Ignition Delay, Lift-off and Soot Luminescence in Diesel-Ethanol Spray Combustion

Abstract

To investigate the influence of ethanol blending in Diesel fuel on the spray combustion characteristics, experiments were carried out in an optically accessed high-pressure/high-temperature spray chamber. Three different fuels were investigated: (1) Diesel, based on the European EN590 standard; (2) E10 with 10 % ethanol and (3) E20 with 20 % ethanol. Gas conditions were kept at a constant gas density of 24.3 kg/m3 at a lower combusting temperature (550 °C, 57.3 bar) and a higher combusting temperature (600 °C, 60 bar). The experimental results showed that ignition delay and delay time of soot formation were increased as ethanol was blended in Diesel fuel. Less soot luminescence was observed and longer lift-off length was measured in Diesel-ethanol blends compared to pure Diesel.