The paper describes the emulation of the knock measurement equipment on the CFR engine used during octane rating. It was found during engine measurements that the low-pass filtered rate-of-change of the pressure signal from Primary Reference Fuels (PRF) established the definitive metric of standard knock intensity and that non-PRF fuels exhibited similar pressure rise rates at standard knock intensity. The effect of fuel octane number, compression ratio and air-fuel ratio was also clearly distinguishable.Further modelling interpretation revealed that a non-instantaneous, cascading autoignition was a likely origin for the measured pressure development. Thermal inhomogeneities, which were the result of a heat loss gradient in the trapped mass, served to explain the observed behaviour of both RON and MON test conditions and a range of fuels of different octane numbers. A predictive model was ultimately applied to demonstrate that the pressure development and pressure rise rate can be predicted from the physical conditions in the engine, coupled to a fuel ignition delay descriptor.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Insights into the Role of Autoignition during Octane Rating


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    2007 Fuels and Emissions Conference ; 2007



    Publication date :

    2007-01-23




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English


    Keywords :


    Insights into the Role of Autoignition during Octane Rating

    Swarts, A. / Yates, A. / Society of Automotive Engineers | British Library Conference Proceedings | 2007


    Insights into the role of autoignition during octane rating

    Swarts,A. / Yates,A. / Univ.of Cape Town,ZA | Automotive engineering | 2007



    Investigation of the octane rating and autoignition temperature of methanol-gasoline blends

    Nichols,R.J. / Aerospace Corp.,US | Automotive engineering | 1980


    Investigation of Kinetics of Iso-Octane Autoignition

    Chen, Qisheng / Hong, Yanji / Zhao, Wentao et al. | AIAA | 2014