Mechanism study of scavenging process and its effect on combustion characteristics in a boosted GDI engine

Yejian Qian, Zhen Gong, Yuan Zhuang, Chunmei Wang and Peng Zhao

Energy, 2018, vol. 165, issue PA, 246-266

Abstract: The scavenging process is helpful to suppress super-knock in a 4-stroke turbocharged gasoline direct injection engine because it can reduce in-cylinder thermal load and clear the suspending residual particles from previous cycles. This paper investigated the effects of dual variable valve timing on scavenging and combustion process by simulation and experimental study. The simulation results showed that the scavenging process improved with the advance of intake valve timing and the retard of exhaust valve timing. When the valve overlap duration was the same, the early occurrence of valve overlap was helpful to the scavenging process. The longer the valve overlap duration was the better the scavenging process would be. When exhaust valve timing was fixed, spark timing retarded with the advance of intake valve timing, nevertheless, the mixture mass, basic specific fuel consumption rate, combustion duration, and exhaust temperature increased with the advance of intake valve timing. In two early intake valve timing conditions, when exhaust valve timing was retarded, the mixture mass, basic specific fuel consumption, exhaust temperature raised, combustion duration and the length of ignition delay shortened. In three late intake valve timing conditions, the combustion characteristics were unchanged with the postponement of exhaust valve timing. The effect of dual variable valve timing on scavenging and combustion process was similar. Intake valve timing played a determinate role in the combustion performance of gasoline direct injection engine. The optimized scavenging process could lower the super-knock frequency and improve combustion characteristics.

Keywords: Scavenging process; Combustion characteristics; Dual variable valve timing; Gasoline direct injection (search for similar items in EconPapers)
Date: 2018
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0360544218318413
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:energy:v:165:y:2018:i:pa:p:246-266

DOI: 10.1016/j.energy.2018.09.077

Access Statistics for this article

Energy is currently edited by Henrik Lund and Mark J. Kaiser

More articles in Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().