Ignition Sensitivity Study of Partially Premixed Combustion by Using Shadowgraphy and OH∗ Chemiluminescence Methods

Mohammad Izadi Najafabadi*, Nico Dam, Bart Somers, Bengt Johansson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Partially Premixed Combustion (PPC) is a promising combustion concept for future IC engines. However, controllability of PPC is still a challenge and needs more investigation. The scope of the present study is to investigate the ignition sensitivity of PPC to the injection timing at different injection pressures. To better understand this, high-speed shadowgraphy is used to visualize fuel injection and evaporation at different Start of Injections (SOI). Spray penetration and injection targeting are derived from shadowgraphy movies. OH∗ chemiluminescence is used to comprehensively study the stratification level of combustion which is helpful for interpretation of ignition sensitivity behavior. Shadowgraphy results confirm that SOI strongly affects the spray penetration and evaporation of fuel. However, spray penetration and ignition sensitivity are barely affected by the injection pressure. There is a critical SOI range, in which a significant amount of fuel is trapped in the crevice volume. Injection in this critical range has a negative influence on the combustion efficiency and ignition sensitivity. Impingement of liquid fuel on the piston crown advances the combustion phasing by providing higher levels of stratification. Moreover, results of combustion stratification study show that stratification level has an inverse correlation with combustion phasing of PPC for late injections.

Original languageEnglish (US)
JournalSAE Technical Papers
StatePublished - 2016
Externally publishedYes

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering


Dive into the research topics of 'Ignition Sensitivity Study of Partially Premixed Combustion by Using Shadowgraphy and OH∗ Chemiluminescence Methods'. Together they form a unique fingerprint.

Cite this