Controlled auto-ignition, also known as homogeneous charge compression ignition, has been the subject of extensive research because of their ability to provide simultaneous reductions in fuel consumption and NOx emissions from a gasoline engine. However, due to its limited operation range, switching between controlled auto-ignition and spark ignition combustion is needed to cover the complete operating range of a gasoline engine for passenger car applications. Previous research has shown that the spark ignition-controlled auto-ignition hybrid combustion (SCHC) has the potential to control the ignition timing and heat release process during the mode transition operations. However, it was found that the SCHC is often characterized with large cycle-to-cycle variations. The cyclic variations in the in-cylinder pressure are particularly noticeable in terms of both their peak values and timings while the coefficient of variation in the indicated mean effective pressure is much less. In this work, the cyclic variations in SCHC operations were analyzed by means of in-cylinder pressure and heat release analysis in a single-cylinder gasoline engine equipped with Variable Valve Actuation (VVA) systems. First, characteristics of the in-cylinder pressure traces during the spark ignition-controlled auto-ignition hybrid combustion operation are presented and their heat release processes analyzed. In order to clarify the contribution to heat release and cyclic variation in SCHC, a new method is introduced to identify the occurrence of auto-ignition combustion and its subsequent heat release process. Based on the new method developed, the characteristics of cyclic variations in the maximum rate of pressure rise and different stages of heat release process have been analyzed and discussed.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Analysis of cyclic variations during mode switching between spark ignition and controlled auto-ignition combustion operations




    Publication date :

    2015




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English



    Classification :

    BKL:    52.35 Kolbenkraftmaschinen / 52.35




    The Effects of External EGR During Spark Ignition/Controlled Auto Ignition Combustion Transitions (20065410)

    Caims, A. / Blaxill, H. / Society of Automotive Engineers of Japan | British Library Conference Proceedings | 2006



    Controlling cyclic combustion variations in lean-fueled spark-ignition engines

    Davis,L.I. / Feldkamp,L.A. / Hoard,J.W. et al. | Automotive engineering | 2001


    Controlling Cyclic Combustion Variations in Lean-Fueled Spark-Ignition Engines

    Daw, C. S. / Yuan, F. / Connolly, F. T. et al. | SAE Technical Papers | 2001