Potential of a Production DI Two-Stroke Engine Adapted for Range Extender and Motorcycle Applications

Abstract

<div class="section abstract"><div class="htmlview paragraph">The main purpose of this paper will be to investigate if a small snowmobile gasoline Direct Injected (DI) two-stroke engine has the potential to be adapted for two other types of applications: as a range extender (REX) for electric vehicles and for a motorcycle application.</div><div class="htmlview paragraph">For the REX application, the main requested specifications (NVH, lightweight, compactness, minimum production cost and easy maintenance), correspond well to the main features of DI 2-stroke engines. The potential of a modified production engine operating in part load ultra-low NOx Controlled Auto Ignition (CAI) to meet the Euro 6 emissions standards on the NEDC cycle has already been demonstrated in a previous paper. In the first part of this new paper, we will investigate which solutions can be used to maintain this potential with even stricter legislations based on Euro 6d, WLTP cycle and Real Driving Emissions (RDE).</div><div class="htmlview paragraph">In the second part of this paper, the feasibility of using the same production DI 2-stroke base engine for a motorcycle application will be studied. To meet the future Euro 4 and 5 motorcycle emissions standards on the new WMTC driving cycle, new combustion strategies have to be implemented. They are based on the use of CAI at part load and of the control of the air-fuel ratio at higher load combined with a 3-way catalyst aftertreatment technology.</div><div class="htmlview paragraph">The encouraging results achieved show that such small DI 2-stroke engine could be a very attractive candidate for a low emissions motorcycle application as well as for a range extender application in an electric vehicle.</div></div>

Energy recovery from landfill gas emissions using a stepped piston segregated scavenge engine

“…In terms of oxides of nitrogen emissions two-stroke cycle engines regularly exhibit significant advantage over equivalent comparable four-stroke engines as discussed by Furuhama and Kobayashi, 11 Zhang and Zhao, 12 Duret et al 13 and Mattarelli et al, 14 Benajes et al 15 and Hooper et al 16 Extremely low NOx emissions have been observed from two-stroke engines such as the Lotus Omnivore as reported by Blundell et al 11 and Turner et al 12 This engine operated with variable compression ratio with single digit ppm NOx emissions on 95RON gasoline with further research on bio-fuels indicating similarly low NOx emissions. NOx emissions recorded from experimental stepped piston engines 16 has shown that the engine type shares the advantage of low levels, however the results observed via modelling in this study, whilst showing reduced levels against the fourstroke engine model, do not show such a marked reduction.…”

“…In terms of two-stroke engines, little research appears to have been published. Much work has been conducted on bio-fuels as can be seen from the research reported by Misron et al 7 but little on LFG operation apart from the research of Doherty et al 8 A number of researchers have considered natural gas operation of two-stroke engines as evidenced by the work of Douville et al 9 and Darzi et al 10 Engines operating on the two-stroke cycle emit lower emissions of oxides of nitrogen (NOx) than comparable four-stroke cycle engines as demonstrated by the research of Furuhama and Kobayashi, 11 Zhang and Zhao, 12 Duret et al, 13 Mattarelli et al, 14 Benajes et al 15 and Hooper et al 16 Further reduced NOx emissions have been shown by the research of Blundell et al, 17 Turner et al 18 World NOx emissions, from whatever source emits them, can have a particularly adverse effect on global warming (Lammel and Graßl, 19 Collins et al 20 and Bray et al 21 ). Nitrous oxide, N 2 O, reduces ozone occurring in the stratosphere thereby detrimentally affecting the planet's ability to control warming.…”