41 0

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

Title
Experimental study on spray break-up and atomization processes from GDI injector using high injection pressure up to 30 MPa
Author
박성욱
Keywords
Gasoline direct injection (GDI); Phase Doppler particle analyzer (PDPA); Jet break-up processes; Branch-like structure; Sauter mean diameter (SMD); Air-entrainment
Issue Date
2014-02
Publisher
Elsevier B.V
Citation
International Journal of Heat and Fluid Flow February 2014, 45, 14-22
Abstract
This paper focuses on the influence of injection pressures up to 30MPa on single liquid jet break-up and atomization processes. For this purpose, a single jet from a multi-hole GDI injector has been characterized performing visualization and PDPA (phase Doppler particle analyzer) experiments. Using a thin sheet of light generated by a Nd:Yag laser and capturing a sequence of jet development images with a CCD camera, the internal structure was visualized. In order to quantify the droplet diameter and velocity, a 2-D PDPA system were carried out in addition to the spray visualization. Analyzing the images of the internal structure of jet and the result of PDPA, including droplet diameter and velocity distribution with increasing injection pressure up to 30MPa, the elevated injection pressure on a jet break-up and atomization was characterized. Our experimental results show the existence of a leading edge of the jet observed at the initial stage of injection. This phenomenon revealed relatively large droplets ahead of the main jet then disappeared quickly as lose the droplets momentum. Furthermore, for all injection pressures, unique ‘branch-like structure’ was observed when the jet was fully developed. This structure had many counter rotating branches related to the effect of air-entrainment and rapidly broken down into droplet clusters and droplets. Especially, as increased injection pressure, the time to exhibit the structure and distance between two branches were decreased. In addition, based on the results of droplet diameter and velocity distribution at various injection pressures, we confirmed that the injection pressure plays a key role in droplet break-up, but a limit in injection pressure to enhance droplet break-up also occurred. That is, increasing injection pressure from 5 to 10 to 20MPa led to a decrease in SMD (Sauter mean diameter) linearly by approximately 10μm. However, an injection pressure above 20MPa, did not result in any significant reduction in SMD.
URI
https://www.sciencedirect.com/science/article/pii/S0142727X13002166http://hdl.handle.net/20.500.11754/49550
ISSN
0142-727X
DOI
10.1016/j.ijheatfluidflow.2013.11.005
Appears in Collections:
COLLEGE OF ENGINEERING[S](공과대학) > MECHANICAL ENGINEERING(기계공학부) > Articles
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE