Thermal efficiency improvement of a lean-boosted spark ignition engine by multidimensional simulation with detailed chemical kinetics

Ratnak Sok, Jin Kusaka, Yasuhiro Daisho, Kei Yoshimura, Kenjiro Nakama

Research output: Contribution to journalArticle

3 Citations (Scopus)


This paper aims to improve thermal efficiency of spark ignition engine by numerical calculation with detailed chemistry. Experimental results from a four-stroke-single-cylinder engine are compared with that of simulations. It is experimentally found that peak efficiency is achieved at lean-limit combustion under excess air ratio λ=1.6. Due to engine output power loss, further investigations are conducted under lean-boost operations. The best condition of the lean-boost mode is at λ=1.3 and 150 kPa boosted pressure (abs). To further improve the efficiency without power loss, simulations are conducted under lean-boost combustion with dilution rate, high engine swirl, and high knock resistant fuel.

Original languageEnglish
Pages (from-to)97-104
Number of pages8
JournalInternational Journal of Automotive Engineering
Issue number4
Publication statusPublished - 2015



  • Detailed chemical kinetics [A1]
  • Heat engine
  • Numerical calculation
  • Spark ignition engine

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Human Factors and Ergonomics

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