Early direct injection with HCCI like properties is characterized by the presence of an ignition dwell - the interval between end of fuel injection and start of combustion, during which fuel-air mixing occurs. Previous work by Jhavar and Rutland (2005) has focused on investigating different methods to affect fuel-air mixing during the ignition dwell. That study helped to evaluate the relative influence of various mixing control strategies to achieve ignition control. In this study, we attempt to look into the mixture preparation process in more detail. Therefore, turbulence is studied using Large Eddy Simulation (LES) models in place of Reynolds Averaged Navier Stokes (RANS) models. While LES is computationally more expensive than RANS, it depicts the flow structure more accurately. Therefore, it can be applied to engines in order to gain a better representation of local mixing as well as accurately simulate unsteady flow behavior in engines. In this study, various LES models have been added to the KIVA-3V code. Early injection cases have been simulated on a CAT 3401 engine mesh and comparisons made with RANS results. LES results show more detailed flow structure and therefore enable a more accurate study of mixing. Multiple cycle cases have also been simulated and compared to identify cycle to cycle variations. A grid sensitivity study for LES has also been performed. In addition to this, LES has been added to KIVA-CHEMKIN for more accurate flow representation. Currently the DOLFA technique (Haworth et al. 2003) is being added with KIVA-CHEMKIN to speed up kinetics calculations.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Using Large Eddy Simulations to Study Mixing Effects in Early Injection Diesel Engine Combustion


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    SAE 2006 World Congress & Exhibition ; 2006



    Publication date :

    2006-04-03




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Using large eddy simulations to study mixing effects in early injection diesel engine combustion

    Jhavar,R. / Rutland,C.J. / Univ.of Wisconsin-Madison,US | Automotive engineering | 2006


    Effects of mixing on early injection diesel combustion

    Jhavar,R. / Rutland,C.J. / Univ.of Wisconsin-Madison,US | Automotive engineering | 2005


    Effects of Mixing on Early Injection Diesel Combustion

    Rutland, Christopher J. / Jhavar, Rahul | SAE Technical Papers | 2005


    Combustion Modeling of Conventional Diesel-type and HCCI-type Diesel Combustion with Large Eddy Simulations

    Hu, Bing / Rutland, Christopher J. / Shethaji, Tushar A. | SAE Technical Papers | 2008


    Combustion modeling of conventional diesel-type and HCCI-type diesel combustion with Large Eddy Simulations

    Hu,B. / Rutland,C.J. / Shethaji,T.A. et al. | Automotive engineering | 2008