Experimental Analysis and Modeling of Ethanol-Biodiesel-Diesel Blends Injection Behavior

Fuel injection properties, including the injection rate (temporal aspects) and spray behavior (spatial aspects), play a crucial role in the combustion efffciency and emissions of diesel engines. TTis study investigates the effects of different ethanol-biodiesel-diesel (EBD) blends on the injection performance in diesel engines. Experimental tests are conducted to examine key injection parameters, such as spray penetration distance, spray cone angle, and droplet size, alongside an analysis of coupling leakage. TTe main ffndings are as follows: (1) TTe injection behavior of ethanol and diesel differs signiffcantly. TTe addition of ethanol reduces the density, viscosity, and modulus of elasticity of the fuel mixture. While the injection advance angle, penetration distance, and Sauter mean diameter show minimal changes, the spray cone angle and coupling leakage increase notably. TTese alterations may disrupt the “fuelair-chamber” matching characteristics of the original engine, potentially affecting performance. (2) In contrast, the injection performance of biodiesel is more similar to that of diesel. As biodiesel content increases, the density, viscosity, and modulus of elasticity of the blended fuel also grow. TTough changes in injection timing, penetration distance, and spray cone angle remain minimal, the Sauter mean diameter experiences a slight increase. TTe “air-fuel chamber” compatibility of the original engine is largely unaffected, though fuel atomization slightly deteriorates. Blending up to 20% biodiesel and 30% ethanol with diesel effectively compensates for the shortcomings of using single fuels, maintaining favorable injection dynamics while enhancing lubrication and sealing performance of engine components.