2017 年 83 巻 847 号 p. 16-00406
This paper describes about improvement of spray characteristics of the nozzle for a direct injection Diesel nozzle, which excellent spray characteristics is obtained. The purpose of this study is to develop high-dispersion injection nozzle for direct injection Diesel engine that is able to achieve lean combustion based on requirements of some automobile makers. In this study, effects of the pitch circle diameter and existence of inclination of the nozzle hole of the designed atomization enhancement nozzle on atomization characteristics were investigated. It was cleared that in case of the multi-hole nozzle with inclination angle of 45 degrees at the nozzle hole, breakup length becomes short about 20 % and spray angle becomes large about three times compared with the nozzle without inclination angle of the nozzle hole. Moreover, disintegration behavior of spray and atomization characteristics has been considerably improved.