A LES numerical approach for investigating the cycle-to-cycle combustion pressure variability in a direct injection gasoline engine
The Large Eddies Simulation method (LES) has become a powerful computational tool for the application to turbulent flows. It links the classical Reynolds Averaged Navier–Stokes (RANS) approach and Direct Numerical Simulation (DNS). This means that the large eddies are computed explicitly in a time-dependent simulation using the filtered Navier-Stokes equations. LES resolves the large flow scales that depend directly on the geometry where small scales are modelled by the sub-grid-scale models. LES is expected to improve the description of the aerodynamic and combustion processes in Internal Combustion Engines. This paper addresses the topic of developing the combustion model GCM (Gradient Combustion model) for the Large Eddy Simulation (LES) method. Another part of this paper presents numerical investigations of cycle-to-cycle combustion pressure variability with comparison to experimental data. The Gradient Combustion model (GCM) based on the Turbulent Flame Speed Closure Model (TFSCM) is validated against the experimental data for a multi-cycle gasoline direct injection research engine. It is shown that the introduced combustion model is stable and capable of proper representation of the experimental results which is one of the assets of the LES method.
Tematyka artykułu: Modelowanie i optymalizacja procesów w silnikach
Autor: Andrzej TEODORCZYK
Współautor(zy): Piotr JAWORSKI, Peter PRIESCHING, Reinhard TATSCHL