A single-cylinder engine with a transparent piston crown was tested with three intake geometries which produced different levels of swirl, and with two spark locations. A heat-release analysis was performed on the accumulated pressure-time data. Using this data base, relationships of maximum cycle pressure and its location in the cycle to the placement of the burn in the cycle are developed for different burning rates as a means of diagnosing sources of combustion variability.Among the significant observations were that combustion variability for operation away from the lean limit or incipient misfire is not strongly dependent on flow conditions at the spark plug and early flame behavior, but more dependent on the cyclic repeatability of the overall cylinder flow pattern. In the region of incipient misfire the early flame process becomes a significant source for variability. The onset of significant variability in IMEP corresponds to a condition where a collection of cycles shows the production of an increasing number of abnormally late burns as the spark is advanced. Additional spark advance results in the occurrence of misfire at approximately the frequency of the late-burn occurrence.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Modes and Measures of Cyclic Combustion Variability


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE International Congress and Exposition ; 1983



    Publication date :

    1983-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Modes and measures of cyclic combustion variability

    Matekunas,F.A. / General Motors Res.Lab.,US | Automotive engineering | 1983



    Analysis of cyclic variability in combustion in internal combustion engines using wavelets

    Tily,R. / Brace,C.J. / Univ.of Bath,School of Mech.Engng.,GB | Automotive engineering | 2011



    Improving efficiency of the premixed combustion by reducing cyclic variability

    Sotiropoulou,E. / Zhu,S. / Tozzi,L. et al. | Automotive engineering | 2016