Developmental Study on High-Dispersion Diesel Injection Nozzle (1st Report, Effects of Geometric Shape of Atomization Enhancement Nozzle on Atomization Characteristics of Spray)

The purpose of this study is to develop the nozzle, which is able to obtain the spray with high-dispersion and high-penetration under the low-injection pressure. Moreover, it is to improve spray characteristics of a direct injection Diesel nozzle using the atomization enhancement nozzle developed in the previous study. In this paper, the effects of geometric shape and measurement of the enlarged atomization enhancement nozzle on atomization of the spray and atomization characteristics were investigated. The discharge coefficient, the break up length and the spray angle were measured in variation of the injection pressures up to 1.5 MPa. The results show that the spray, which spread of the spray is large and the breakup length is short, was obtained using the nozzle with the optimum measurement conditions. Moreover, when this nozzle was applied to an injector with needle, the breakup length becomes short and the spray angle becomes large, the high-dispersion spray was obtained at the low-injection pressure.