A Study of Gasoline-Alcohol Blended Fuels in an Advanced Turbocharged DISI Engine

Abstract

This work was concerned with evaluation of the performance and emissions of potential future biofuels during advanced spark ignition engine operation. The fuels prepared included three variants of gasoline, three gasoline-ethanol blends and a gasoline-butanol fuel altogether covering a range of oxygen mass concentrations and octane numbers to identify key influencing parameters. The combustion of the fuels was evaluated in a turbocharged multi-cylinder direct fuel injection research engine equipped with a standard three-way catalyst and an external EGR circuit that allowed use of either cooled or non-cooled EGR. The engine operating effects studied at both part and boosted high load conditions included fuel injection timing and pressure, excess air tolerance, EGR tolerance and spark retard limits. A number of blends were also mapped at suitable sites across the European drive cycle under downsized engine conditions. Relative in-vehicle fuel economies were then determined via drive cycle simulation and compared to a naturally aspirated gasoline PFI engine.

A Study of Alcohol Blended Fuels in an Unthrottled Single Cylinder Spark Ignition Engine

“…The spark timing and mass fraction burned data indicated that the higher ethanol content blends burned faster under both throttled and unthrottled conditions. This observation is in good agreement with laminar burning velocity correlations in the literature (36,37) and also recent observations by the currently reporting authors in a modern multi-cylinder turbocharged DI SI engine (27). Otherwise, the iso-octane incurred marginally lower indicated fuel consumption than the commercial gasoline case.…”

“…This topic so far appears to have been the subject of little research presented within the public domain. The nearest relevant publications readily available involve reduced part-load throttling with alcohol fuels via exhaust gas recirculation (26,27).…”

An Analysis of the Combustion Behavior of Ethanol, Butanol,Iso-Octane, Gasoline, and Methane in a Direct-Injection Spark-Ignition Research Engine

“…This example illustrates that results should not be assumed to carry over easily to various combustion systems, and that there are difficulties in drawing general conclusions from such data in the literature, when changes in hardware and operating strategies can easily change the outcome of a particular test in practice. Other recent studies with various types of injection systems for DISI engines presented results with a diversity of gasoline= ethanol and gasoline=butanol blends but did not focus on comparing pure ethanol and butanol fuels (Aleiferis et al, 2010b;Brewster, 2007;Cairns et al, 2009;Kapus et al, 2007;Wallner et al, 2009). The optical studies of Serras-Pereira et al (2008) with ethanol and butanol DI, using early injection for homogeneous engine operation, as well as that of Smith and Sick (2007) with ethanol and iso-butanol DI, using late injection for stratified operation, provided some useful insights, but did not focus on various fuel types and strategies over a large area of low-load engine conditions.…”

The competing chemical and physical effects of transient fuel enrichment on heavy knock in an optical spark ignition engine

“…However, the efficient distillation of crude oil produces similar amounts of gasoline and diesel fuel and European passenger diesel sales have now approached saturated levels [1]. The recent "dieselgate" scandal surrounding diesel engine emissions has also tarnished the reputation of diesel engines for automotive applications.…”