AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Comparison of PM Emissions in Expanding Exhaust Plumes from Gas Turbine Engines burning Conventional and Alternative Fuels
PREM LOBO, Donald Hagen, Max Trueblood, Philip Whitefield, Missouri University of Science and Technology
Abstract Number: 466 Working Group: Combustion
Abstract Concern is growing about the emissions from aircraft operations and their impact on local air quality and health effects. The primary products of aviation fuel combustion are gas phase species such as NOx, UHC, CO, SOx, CO2, H2O, and Particulate Matter (PM). As the exhaust plume expands, mixes with ambient air, and cools, volatile compounds present in the gas phase at the engine exit plane, begin to condense on existing particles and form new particles. The nature of these secondary particles depends fuel composition, ambient meteorological conditions, and plume age. Recent studies focusing on the use of alternative fuels in gas turbine engines have shown that alternative fuels significantly reduce primary PM emissions. However, the impact of the emissions from aircraft engines burning these alternative fuels on the environment as the emissions evolve post combustion has not been fully explored.
The comparison of PM Emissions in an expanding exhaust plume from gas turbine engines burning conventional, Fischer-Tropsch (FT) and Hydroprocessed Esters and Fatty Acids (HEFA) fuels is presented here. The emissions data was acquired during two major field campaigns: the Sheffield APU Study conducted in Sheffield, UK in September 2009, and the Alternative Aviation Fuels EXperiment (AAFEX) II conducted in Palmdale, CA in March 2011. For the Sheffield APU Study, emissions were sampled 10m downstream of an auxiliary power unit where the total PM number and mass emissions were found to increase relative exit plane measurements and were attributed to gas-to-particle conversion in the exhaust plume. For the AAFEX II study, PM size, using a differential mobility spectrometer and soluble mass fraction (SMF), using a hygroscopic-tandem differential mobility analyzer were measured 143m downstream of a CFM56-2C1 gas turbine engine. SMF was found to increase with fuel sulfur content and engine power condition, and decrease with particle diameter.