The paper studied the burn rate of fuels in the CFR engine at standard knock intensity. Burn duration was found to increase with compression ratio, and knocking pressure traces exhibited a distinct change in slope, thought to be the onset of knock. A criterion was developed to identify this knock-point. The knock-point was related to the mass fraction bunt and it was found that the mass fraction burnt at the knock-point decreases as the compression ratio decreases, to as little as 30%. It is proposed that the nature of knock in the CFR engine is unique in that a large fraction of the trapped mass participates in the autoignition. The paper also presented a functional descriptor for the mass fraction burnt and illustrated the suitability thereof through the application in an engine model.


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    Title :

    Standard Knock Intensity Revisited: Atypical Burn Rate Characteristics identified in the CFR Octane Rating Engine


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    2004 SAE Fuels & Lubricants Meeting & Exhibition ; 2004



    Publication date :

    2004-06-08




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English


    Keywords :



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