High-speed LIF imaging for cycle-resolved formaldehyde visualization in HCCI combustion

J. Olofsson*, H. Seyfried, M. Richter, M. Aldén, A. Vressner, A. Hultqvist, Bengt Johansson, K. Lombaert

*Corresponding author for this work

Research output: Contribution to conferencePaperpeer-review

6 Scopus citations


High-speed laser diagnostics was utilized for single-cycle resolved studies of the formaldehyde distribution in the combustion chamber of an HCCI engine. A multi-YAG laser system consisting of four individual Q-switched, flash lamp-pumped Nd:YAG lasers has previously been developed in order to obtain laser pulses at 355 nm suitable for performing LIF measurements of the formaldehyde molecule. Bursts of up to eight pulses with very short time separation can be produced, allowing capturing of LIF image series with high temporal resolution. The system was used together with a high-speed framing camera employing eight intensified CCD modules, with a frame-rate matching the laser pulse repetition rate. The diagnostic system was used to study the combustion in a truck-size HCCI engine, running at 1200 rpm using n-heptane as fuel. By using laser pulses with time separations as short as 70 μs, cycle-resolved image sequences of the formaldehyde distribution were obtained. Thus, with this technique it is possible to follow the formaldehyde formation and consumption processes within a single cycle. The combustion evolution was studied in terms of the rate and spatial structure of formaldehyde formation and consumption for different engine operating conditions, e.g. different stoichiometries. Also, the impact on the rate of heat-release was investigated.

Original languageEnglish (US)
StatePublished - Dec 1 2005
Event2005 SAE World Congress - Detroit, MI, United States
Duration: Apr 11 2005Apr 14 2005


Other2005 SAE World Congress
Country/TerritoryUnited States
CityDetroit, MI

ASJC Scopus subject areas

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


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