Investigations on Low Pressure Gasoline Direct Injection for a Standard GDI Combustion System

Schmidt, Stephan; Joyce, Martin; Wall, Jonathan; Trattner, Alexander; Kirchberger, Roland; Eichlseder, Helmut

doi:10.4271/2010-32-0094

Cited by 7 publications

(6 citation statements)

References 2 publications

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“…Though intense charge motion and high in-cylinder turbulence are required with lower fuel injection pressures for good mixture formation, however, it was noted that the engine stability was not affected. 16 Engine stability was also not affected by a reduction in engine temperature. During a cold start, LPDI engine performance was not affected by a drop in pressure to 50 bar.…”

Section: Introductionmentioning

confidence: 97%

“…15 However, in recent years, there is a significant interest in utilising low-pressure direct-injection (LPDI) in GDI (Gasoline Direct Injection) engines so that they will become competitive to port fuel injection (PFI) engines. 16 LPDI can also reduce the cost and energy consumption of associated auxiliaries which is important in this segment. 11 Larger droplets formed with LPDI injection systems lead to higher oil dilution at cold engine conditions with high smoke emission.…”

Section: Introductionmentioning

confidence: 99%

“…17 SOI of 30 CAD was found to give an optimum value of efficiency and THC (total hydro-carbon) emission with a moderate amount of NOx (nitric oxide) emission. 16 Fuel injection pressure has a significant impact on engine performance and emissions at higher engine loads. THC emission was found to be the most sensitive to fuel injection pressure followed by smoke, CO (carbon monoxide) and NOx.…”

Section: Introductionmentioning

confidence: 99%

“…THC emission was found to be the most sensitive to fuel injection pressure followed by smoke, CO (carbon monoxide) and NOx. 16 Turbulence inside the cylinder increases with engine speed while the time available for the mixture preparation reduces with an increase in engine speed. These counteracting factors make the effect of speed barely significant.…”

Section: Introductionmentioning

confidence: 99%

“…These counteracting factors make the effect of speed barely significant. 16 The locations of spark plug and fuel injector were also found to influence the combustion stability. 20 The proximity of the spark plug with respect to incoming fuel spray further affects the combustion stability of the engine.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and computational studies on the effects of reduced fuel injection pressure and spark plug protrusion on the performance and emissions of a small-bore gasoline direct-injection engine

Jose

Mittal

Ramesh

2022

Proceedings of the Institution of Mechanical Engineers, Part D:

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Application of direct injection (DI) technology in small-bore engines, the type used in two- and three-wheelers, could improve their performance significantly. It is recognised that the use of high fuel injection pressure is beneficial in large-bore engines for a good mixture preparation. However, simple systems incorporated with low-pressure DI are desirable in small-engine segment of automobiles. Further, high fuel pressures will result in excessive wall wetting when cylinder dimensions are small. Extensive studies were carried out to investigate the minimum fuel injection pressure required for homogeneous and lean modes of operation in such small bore DI engine. The effect of spark plug protrusion in the combustion chamber was also investigated under the spray-guided configuration. Comprehensive experiments and CFD simulations were performed for estimating the engine efficiency, emissions, mixture preparation characteristics, fuel spray and fuel impingement on combustion chamber walls. Results have demonstrated that engine performance and emissions did not deteriorate when fuel injection pressure was reduced from 150 to 50 bar at full load. However, at very low pressures, like 20–30 bar, THC, CO and smoke emissions increased. Fuel injection pressure did not influence the lean limit, that is, equivalence ratio of about 0.77, but influenced the thermal efficiency at lean conditions. In order to attain high efficiency, under lean conditions, a minimum fuel pressure of 80 bar was required. The spark plug protrusion that resulted in a gap of 0.75 mm with respect to the incoming fuel spray cone has given the best engine performance, while higher protrusions affected the tumble flow and led to the stratification of charge near the spark plug, which resulted in elevated CO and smoke emissions. Hence, this work highlights that relatively lower direct injection pressures are suitable in small bore engines, which will impact the development of cost effective components for such applications.

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Section: Introductionmentioning

confidence: 97%