Effect of elliptical and circular GDI injectors on spray impingement characteristics

The application of elliptical injector will not only increase the atomization quality, but also reduce spray tip penetration, which has the potential to avoid wall wetting. However, so far the research on the effect of elliptical GDI nozzle on impinging spray is seldom reported. In this study, A GDI nozzle with circular and elliptical cross section shapes was employed to study the spray impingement characteristics through VOF-spray one way coupling method. The results revealed that the elliptical spray has shorter penetration as compared to circular spray, and the circular spray impingement time is earlier than the elliptical spray. Additionally, the spray rebound height of the circular spray was larger than that of the elliptical spray at the initial injection progress, while the elliptical spray rebound height became higher at the end of the injection. Furthermore, the elliptical spray impingement wall film mass and area were always smaller as compared with circular spray, and the injection pressure showed a negative influence on wall film mass. Finally, the average film thickness of the spray-wall impingement for an elliptical nozzle is observed to be reduced by 10.3% compared to that of a circular nozzle. Increasing the injection pressure is helpful to decrease the average wall film thickness.