Characteristics of HCCI Engine Operating in the Negative-Valve-Overlap Mode
2005-01-2133
05/11/2005
- Event
- Content
- Characteristics of un-throttled HCCI engine using negative valve overlap were examined under steady state and step-load change operations. The analysis employed a combined heat release analysis of the pressure data and a cycle simulation with a 1D gas exchange model to extract the residual fraction and the compression temperature from the experimental data. The residual gas fraction decreased with increase in engine load; the compression temperature decreased correspondingly. Substantial pumping loss attributed to the heat transfer in the re-compression process and the gas exchange friction was observed. At “optimum” setting of the combustion phasing, the GIMEP was not sensitive to the cycle-to-cycle combustion phasing variation. Large step high-to-low change in load was found to be stable. The reverse, however, had combustion failure in the first cycle due to unfavorable compression temperature and residual gas fraction.
- Pages
- 12
- Citation
- Santoso, H., Matthews, J., and Cheng, W., "Characteristics of HCCI Engine Operating in the Negative-Valve-Overlap Mode," SAE Technical Paper 2005-01-2133, 2005, https://doi.org/10.4271/2005-01-2133.