1D and 3D CFD Simulation of Exhaust-Gas Aftertreatment Devices: Parameter Optimization via Genetic Algorithm

Future limits on emissions for both gasoline and Diesel engines require adequate and advanced systems for the aftertreatment of the exhaust gas. Computer models as a complementary tool to experimental investigations are indispensable to design reliable after-treatment devices such as catalytic converters and Diesel particulate filters. Therefore, the objective of this contribution is to present an integrated 1D to 3D simulation workflow of catalytic converters (Three-Way-Catalyst, Diesel Oxidation Catalyst, Selective Catalytic Reduction Catalyst, ...) and Diesel particulate filters. The parameters or sets of parameters are obtained by a fast and efficient 1D-approach of BOOST. They are readily transferable to the 3D simulation code FIRE to investigate detailed aspects such as spatial distribution of temperatures or heat losses. Thus, identical models predicting flow, energy and conversion of species of the exhaust gas were employed to both the 1D gas exchange/cycle and the 3D CFD simulation code. This approach allows to carry out a basic analysis and to define first layouts for the exhaust system. Characteristic parameters of this first design stage are used for the multi-dimensional simulation to evaluate the overall performance including fine tuning of aftertreatment systems.