Abstract
Spray characteristics of diesel mini sac nozzles are unsteady during initial and end stages of injection. In this paper, modeling the effect of needle lift on sac internal flow and high dispersion spray due to sac vortex flow during low needle lift at the initial and end stages of injection are reported. The injection velocity with the sac pressure and the sac vortex energy and the injection droplet diameter generated by the liquid film thickness of high-dispersion spray are estimated. The model results were compared with experimental results obtained from fuel spray visualization. The results show that the proposed injection model can reproduce the unsteady dispersion characteristics of spray during low needle lift.
