DoE Based CFD Analysis of Diesel Combustion and Pollutant Formation

Computational Fluid Dynamics is applied to the analysis and optimization of combustion and pollutant formation in a high-speed DI diesel engine. The work focuses on the analysis of the impact of in-cylinder swirl, start-of-injection, injection pressure and residual gas content on the engine performance and emissions characteristics for a part load operating point. The 3D-CFD calculations are carried out with the commercial CFD code AVL FIRE. The methodology adopted in the present study follows a Design of Experiment (DoE) approach in order to minimize the number of calculation runs for analysis of the impact of the relevant combustion system parameters on the engine combustion and emission performance. Validation of the adopted methodology with respect to both the accuracy of the adopted combustion and pollutant formation models and the DoE-based calculation approach is achieved by comparison of the computational results with engine measurement data.