Three-Dimensional Simulation of a Single-Channel Three-Way Catalytic Convertor

A single channel, three-dimensional model is developed to simulate the behavior of a three-way catalytic converter. The flow regime is assumed to be steady and laminar, and the channel walls are considered as isothermal. A global heterogeneous reaction mechanism with 16 reactions and 11 species is used in this investigation to enhance the accuracy of the results. The chemical reactions are assumed to occur only on the reactor walls. The developed model is validated against available experimental and one-dimensional numerical data for stoichiometric operating conditions. Better agreements with experimental data are obtained compared with the previous 1D model. The effect of the feed temperature on conversion efficiency of the main pollutant components is also studied. The light-off temperature is found to be 530 K for CO, NO and UHC and 425 K for H2 conversion. The model is also applied to predict the effect of the monolith cell density (channel cross section area) on the conversion efficiency at a baseline temperature. The results show that for a side length of less than 0.8 mm all of the pollutants can be removed.

کلیدواژه ها:

catalytic converter ، automotive pollutants ، surface reactions ، CFD simulation ، optimization