CFD Modeling of a Turbo-Charged Common-Rail Diesel Engine

In this study, a single cylinder diesel engine model is built via the ANSYS FLUENT CFD solver to simulate the phenomenon during each stroke. The initial conditions and boundary conditions are set based on experimental data obtained from a turbo-charged common-rail diesel engine developed by Mitsubishi. The variables that can be observed from the CFD model include cylinder pressure, gas velocity, cylinder temperature, fuel particle tracks, and mass fraction of cylinder gas components. The simulation results display the effects of the fuel injection timings on the combustion heat release process, cylinder pressure and cylinder temperature at different engine operation conditions. The pure diesel (C₁₀H₂₂) is adopted in this simulation study. In the FLUENT setup, k - epsilon is used in the viscous model, and the autoignition model is used to simulate the spontaneous combustion. The flow field obtained from simulation results such as the tumbling motion can be used to explain the macroscopic phenomena observed from experiment results. This research also discusses the effect of fuel injection timing on the cylinder pressure. Results show that as the fuel injection timing advances, the combustion phasing advances, resulting in higher peak cylinder pressure and peak cylinder temperature.