Planar instantaneous fuel concentration measurements were made by laser-induced fluorescence of 3-pentanone in the spark gap just prior to ignition in a direct-injection spark-ignition engine operating at a light load, highly stratified condition. The distribution of the average equivalence ratio in a circle of 1.9 mm diameter centered on the spark plug showed that a large fraction of the cycles had an equivalence ratio below the lean limit, yet acceptable combustion was achieved in those cycles. Further, weak correlation was found between the local average equivalence ratio near the spark plug and the time required to achieved a 100 kPa pressure rise above the motoring pressure, as well as other parameters which characterize the early stages of combustion. The cause for this behavior is assessed to be mixture motion during the spark discharge which continually convects fresh mixture through the spark gap during breakdown. Such high mixture motion is inherent in direct injection systems because of the requirements placed on mixing for full load operation, and the influence of the spray on the flowfield for light load conditions where the injection and ignition event may overlap. The implication is that good ignition of stratified charges is not necessarily a main difficulty, particularly if engine development includes detailed in-cylinder measurements.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Mixture Preparation Effects on Ignition and Combustion in a Direct-Injection Spark-Ignition Engine


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    1996 SAE International Fall Fuels and Lubricants Meeting and Exhibition ; 1996



    Publication date :

    1996-10-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Mixture preparation for direct-injection spark ignition engines

    Ohsuga,M.Shiraishi,T. / Nogi,T. / Nakayama,Y. et al. | Automotive engineering | 1997



    Combustion Characteristics of a Direct-Injection Spark-Ignition Methanol Engine

    Li, B. / Gong, Y. / Liu, S. | British Library Online Contents | 2008


    Analysis of direct injection spark ignition combustion in hydrogen lean mixture

    Shudo,T. / Tsuga,K. / Nakajima,Y. et al. | Automotive engineering | 2000


    Mixture Formation Analysis in a Direct Injection Spark Ignition (DISI) Engine

    Pinheiro Martins, Fernanda / De Souza, Francisco José | SAE Technical Papers | 2010