Abstract
This work explores pathways to achieve diesel-like, high-efficiency combustion with stoichiometric 3-way catalyst compatible spark ignition (SI). A high stroke-to-bore engine design (1.5:1) with cooled exhaust gas recirculation (EGR) and high compression ratio (rc) was used to improve engine efficiency by up to 30% compared with a production turbocharged gasoline direct injection spark ignition engine. To achieve efficiency improvements, engine experiments were coupled with computational fluid dynamics simulations to guide and explain experimental trends between the original engine and the high stroke-to-bore ratio design (1.5:1). The effects of EGR and late intake valve closing (IVC) and fuel characteristics are investigated through their effects on knock mitigation. Direct injection of 91 RON E10 gasoline, 99 RON E0 gasoline, and liquified petroleum gas (i.e., propane/autogas) were evaluated with geometric rc ranging from 13.3:1 to 16.8:1. Engine experiments demonstrated 47% gross thermal efficiency, and 45% net thermal efficiency at stoichiometric engine operation, at up to 17 bar IMEP and 2000 r/min with 16.8:1 rc.
| Original language | English |
|---|---|
| Journal | SAE Technical Papers |
| Volume | 2020-April |
| Issue number | April |
| DOIs | |
| State | Published - Apr 14 2020 |
| Event | SAE 2020 World Congress Experience, WCX 2020 - Detroit, United States Duration: Apr 21 2020 → Apr 23 2020 |
Funding
This research was supported by the DOE 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. A special thanks to DOE program managers Kevin Stork, Michael Weismiller, and Gurpreet Singh for funding this work.
