Spark-assisted compression ignition (SACI) offers more practical combustion phasing control and a lower pressure rise rate than homogeneous charge compression ignition (HCCI) combustion and improved thermal efficiency and lower NOx emissions than spark ignition (SI) combustion. Any practical passenger car engine, including one that uses SACI in part of its operating range, must be robust to changes in ambient conditions. This study investigates the effects of ambient temperature and humidity on stoichiometric SACI combustion and emissions. It is shown that at the medium speed and load SACI test point selected for this study, increasing ambient air temperature from 20 °C to 41 °C advances combustion phasing, increases maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition (and a smaller fraction by flame propagation), and increases NOx. Increasing ambient humidity from 32% to 60% retards combustion phasing, reduces maximum pressure rise rate, increases coefficient of variation (COV) of indicated mean effective pressure (IMEP), reduces NOx, and increases brake-specific fuel consumption (BSFC). These results show that successful implementation of SACI combustion in real-world driving requires a control strategy that compensates for changes in ambient temperature and humidity.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Effect of Ambient Temperature and Humidity on Combustion and Emissions of a Spark-Assisted Compression Ignition Engine




    Publication date :

    2017




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English



    Classification :

    BKL:    52.30 / 52.52 / 52.52 Thermische Energieerzeugung, Wärmetechnik / 52.30 Strömungskraftmaschinen, Turbomaschinen





    Development of an Innovative Combustion Process: Spark-Assisted Compression Ignition

    Kaechele, Andreas / Poetsch, Christian / Wichelhaus, Donatus et al. | SAE Technical Papers | 2017


    Development of an innovative combustion process: Spark-assisted compression ignition

    Chiodi, M. / Kächele, Andreas / Bargende, Michael et al. | Springer Verlag | 2018


    Temperature Gradients in Spark Ignition Engine Combustion Chambers

    James,E.H. / Loughborough Univ.of Technol.,Mech.Engng.Dep.,GB | Automotive engineering | 1980