An experimentally derived map of the engine volumetric efficiency is usually employed to control the A/F ratio in a SI-ICE. In the case of a variable valve timing (VVT) engine, a different efficiency map must be considered at each camshaft position, as a consequence of the influence on the air flow exerted by the actual position of the intake/exhaust camshaft. In this paper, an attempt is reported to theoretically derive a correlation of the volumetric efficiency as a function of engine speed, manifold absolute pressure, and camshaft position. The correlation is not based on experimental data but on the results of a one-dimensional simulation model (1Dime code) developed at DIME. An extensive validation of the 1D model is preliminary reported in the first part of the paper. The procedure is developed with reference to a four-cylinder, SI engine, equipped with a phased intake and exhaust VVT device. The latter includes a “slider” which deactivates a tumble-flow inducing port for burning speed enhancement at part-load. The derived correlation also accounts for the variations of ambient conditions and can be directly included within the classical strategies for A/F Ratio control, programmed inside the ECU. The whole methodology allows to greatly reduce the experimental efforts required to fully characterize the VVT engine and to develop its control logic.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    The Employment of a 1D Simulation Model for A/F Ratio Control in a VVT Engine


    Additional title:

    Sae Technical Papers


    Contributors:
    Torella, E. (author) / Bozza, F. (author)

    Conference:

    SAE 2003 World Congress & Exhibition ; 2003



    Publication date :

    2003-03-03




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English





    The employment of a 1D simulation model for A/F ratio control in a VVT engine

    Bozza,F. / Torella,E. / Univ.di Napoli,IT et al. | Automotive engineering | 2003



    COMPRESSION RATIO CONTROL DEVICE AND ENGINE

    MASUDA YUTAKA / UMEMOTO YOSHIYUKI / TAKIMOTO TAKAHIRO et al. | European Patent Office | 2020

    Free access

    Compression ratio control device and engine

    MASUDA YUTAKA / UMEMOTO YOSHIYUKI / TAKIMOTO TAKAHIRO et al. | European Patent Office | 2021

    Free access