Investigation into Occurrence of Megaknock and Auto-Ignition in GTDI Engines

The performance of boosted gasoline engines is limited at high loads by knock, stochastic Low Speed Pre-Ignition, and Megaknock. An investigation has been carried out on the occurrence of abnormal combustion and megaknock in a 1.6 L GTDI engine with the aim to determine the causes of such phenomena. A classification of abnormal combustion events and causes is presented in order to facilitate a consistent terminology. The experiments specifically focus on the effects of exhaust residual gas on occurrence of megaknock in multi-cylinder engines. The results showed that while a misfire will not lead to megaknock, a very late combustion in one cycle, in one cylinder may lead to megaknock in the following cycle in the same or adjacent cylinder. Additionally, a recently developed multi-zone model was used to analyze the role of residual gas on auto-ignition. It was found that residual gas from a late combustion event may in fact lead to auto-ignition in the following cycle; the composition of the residual gas and the presence of partially burned hydrocarbon species were found to be critical.

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01657222
  • Record Type: Publication
  • Source Agency: SAE International
  • Report/Paper Numbers: 2017-01-0690
  • Files: TRIS, SAE
  • Created Date: Mar 30 2017 10:03AM