An experimental study of injection and spray characteristics of diesel and gasoline blends on a common rail injection system

The injection and spray characteristics of diesel and gasoline blends are investigated on a common rail injection system. The injection rate, fuel spray evolution process (tip penetration distance, spray cone angle, projected spray area and relative brightness intensity contour) and microscopic droplet features are analyzed. The results show that diesel and gasoline blends have higher volumetric injection rates, earlier starts of injection and shorter injection delays, but little variances are observed in the mass injection rates for different test fuels. Increased gasoline proportion in the test blends causes slightly decreased spray tip penetration distance but increased spray cone angle. Also, more smaller-size droplets are observed in the fuel jet of the diesel and gasoline blends, indicating that the spray breakup and atomization processes are promoted.