In recent years, lean-burn gasoline Spark-Ignition (SI) engines have been a major subject of investigations. With this solution, in fact, it is possible to simultaneously reduce NOx raw emissions and fuel consumption due to decreased heat losses, higher thermodynamic efficiency, and enhanced knock resistance. However, the real applicability of this technique is strongly limited by the increase in cyclic variation and the occurrence of misfire, which are typical for the combustion of homogeneous lean air/fuel mixtures. The employment of a Pre-Chamber (PC), in which the combustion begins before proceeding in the main combustion chamber, has already shown the capability of significantly extending the lean-burn limit. In this work, the potential of an ultralean PC SI engine for a decisive improvement of the thermal efficiency is presented by means of numerical and experimental analyses. The SI engine is experimentally investigated with and without the employment of the PC with the aim to analyze the real gain of this innovative combustion system. For both configurations, the engine is tested at various speeds, loads, and air-fuel ratios. A commercial gasoline fuel is directly injected into the Main Chamber (MC), while the PC is fed in a passive or active mode. Compressed Natural Gas (CNG) or Hydrogen (H2) is used in the actual case. A 1D model of the engine under study is implemented in a commercial modeling framework and is integrated with “in-house developed” sub-models for the simulation of the combustion and turbulence phenomena occurring in this unconventional engine. The numerical approach proves to reproduce the experimental data with good accuracy, without requiring any case-dependent tuning of the model constants. Both the numerical and experimental results show an improvement of the indicated thermal efficiency of the active PC, compared to the conventional ignition device, especially at high loads and low speeds. The injection of H2 into the PC leads to a significant benefit only with very lean mixtures. With the passive fueling of the PC, the lean-burn limit is less extended, with the consequent lower improvement potential for thermal efficiency.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    1D Numerical and Experimental Investigations of an Ultralean Pre-Chamber Engine


    Additional title:

    Sae Int. J. Engines


    Contributors:

    Published in:

    Publication date :

    2019-11-19


    Size :

    16 pages




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English






    Investigations on Pre-chamber Ignition Device Using Experimental and Numerical Approaches

    Laget, O. / Chevillard, S. / Pilla, G. et al. | British Library Conference Proceedings | 2019


    Investigations on Pre-chamber Ignition Device Using Experimental and Numerical Approaches

    Pilla, G. / Laget, O. / Chevillard, S. et al. | SAE Technical Papers | 2019