Experimental investigation of performance and soot emissions of oxygenated fuel blends in a small aero engine

Abstract

Recent studies show that mixing jet fuel with oxygenated fuels has an impact on exhaust gas soot formation. Soot particles are an environmental hazard with an impact on air quality around airports, and possibly influencing ice crystal nucleation, leading to contrail and ice cloud (cirrus) formation. These ice clouds significantly warm up the atmosphere by reflecting heat radiation back to Earth and, at the same time, being transparent to incoming sunlight. Many investigations concentrate on reducing aviation’s CO2 footprint, but only a few account for reducing soot emissions in aero engines. This study examines the potential of blending Jet A-1 with oxygenated fuels to decrease soot particle formation in aero engines. For this, blends with 5 vol% and 20 vol% of ethanol, and 5 vol% of a polyoxymethylene dimethyl ether 3–5 mix (OME3-5 mix) are investigated in an Allison 250-C20B turboshaft engine with the help of a condensation particle counter (CPC). The results show tendencies in soot particle reduction, which, in most cases, is larger than the volumetric percentage of the oxygenated fuel within the blend.