Optical diagnostics of HCCI and low-temperature diesel using simultaneous 2-D PLIF of OH and formaldehyde

Leif Hildingsson*, Håkan Persson, Bengt Johansson, Robert Collin, Jenny Nygren, Mattias Richter, Marcus Aldén, Ryo Hasegawa, Hiromichi Yanagihara

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

15 Scopus citations


Simultaneous OH- and formaldehyde planar-LIF measurements have been performed in an optical engine using two laser sources working on 283 and 355 nm, respectively. The engine used for the measurements was a car Diesel engine converted to single-cylinder operation and modified for optical access. The fuel, n-heptane, was injected by a direct injection common rail system and the engine was also fitted with an EGR system. The engine was operated in both HCCI mode and Diesel mode. Due to the low load, the Diesel mode resulted in low-temperature Diesel combustion and because of limitations in maximum pressure and maximum rate of pressure increase of the optical engine, the Diesel mode was run at a higher EGR percentage than the HCCI mode to slow down the combustion. A third mode, pilot combustion, was also investigated. This pilot combustion is created by an injection at 30 CAD before TDC followed by a second injection just before TDC. The OH and formaldehyde LIF images were compared with the heat-release calculated from the pressure-traces. Analyses of the emissions, of for example NOx and HC, were also performed for the different operating modes.

Original languageEnglish (US)
StatePublished - Dec 1 2004
EventPowertrain and Fluid Systems Conference and Exhibition - Tampa, FL, United States
Duration: Oct 25 2004Oct 28 2004


OtherPowertrain and Fluid Systems Conference and Exhibition
Country/TerritoryUnited States
CityTampa, FL

ASJC Scopus subject areas

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


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