Experiment study on spray structure of a multi-hole GDI injector

The spray structure and its developments generated by a multi-hole gasoline direct injection (GDI) have been investigated and discussed. Experiments were carried out on a constant volume chamber (CVC) rig. The effects of injection pressure, ambient pressure and ambient temperature were examined using high speed CCD camera. Images were processed by a specific program based on MatLAB. The spray tip penetration and overall spray cone angle were then analyzed and discussed. It was found that the spray penetration was mostly affected by ambient pressure and by injection secondly, while the ambient temperature slightly affected them both.