Experimental study on particle size distributions of an engine fueled with blends of biodiesel

The purpose of this study is to obtain the particle size distributions of an engine fueled biodiesel and its blends. A turbocharged DI diesel engine was tested on a dynamometer. A pump of 80 L/min and fiber glass filters with diameter of 90 mm were used to sample engine particles in exhaust pipe. Sampling duration was 10 minutes. Particle size distributions were measured by a laser diffraction particle size analyzer. Results indicated that higher engine speed resulted in smaller particle sizes and narrower distributions. The modes on distribution curves and mode variation were larger with dry samples than with wet samples (dry: around 10~12 μm vs. wet: around 4~10 μm). At low speed, Sauter mean diameter d₃₂ of dry samples was the biggest with B100, the smallest with diesel fuel, and among them with B20, while at high speed, d₃₂ the biggest with B20, the smallest with B100, and in middle with diesel. Median diameter d(0.5) also reflected the results. Except for 2000 r/min, d₃₂ of wet with B20 is the biggest, the smallest with diesel, and in middle with B100. The large mode variation resulted in increase of d₃₂.