Spray Characterization of Gasoline Direct Injection Sprays Under Fuel Injection Pressures up to 150 MPa with Different Nozzle Geometries
Paper in proceedings, 2019

Maximum fuel injection pressures for GDI engines is expected to increase due to positive effects on emissions and engine-efficiency. Current GDI injectors have maximum operating pressures of 35 MPa, but higher injection pressures have yielded promising reductions in particle number (PN) and improved combustion stability. However, the mechanisms responsible for these effects are poorly understood, and there have been few studies on fuel sprays formed at high injection pressures.

This paper summarizes experimental studies on the properties of sprays formed at high injection pressures. The results of these experiments can be used as inputs for CFD simulations and studies on combustion behavior, emissions formation, and combustion system design. The experiments were conducted using an injection rate meter and optical methods in a constant volume spray chamber. Injection rate measurements were performed to determine the injectors’ flow characteristics. Spray imaging was performed using a high-speed video camera. Several spray properties such as the liquid spray penetration, spray plume angle, and the spray breakup point were determined as functions of the fuel injection pressure and injected fuel mass by image post-processing. The impact of fuel pressure on spray droplet size was also investigated using two-component Phase Doppler Interferometry.

Piezoelectric injectors for diesel engines were used with modified nozzles that produce sprays resembling those generated in gasoline engines. Experiments were performed with fuel injection pressures ranging from 20 to 150 MPa, and chamber pressures of 0.1 and 0.6 MPa. In addition, four different nozzles with three different nozzle configurations and either 6 or 10 holes were used to determine how hole geometry affects spray formation.

The study’s key findings are that increasing the fuel injection pressure advances spray breakup and creates smaller droplets, improving mixture formation and accelerating evaporation. The nozzle type and the ambient pressure both significantly affect aspects of spray behavior such as spray tip development.

spray imaging

Phase Doppler Interferometry

spray

GDI

high pressure

injector

Author

Akichika Yamaguchi

DENSO Corporation

Lucien Koopmans

Chalmers, Mechanics and Maritime Sciences, Combustion

Arjan Helmantel

Volvo Cars

Fabian Peng Karrholm

Denso Sales Sweden AB

Petter Dahlander

Chalmers, Mechanics and Maritime Sciences, Combustion

SAE Technical Papers

0148-7191 (ISSN)

SAE International Powertrains, Fuels and Lubiricants Meeting
San Antonio, USA,

Areas of Advance

Transport

Subject Categories

Applied Mechanics

Driving Forces

Innovation and entrepreneurship

DOI

10.4271/2019-01-0063

More information

Created

1/15/2019