There is increasing demand for a finer atomization of fuel spray in order to improve the engine performance and mileage, reduce exhaust emissions and then improve the transient response. . We are improving the shape of holes in order to enhance finer atomization. It is especially important to reveal the spray break-up process and droplet diameter quantitatively for a better development of holes shape.
In this paper, we set our focus on a multiple-hole nozzle and developed a quantitative visible analysis method to investigate the spray break-up process and droplet diameter. With this method, index of the relationship between break-up process and droplet diameter was defined. And by re-shaping the holes and by arrangement of the holes, the break-up process and droplets diameter were investigated.