissions of gaseous UHCs; and sulfate EIs from the soot mode particles strongly correlate with the black carbon soot emissions. These results show that an appreciable amount of semi-volatile PM can be generated in the exhaust plumes from a commercial aircraft engine. Thus, volatile PM must be studied as carefully as non-volatile soot emissions to fully address local air quality and human health impacts of aviation.