A centrifugal particle mass analyzer and a modified differential mobility spectrometer were used to measure the mass and mobility of particulate matter emitted by CFM56-5B4/2P, CFM56-7B26/3, and PW4000-100 gas turbine engine sources. The mass-mobility exponent of the particulate matter from the CFM56-5B4/2P engine ranged from 2.68 to 2.82, whereas the effective particle densities varied from 600 to 1250 kg/m3, depending on the static engine thrust and sampling methodology used. The effective particle densities from the CFM56-7B26/3 and PW4000-100 engines also fell within this range. The sample was conditioned with or without a catalytic stripper and with or without dilution, which caused the effective density to change, indicating the presence of condensed semivolatile material on the particles. Variability of the determined effective densities across different engine thrusts, based on the scattering about the line of best fit, was lowest for the diluted samples and highest for the undiluted sample without a catalytic stripper. This variability indicates that the relative amount of semivolatile material produced was engine thrust dependent. It was found that the nonvolatile particulate matter, effective particle density (in kilograms per cubic meter) of the CFM56-5B4/2P engine at relative thrusts below 30% could be approximated using the particle mobility diameter (dme in meters) with 11.92d(2.76-3) me.
Bibliographical noteFunding Information:
This research would not have been possible without the financial support of the European Aviation Safety Agency (EASA) contract no. EASA.2010.FC10 Specific Contract Sample III — SC02 and the Swiss Federal Office of Civil Aviation project “Particulate Matter and Gas Phase Emission Measurement of Aircraft Engine Exhaust.” The contributions of Cambustion Ltd., Green Aviation Research and Development Network, MDS Aero Support Corporation, Natural Sciences and Engineering Research Council of Canada, and Alberta Innovates-Technology Futures were also significant to this research. B. Brem thanks the financial support of the Swiss Federal Laboratories for Materials Science and Technology EMPA postdoctoral fellowship. Special thanks go to Frithjof Siegerist and his team at SR Technics for engine operation and test cell facility access.
Copyright © 2014 by the American Institute of Aeronautics and Astronautics, Inc.