Effects of in-nozzle flow and low-pressure zone on spray targeting of multi-hole gasoline direct injection injector

Article Energy & Fuels

A zonal secondary break-up model for 3D-CFD simulations of GDI sprays

F. Berni et al.

Summary: An alternative secondary break-up model is proposed based on Reitz-Diwakar, with zonalization of break-up regimes and model parameters as functions of operating conditions. Calibrated and validated on different GDI injectors, the proposed model shows satisfactory agreement with experiments compared to ReitzDiwakar and KHRT models applied with default calibration constants.

FUEL (2022)

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Article Energy & Fuels

Local momentum flux measurement: An effective way for GDI spray targeting in flash boiling conditions

Andrea Cavicchi et al.

Summary: Fuel injection and spray development are crucial for gasoline direct injected engines to achieve high thermal efficiency and limit pollutant emissions. Detecting the actual spray targeting is challenging due to the wide range of injection operating conditions. Conventional optical techniques often fail to provide quantitative data about the inner spray structure. In this study, imaging and momentum local distribution measurement were used to investigate the spray evolution under flashing and non-flashing conditions. The momentum distribution maps proved to be an effective way to analyze the spray targeting, flow distribution, and overall spray evolution.

FUEL (2022)

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Article Thermodynamics

Spray collapse characteristics of practical GDI spray for lateral-mounted GDI engines

Heechang Oh et al.

Summary: This study investigated spray collapsing and plume merging processes using a lateral-mounted gasoline direct injection (GDI) injector with a practical 'triangular' spray pattern. High-speed diffusive back illumination extinction imaging followed by computed tomography reconstruction was employed to understand the spatiotemporal plume dynamics under engine-like conditions. The experiments revealed that a triangular 6-hole spray pattern commonly used in lateral-mounted GDI engines is prone to plume merging and spray collapse due to the close proximity of centrally located plumes. Variations in air entrainment and local pressure were identified as the dominant factors affecting the timing and position of spray collapse.

INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER (2022)

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Article Physics, Applied

Distribution of Liquid Mass in Transient Sprays Measured Using Laser-Plasma-Driven X-Ray Tomography

Diego Guenot et al.

Summary: By using laser-plasma-driven x rays, we are able to reveal the three-dimensional structure of a highly atomizing water spray, and the computer tomography helps retrieve the local liquid volume distribution and its spatial variation.

PHYSICAL REVIEW APPLIED (2022)

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Article Thermodynamics

Split injection flash boiling spray for high efficiency and low emissions in a GDI engine under lean combustion condition *

Zhe Sun et al.

Summary: This study explores the use of flash boiling atomization to achieve a more homogeneous fuel-air mixture for lean combustion in a single cylinder engine. Imaging methods and traditional tests were utilized to evaluate engine performance, showing improved combustion efficiency and emission performance under flash boiling conditions, particularly with split injection schemes.

PROCEEDINGS OF THE COMBUSTION INSTITUTE (2021)

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Article Energy & Fuels

Development and validation of an improved atomization model for GDI spray simulations: Coupling effects of nozzle-generated turbulence and aerodynamic force

Yaoting Li et al.

Summary: By coupling the WF turbulent primary breakup theory with the KH and RT aerodynamic instability theories, a WF-KH-RT model was developed and successfully applied to predict the spray morphology, STP, and SMD in GDI injectors. The study showed that increasing specific model parameters like B1, Csx, and CRT could enhance STP and SMD in most conditions. Additionally, the aerodynamic effect becomes stronger while the turbulent effect weaker as the ratio of fuel density to ambient density decreases.

FUEL (2021)

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Article Energy & Fuels