연료분무 및 연소 2 : 연료 분사압력 및 분위기압력이 다공형 GDI 인젝터의 분무 특성에 미치는 영향 모델링

Abstract

The purpose of this study is to investigate the effect of injection pressure and ambient gas pressure on GDI spray characteristics. The CFD (Computational Fluid Dynamics) method is adopted to conduct more quantitative evaluation of spray atomization performance. A multi-dimensional KIVA-3V CFD code was implemented to simulate the two-dimensional spray behavior. KH-RT (Kelvin-Helmholtz, Reyleigh-Taylor) breakup model, evaporation model and droplet collision model were used to consider the real physical phenomena in calculation process. Meanwhile, the predicted results such as spray plume shape, penetration and SMD (Sauter Mean Diameter) results were validate with experimental results to verify the prediction accuracy. It was revealed that spray penetration length is decreased and spray vortex is formed near the nozzle hole as ambient gas pressure increased. The SMD was decreased as injection pressure is increased due to high aerodynamic force. On the whole, predicted results showed good agreement with experimental results.