Applicability of Ionization Current Sensing Technique with Plasma Jet Ignition Using PreChamber Spark Plug in a Heavy Duty Natural Gas Engine

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding


This article deals with study of ionization current sensing
technique's signal characteristics while operating with pre-chamber spark plug to achieve plasma jet ignition in a 6
cylinder 9 liter turbo-charged natural gas engine under EGR
and excess air dilution. Unlike the signal with conventional
spark plug which can be divided into distinct chemical and
thermal ionization peaks, the signal with pre-chamber spark
plug shows a much larger first peak and a negligible second
peak thereafter. Many studies in past have found the time of
second peak coinciding with the time of maximum cylinder
pressure and this correlation has been used as an input to
combustion control systems but the absence of second peak
makes application of this concept difficult with pre-chamber
spark plug. However, it has been observed that the first peak
is very strong and does not deteriorate much even under lean
operation and hence ion current signal integral can be used to
calculate real time combustion stability parameters for
combustion control systems. The correlation between the
coefficient of variation (COV) of indicated mean effective
pressure (IMEP) and ion current integral for operation at 5,
12 and 18 bar IMEP load under stoichiometric and diluted
operation with EGR and excess air is presented in this article.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering


  • Internal Combustion Engine, Natural Gas, Pre-chamber, Ignition
Original languageEnglish
Title of host publicationSAE Technical Paper
PublisherSociety of Automotive Engineers
Number of pages11
Publication statusPublished - 2012
Publication categoryResearch
EventSAE 2012 International Powertrains, Fuels & Lubricants Meeting - Malmo, Sweden
Duration: 2012 Sep 182012 Sep 20

Publication series

NameSAE Technical Paper Series
PublisherSAE International
ISSN (Print)0148-7191


ConferenceSAE 2012 International Powertrains, Fuels & Lubricants Meeting