Achievement of medium engine speed and load premixed diesel combustion with variable valve timing

Yutaka Murata, Jin Kusaka, Matsuo Odaka, Yasuhiro Daisho, Daisuke Kawano, Hisakazu Suzuki, Hajime Ishii, Yuichi Goto

Research output: Contribution to journalConference article

35 Citations (Scopus)

Abstract

A variable valve timing (VVT) mechanism was applied to achieve premixed diesel combustion at higher load for low emissions and high thermal efficiency in a light duty diesel engine. By means of late intake valve closing (LIVC), compressed gas temperatures near the top dead center are lowered, thereby preventing too early ignition and increasing ignition delay to enhance fuel-air mixing. The variability of effective compression ratio has significant potential for ignition timing control of conventional diesel fuel mixtures. At the same time, the expansion ratio is kept constant to ensure thermal efficiency. Combining the control of LIVC, EGR, supercharging systems and high-pressure fuel injection equipment can simultaneously reduce NOx and smoke. The NOx and smoke suppression mechanism in the premixed diesel combustion was analyzed using the 3D-CFD code combined with detailed chemistry. LIVC can achieve a significant NOx and smoke reduction due to lowering combustion temperatures (LTC: Low Temperature Combustion) and avoiding local over-rich regions in the mixtures, respectively.

Original languageEnglish
JournalSAE Technical Papers
DOIs
Publication statusPublished - 2006 Jan 1
Event2006 SAE World Congress - Detroit, MI, United States
Duration: 2006 Apr 32006 Apr 6

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ASJC Scopus subject areas

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

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