Experimental study on spray break-up and atomization processes from GDI injector using high injection pressure up to 30MPa

摘要: Abstract This paper focuses on the influence of injection pressures up to 30 MPa single liquid jet break-up and atomization processes. For this purpose, a from multi-hole GDI injector has been characterized performing visualization PDPA (phase Doppler particle analyzer) experiments. Using thin sheet light generated by Nd:Yag laser capturing sequence development images with CCD camera, internal structure was visualized. In order quantify droplet diameter velocity, 2-D system were carried out in addition spray visualization. Analyzing result PDPA, including velocity distribution increasing pressure 30 MPa, elevated characterized. Our experimental results show existence leading edge observed at initial stage injection. phenomenon revealed relatively large droplets ahead main then disappeared quickly as lose momentum. Furthermore, for all pressures, unique ‘branch-like structure’ when fully developed. had many counter rotating branches related effect air-entrainment rapidly broken down into clusters droplets. Especially, increased pressure, time exhibit distance between two decreased. addition, based various we confirmed that plays key role break-up, but limit enhance also occurred. That is, 5 10 20 MPa led decrease SMD (Sauter mean diameter) linearly approximately 10 μm. However, an above 20 MPa, did not any significant reduction SMD.