Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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Numerical Analysis of Flow Characteristic of Residual Gas due to Changes in Valve Timings during an Idle Operation in an SI Engine

가솔린 기관의 공회전 시 밸브 타이밍 변경에 따른 잔류가스 유동 변화에 관한 해석적 연구

  • Lee, Joon-Ho (Graduate School of Automotive Engineering, Kookmin University) ;
  • Kim, Duk-Sang (Graduate School of Automotive Engineering, Kookmin University) ;
  • Baik, Doo-Sung (Department of Mechanical and Automotive Engineering, Kookmin University) ;
  • Cho, Yong-Seok (Department of Mechanical and Automotive Engineering, Kookmin University)
  • 이준호 (국민대학교 자동차공학전문대학원) ;
  • 김득상 (국민대학교 자동차공학전문대학원) ;
  • 백두성 (국민대학교 기계자동차공학부) ;
  • 조용석 (국민대학교 기계자동차공학부)
  • Published : 2006.11.01
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Abstract

Residual gas fraction in a combustion process is very crucial to improve combustion and cyclic variations. Especially, the residual gas fraction is strongly affected by backflow of the residual gas during the valve overlap period in an idle operation. Therefore, it is one of the most interesting that valve timings can affect flow characteristics of gas exchange process, especially during idle operation. This analysis investigates residual gas fraction with respect to valve timing changes which is critical for combustion efficiency and engine performance. Flow characteristics of residual gas by changing intake and exhaust valve timing are calculated by CFD methodology during an idle operation in an SI engine. It is analyzed that retarded EVO and advanced IVO results in the increase of valve overlap period and consequently, residual gas fraction. Futhermore, changes in IVO have stronger effects on variation of residual gas fraction.

Keywords

References

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