Abstract
Prior research studies have investigated a wide variety of gasoline compression ignition (GCI) injection strategies and the resulting fuel stratification levels to maintain control over the combustion phasing, duration, and heat release rate. Previous GCI research at the US Department of Energy's Oak Ridge National Laboratory has shown that for a combustion mode with a low degree of fuel stratification, called "partial fuel stratification"(PFS), gasoline range fuels with anti-knock index values in the range of regular-grade gasoline (~87 anti-knock index or higher) provides very little controllability over the timing of combustion without significant boost pressures. On the contrary, heavy fuel stratification (HFS) provides control over combustion phasing but has challenges achieving low temperature combustion operation, which has the benefits of low NOX and soot emissions, because of the air handling burdens associated with the required high exhaust gas recirculation rates. This work investigates HFS and PFS combustion, efficiency, and emissions performance on a single-cylinder, medium-duty engine with a regular-grade gasoline (91 research octane number) at 1,200 rpm, 4.3 bar, and 3.0 nominal gross indicated mean effective pressure operating points with boost levels similar to those in a medium-duty diesel application. Authority of combustion phasing with main injection timing sweeps for HFS and second injection timing sweeps and fuel split sweeps for PFS are shown. In addition, this work is discussed in the context of previous findings with a light-duty diesel platform, and next steps and future direction for this work are presented.
| Original language | English |
|---|---|
| Journal | SAE Technical Papers |
| Issue number | 2021 |
| DOIs | |
| State | Published - Sep 21 2021 |
| Event | SAE 2021 Powertrains, Fuels and Lubricants Digital Summit, FFL 2021 - Virtual, Online, United States Duration: Sep 28 2021 → Sep 30 2021 |
Funding
Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This research was supported by the Department of Energy’s (DOE’s) Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office and used resources at the National Transportation Research Center, a DOE-EERE User Facility at Oak Ridge National Laboratory. The authors would gratefully like to thank the U.S. DOE Vehicle Technologies Office Program Managers Michael Weismiller and Gurpreet Singh for the support and guidance for this work. The authors would like to thank the generous support from Cummins, including Tim Lutz and many others, for supplying the engine used for this study and providing support for the machining of the cylinder head for flush mount pressure transducers. The authors would also like to thank Infineum for supplying the R655 lubricity additive used in this study. Special thanks to Steve Whitted, Scott Palko, Martin Wissink, and Chloe Lerin at Oak Ridge National Laboratory for supporting the design and build of the single-cylinder engine setup used for this study and to Flavio Chuahy for generating the graphic used in . 1