Emissions Characteristics of Military Helicopter Engines with JP-8 and Fischer-Tropsch Fuels

摘要

The rapid growth in aviation activities and more stringent U.S. Environmental Protection Agency regulationsnhave increased concerns regarding aircraft emissions, due to their harmful health and environmental impacts,nespecially in the vicinity of airports and military bases. In this study, the gaseous and particulate-matter emissions ofntwo General Electric T701C engines and one T700 engine were evaluated. The T700 series engines power the U.S.nArmy’s Black Hawk and Apache helicopters. The engines were fueled with standard military JP-8 fuel and werentested at three power settings. In addition, one of the T701C engines was operated on a natural-gas-derived Fischer–nTropsch synthetic paraffinic kerosene jet fuel. Test results show that the T701C engine emits significantly lowernparticulate-matter emissions than the T700 for all conditions tested. Particulate-matter mass emission indices rangednfrom 0.2–1.4 g/kg fuel for the T700 and 0:2–0:6 g=kg fuel for the T701C. Slightly higher NOx and lower COnemissions were observed for the T701C compared with the T700. Operation of the T701C with the Fischer–Tropschnfuel rendered dramatic reductions in soot emissions relative to operation on JP-8, due primarily to the lack ofnaromatic compounds in the alternative fuel. The Fischer–Tropsch fuel also produced smaller particles and slightnreductions in CO emissions.