TY - JOUR
TI - Development of a two zone turbulence model and its application to the cycle-simulation
AU - Sjerić Momir
AU - Kozarac Darko
AU - Tomić Rudolf
JN - Thermal Science
PY - 2014
VL - 18
IS - 1
SP - 1
EP - 16
PT - Article
AB - The development of a two zone k-ε turbulence model for the cycle-simulation  software is presented. The in-cylinder turbulent flow field of internal  combustion engines plays the most important role in the combustion process.  Turbulence has a strong influence on the combustion process because the  convective deformation of the flame front as well as the additional transfer  of the momentum, heat and mass can occur. The development and use of  numerical simulation models are prompted by the high experimental costs, lack  of measurement equipment and increase in computer power. In the  cycle-simulation codes, multi zone models are often used for rapid and robust  evaluation of key engine parameters. The extension of the single zone  turbulence model to the two zone model is presented and described. Turbulence  analysis was focused only on the high pressure cycle according to the  assumption of the homogeneous and isotropic turbulent flow field. Specific  modifications of differential equation derivatives were made in both cases  (single and two zone). Validation was performed on two engine geometries for  different engine speeds and loads. Results of the cyclesimulation model for  the turbulent kinetic energy and the combustion progress variable are  compared with the results of 3D-CFD simulations. Very good agreement between  the turbulent kinetic energy during the high pressure cycle and the  combustion progress variable was obtained. The two zone k-ε turbulence model  showed a further progress in terms of prediction of the combustion process by  using only the turbulent quantities of the unburned zone.