Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
권호 표지

Numerical Analysis for Prediction of the Residual Gas Fraction, Volumetric Efficiency and Pumping Loss with Continuous Variable Valve Lift System in an SI Engine

가변밸브 작동기구를 적용한 가솔린 기관의 잔류가스분율, 체적효율, 펌핑손실 예측을 위한 해석적 연구

  • Cho, Yong-Seok (Department of Mechanical and Automotive Engineering, Kookmin University) ;
  • Lee, Seang-Wock (Department of Mechanical and Automotive Engineering, Kookmin University) ;
  • Jang, Ik-Kyoo (Graduate School of Automotive Engineering, Kookmin University) ;
  • Park, Jung-kwon (Graduate School of Automotive Engineering, Kookmin University) ;
  • Yoon, Yu-Bin (Graduate School of Automotive Engineering, Kookmin University) ;
  • Park, Young-Joon (Graduate School of Automotive Engineering, Kookmin University) ;
  • Kim, Hyun-Chul (Korea Automotive Technology Institute) ;
  • Na, Byung-Chul (Korea Automotive Technology Institute)
  • 조용석 (국민대학교 기계자동차공학부) ;
  • 이성욱 (국민대학교 기계자동차공학부) ;
  • 장익규 (국민대학교 자동차공학전문대학원) ;
  • 박정권 (국민대학교 자동차공학전문대학원) ;
  • 윤여빈 (국민대학교 자동차공학전문대학원) ;
  • 박영준 (국민대학교 자동차공학전문대학원) ;
  • 김현철 (자동차부품연구원) ;
  • 나병철 (자동차부품연구원)
  • Received : 2009.03.13
  • Accepted : 2009.09.06
  • Published : 2010.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

To satisfy the needs on fuel economy and engine performance, continuous variable valve lift systems are applying to engines. In the CVVL system, fuel economy can be improved by reducing pumping loss during the induction process, and engine performance can be also improved by controlling volumetric efficiency and the residual gas fraction. Because the residual gas fraction directly affects volumetric efficiency, engine performance, combustion efficiency and emissions in SI engines, controlling residual gas fraction is one of the important things in engine development process. This analysis investigates the residual gas fraction and volumetric efficiency with changes of intake valve lifts and intake valve timings. In this study, unsteady state solutions were solved during exhaust and induction processes. Results show variation of the residual gas fraction and volumetric efficiency by changing intake valve timing and lift. Decreasing intake valve lift leads to increase the residual gas fraction and to decrease volumetric efficiency.

Keywords

References

  1. T. Sugiyama, R. Hiyoshi, S. Takemura and S. Aoyama, "Technology for Improving Engine Performance using Variable Mechanisms," SAE 2007-01-1290, 2007.
  2. S. Kiga, Y. Mae, Y. Akasaka and K. Tomogane, "Development of Innovative Variable Valve Event and Lift (VVEL) System," SAE 2007-01-3548, 2007.
  3. H. B. Lee, H. Kwon and K. Min, "Effects of Various VVA Systems on the Engine Fuel Economy and Optimization of a CVVT-VVL SI Engine using 1D Simulation," Int. J. Automotive Technology, Vol.8, No.6, pp.675- 685, 2007.
  4. J. Koo and C. Bae, "Effects of Variable Valve Timing Operation Modes on Engine Performance," Transactions of KSAE, Vol.9, No.6, pp.24-29, 2001.
  5. H. Temekes and J. L. Lumley, A First Course in Turbulence, The MIT Press, pp.50-73, 1972.
  6. FLUENT Manual V.6.3, FLUENT Inc., 2006.
  7. G. B. Parvate-Patil, H. Hong and B. Gordon, "An Assessment of Intake and Exhaust Philosophies for Variable Valve Timing," SAE 2003-32-0078, 2003.