Effect of Ethanol on Knock in Spark Ignition Gasoline Engines

Kenjiro Nakama, Jin Kusaka, Yasuhiro Daisho

Research output: Contribution to journalConference article

3 Citations (Scopus)

Abstract

This study examines the effects of ethanol content on engine performances and the knock characteristics in spark ignition gasoline engine under various compression ratio conditions by cylinder pressure analysis, visualization and numerical simulation. The results confirm that increasing the ethanol content provides for greater engine torque and thermal efficiency as a result of the improvement of knock tolerance. It was also confirmed that increasing the compression ratio together with increasing ethanol content is effective to overcome the shortcomings of poor fuel economy caused by the low calorific value of ethanol. Further, the results of one dimensional flame propagation simulation show that ethanol content increase laminar burning velocity. Moreover, the results of visualization by using a bore scope demonstrate that ethanol affects the increase of initial flame propagation speed and thus helps suppress knock.

Original languageEnglish
JournalSAE Technical Papers
Volume2008-September
DOIs
Publication statusPublished - 2008 Jan 1
EventSAE Small Engine Technology Conference and Exposition, SETC 2008 - Milwaukee, United States
Duration: 2008 Sep 92008 Sep 11

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ASJC Scopus subject areas

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

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