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

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 \ub0C, 57.3 bar) and a higher combusting temperature (600 \ub0C, 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