Air Motion Induced by Ultra-High Injection Pressure Sprays for Gasoline Direct Injection Engines
Artikel i vetenskaplig tidskrift, 2020

The fuel injection pressures used in gasoline direct injection (GDI) engines have increased in recent years to improve fuel efficiency and reduce emissions. Current GDI engines use injection pressures of up to 350 bar, and there is evidence that even higher fuel injection pressures could yield further improvements in atomization. Higher injection pressures could also improve mixture formation by increasing the spray velocity; however, the research with higher injection pressures over 1000 bar is limited due to a limit of mechanical components. This manuscript summarizes experimental investigations into the effect of injection pressure, injection mass, and nozzle shape on spray-induced air motion with ultrahigh injection pressure over 1000 bar. Fuel sprays were generated at a range of injection pressures with different injection masses and nozzle geometries, and Particle Image Velocimetry (PIV) was performed using a Charge-coupled device (CCD) camera and an Nd:YAG (neodymium-doped yttrium aluminium garnet) laser to characterize the vector fields in the surrounding air and the rate of air entrainment into the sprays. Sprays generated with higher injection pressures and injection masses induced stronger large-scale air motion: an injection pressure of 1500 bar with an injection mass of only 5 mg caused almost the same amount of air entrainment as an injection pressure of 200 bar with an injection mass of 27 mg. However, the spray-induced air motion dissipated within 5 ms after the end of injection (EOI) in all cases. The air entrainment rate was also increased by using a divergent nozzle rather than a convergent one. Interactions between the spray and the surrounding air are thus strengthened by using a high injection pressure and a divergent nozzle.

Injector

High pressure

Spray

GDI

Nozzle shape

Air entrainment

PIV

Författare

Akichika Yamaguchi

DENSO Corporation

Lucien Koopmans

Chalmers, Mekanik och maritima vetenskaper, Förbränning och framdrivningssystem

Ayolt Helmantel

Volvo Cars

Johan Dillner

DENSO Sweden AB

Petter Dahlander

Chalmers, Mekanik och maritima vetenskaper, Förbränning och framdrivningssystem, Förbränningsmotorer och framdrivningssystem

SAE International Journal of Fuels and Lubricants

1946-3952 (ISSN)

Vol. 13 3 223-235

Ämneskategorier

Energiteknik

Atom- och molekylfysik och optik

Den kondenserade materiens fysik

DOI

10.4271/04-13-03-0014

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Senast uppdaterat

2021-01-31