Browse Publications Technical Papers 2005-01-2133

Characteristics of HCCI Engine Operating in the Negative-Valve-Overlap Mode 2005-01-2133

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.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.