Influence of fuel injection strategies on efficiency and particulate emissions of gasoline and ethanol blends in a turbocharged multi-cylinder direct injection engine

Abstract

The effects of a broad range of fuel injection strategies on thermal efficiency and engine-out emissions (CO, total hydrocarbons, NOx and particulate number) were studied for gasoline and ethanol fuel blends. A state-of-the-art production multi-cylinder turbocharged gasoline direct injection engine equipped with piezoelectric injectors was used to study fuels and fueling strategies not previously considered in the literature. A large parametric space was considered including up to four fuel injection events with variable injection timing and variable fuel mass in each injection event. Fuel blends of E30 (30% by volume ethanol) and E85 (85% by volume ethanol) were compared with baseline E0 (reference grade gasoline). The engine was operated over a range of loads with intake manifold absolute pressure from 800 to 1200 mbar. A combined application of ethanol blends with a multiple injection strategy yielded considerable improvement in engine-out particulate and gaseous emissions while maintaining or slightly improving engine brake thermal efficiency. The weighted injection spread parameter defined in this study, combined with the weighted center of injection timing defined in the previous literature, was found well suited to characterize multiple injection strategies, including the effects of the number of injections, fuel mass in each injection and the dwell time between injections.

A phenomenological modelling framework for particle emission simulation in a direct-injection gasoline engine

“…However, due to the difficulties involved with measurements of different particle sources, for example, the quantification of optical measurements, the pathways are not fixed yet, that is, the calibration of the pathways is an elementary first step of application. To raise the pathways to a higher physical degree, particle sources should be measured even more differentiated by combining new methods to improve the separation of effects 49,50 and the proposed pathway of the spray-wall interaction at the walls of the combustion chamber is to be realised. In addition to measurements, a set of 3D-CFD simulations is necessary to that end.…”

Mechanisms of fuel injector tip wetting and tip drying based on experimental measurements of engine-out particulate emissions from gasoline direct-injection engines

“…[11][12][13] Some operating strategies and design criteria 14 can help reduce and sometimes eliminate fuel-rich zones, such as late fuel injection or multiple fuel injection events. 12,15,16 However, one surface wetting mechanism that cannot be avoided by injection strategy and is not well understood is injector tip wetting. Injector tip wetting occurs when the fuel injection event creates liquidphase fuel films or droplets on the tip of the fuel injector.…”

A comparative analysis of knock severity in a Cooperative Fuel Research engine using binary gasoline–alcohol blends

“…[23][24][25] In recent years, research on the behavior of ethanolgasoline blends in SI engines has been numerous. Exhaust gas emissions, 26,27 combustion efficiency, [27][28][29] octane number increase and knock mitigation, 22,[29][30][31][32] or its use with stratified charge SI strategies are some of the most studied fields. 33 Cooney et al 22 studied knock resistance for various ethanol-gasoline blends at different concentrations (pure gasoline, E20, E40, E60 and E84), including variations in CR and ignition time.…”