AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Morphology of Particles Produced by Aviation Gas Turbines
Hugo Tjong, STEVEN ROGAK, Jason Olfert, Tyler Johnson, Jonathan Symonds, Kevin Thomson, Gregory Smallwood, University of British Columbia
Abstract Number: 724 Working Group: Combustion
Abstract Forty seven TEM grids containing particulate emission from aviation jet engines were produced as part of an effort to verify the practicability and robustness of the working draft nvPM ARP methodology defined by the SAE E-31 Committee. Grids were collected coincident with other particulate instrument measurement over a range of engine loads.
Images from the grids show that particulate emission from a jet engine has different characteristics compared to the emission from internal combustion engines. Whereas the PM emission produced by ICE dominated by open aggregate structure with minimum VOC concentration, most of the grids collected from a jet engine display substantial traces of VOC which exist in forms of droplets, mixed with EC (identified by typical fractal soot morphology) and an oily film on the surface of the TEM grid. There were minor quantities of unidentified particles including some with needle-like shapes.
The morphology of the EC shows a large variation in terms of primary particle diameter (dp), aggregate size and radius of gyration. The dp variation was found consistently across all grids while the aggregate size and radius of gyration were found to vary grid by grid.
A CPMA-DMS system was also used to measure the effective density of aircraft particulate. The density ranged from 600 to 1100 kg/m3 and was particle size and engine loading dependent. These results also supported the presence of volatile material with the denuded density being lower than the undenuded. By fitting the density distribution with a power law, the mass mobility exponent was determined to be 2.7 to 2.9 or near spherical morphology.
Laser Induced Incandescence measurements were taken simultaneously; trends with loads will be compared with those in the TEM and CPMA measurements.