Computational assessment of the effects of pre-chamber and piston geometries on the combustion characteristics of an optical pre-chamber engine

Xinlei Liu, Manuel Echeverri Marquez*, Sangeeth Sanal, Mickael Silva, Abdullah S. AlRamadan, Emre Cenker, Priybrat Sharma, Gaetano Magnotti, James W.G. Turner, Hong G. Im

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

Pre-chamber combustion (PCC) has the potential to extend the lean-burn limit in spark-ignition engines, which can promote engine efficiency and relieve the concern of emissions of nitrogen oxides. This work assessed the effects of pre-chamber (PC) and piston geometries on the combustion characteristics of an optical methane PCC engine with both experimental and computational approaches. Five active-type PCs with different volumes and nozzle diameters (12 nozzles distributed evenly in two layers) and two pistons (bowl and flat) were tested under lean-burn conditions. Multi-cycle pressure and heat release profiles, natural flame luminosity images, and OH* chemiluminescence images were measured and employed for CFD modeling validations. The PCs with the smaller nozzle diameter yielded more intensely-reacting jets from the upper layer of nozzles compared to the other PCs, attributed to the stronger gas choke there, which dramatically affected the flow fields. A larger PC volume allowed more air–fuel mixture to be trapped within the PC whose combustion then resulted in faster pressure buildup, which, however, led to higher heat transfer loss. Compared to the bowl piston, the flat piston generated a higher heat release rate during the late combustion period owing to the relatively longer jet propagation within the squish region.

Original languageEnglish (US)
Article number127659
JournalFuel
Volume341
DOIs
StatePublished - Jun 1 2023

Keywords

  • Jet flame
  • Natural Gas
  • OH* chemiluminescence
  • Optical engine
  • Pre-chamber combustion
  • Spark ignition

ASJC Scopus subject areas

  • General Chemical Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology
  • Organic Chemistry

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