Effect of nozzle geometry on atomization of transient spray from port fuel injector

The present paper reports an experimental investigation of the effect of nozzle geometry of port fuel injector PFI on exit flow velocity, the stability of primary spray behavior and spray droplet size. Several types of PFI with were tested. The investigation of exit flow velocity and stability (wavelength) of spray structure was performed using an ultra high-speed video camera (max. camera speed 1Mfps) with a long-distance microscope (whole image). The visualized experiments were carried out in a closed chamber at the atmospheric pressure. With back-lighting, the time-series images of the spray behavior were obtained. Using ultra high-speed camera with long-distance microscope and Barlow lens, droplet diameter could be visualized with high temporal resolution (magnified image). Experimental results of average exit velocity compared with NOZZLE FLOW model where experimental results of stability and droplet diameter compared with KH-RT breakup model. Experimental investigation showed that exit velocity, droplet diameter and stability (wavelength) influence by nozzle geometry.