Fuel breakup near nozzle exit of high-pressure swirl injector for gasoline direct injection engine

Nobuyuki Kawahara, Eiji Tomita, Daisuke Kasahara, Takashi Nakayama, Mamoru Sumida

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)


Experimental investigations of fuel breakup very close to nozzle of practical high-pressure swirl injector, which is used in gasoline direct injection (GDI) engine, were carried out. In GDI engines, fuel is directly injected into cylinder therefore the spray characteristics and mixture formation are of primary importance. In this research, visualizations of primary spray formation process were demonstrated using a high-speed video camera (maximum speed: 1Mfps) with a long-distance microscope. Initial state and development of the spray were discussed under the different injection pressure condition. During the injection period, the length and thickness of the liquid sheet, which is produced from the nozzle exit, were measured using Ar-ion laser sheet and high-speed camera. Primary spray structure and behavior of liquid sheet, especially surface wave of liquid sheet, at nozzle exit were discussed using obtained images. Three main conclusions were drawn from this study. (1) It has been shown that the liquid fuel column without swirl motion was injected as a compact jet at the beginning of the injection. During the injection period, the spray indicates the quasi-steady state mode. (2) Liquid film sheet has a ligament structure. Using Ar-ion laser sheet and high-speed camera, length and thickness of the liquid sheet can be measured. Higher injection pressure causes thinner thickness and shorter length of liquid sheet. (3) Surface waves of liquid sheet can be recognized. Higher injection pressure makes larger wavelength of surface waves of liquid sheet of swirl injector.

Original languageEnglish
Title of host publication2004 SAE World Congress
PublisherSAE International
ISBN (Print)0768013194, 9780768013191
Publication statusPublished - 2004
Event2004 SAE World Congress - Detroit, MI, United States
Duration: Mar 8 2004Mar 11 2004


Other2004 SAE World Congress
Country/TerritoryUnited States
CityDetroit, MI

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering


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