Browse > Article

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

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)
Publication Information
Transactions of the Korean Society of Automotive Engineers / v.18, no.2, 2010 , pp. 7-13 More about this Journal
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
CFD; Valve lift; Valve timing; Residual gas; Volumetric efficiency; Pumping loss;
Citations & Related Records
연도 인용수 순위
  • Reference
1 H. Temekes and J. L. Lumley, A First Course in Turbulence, The MIT Press, pp.50-73, 1972.
2 FLUENT Manual V.6.3, FLUENT Inc., 2006.
3 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.
4 T. Sugiyama, R. Hiyoshi, S. Takemura and S. Aoyama, "Technology for Improving Engine Performance using Variable Mechanisms," SAE 2007-01-1290, 2007.
5 S. Kiga, Y. Mae, Y. Akasaka and K. Tomogane, "Development of Innovative Variable Valve Event and Lift (VVEL) System," SAE 2007-01-3548, 2007.
6 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.
7 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.