Fuel Spray Evaporation and Mixture Formation Processes of Ethanol/Gasoline Blend Injected by Hole-Type Nozzle for DISI Engine

Ethanol is regarded as the promising alternative fuel for gasoline to meet the strict low emission standard for spark ignition engines. In this study, the spray mixture formation process for different ethanol blended fuels, including E0 (gasoline), E85 (85% volume of ethanol and 15% volume of gasoline) and E100 (ethanol), has been evaluated using hole-type nozzle by the measurement of Laser Absorption Scattering (LAS) technique in a constant volume vessel. Based on the principle of LAS, the quantitative vapor and liquid phase distribution from different ethanol blended fuel can be obtained by the light extinction regime. Aiming to analyze the effect of mixture formation and evaporation for different components of blended fuel or pure gasoline and ethanol, the vapor distribution of gasoline was determined by using p-xylene, which had similar physical properties to gasoline, especially higher boiling temperature components, and higher absorption for ultraviolet. Likewise, the vapor behavior of ethanol was determined by using methylethyketone (MEK). The result shows that the evaporation of E100 is better than E85 and E0 corresponded to the order of fuel volatility, while the spray penetration reduces in the sequence of E0, E85 and E100 due to the higher volatility resulting in the increased spray volume and resistance of the ambient gas. The evaporation of E85 lies between E0 and E100 in terms of the saturated pressure curves, and the p-xylene in the blended fuel vaporizes faster than pure p-xylene.