Modeling and Analysis on the Particle Trapping and Pressure Drop Performance of Wall-Flow Diesel Particulate Filter With Different Structure Parameters

Abstract The wall-flow diesel particulate filter (DPF) is the most effective technology for reducing engine particulate matter emissions. This study developed a model integrating trapping and pressure drop to analyze the impact of structural parameters on DPF performance. The results indicate that the comprehensive trapping coefficient decreases with the increasing particulate size and increases with the rising exhaust temperature, but decreases with the increasing exhaust flowrate. This coefficient increases with larger filter volume, higher pore density, and smaller wall thickness or aspect ratio, while an increase in porosity also enhances trapping performance. Specifically, increasing the pore density from 100 cpsi to 200 cpsi and 300 cpsi improved the trapping efficiency by 20.2% and 10.4%, respectively. In terms of pressure drop, in both the deep-bed trapping stage and the cake trapping stage, the pressure drop increases linearly with the increase in exhaust flowrate. Larger DPF volume, higher pore density, increased aspect ratio, and thinner wall thickness all contribute to reducing pressure drop. Increasing the volume from 14.18 L to 15.97 L reduces the average pressure drop in the deep-bed trapping stage and the cake trapping stage by 11.2% and 15.3%, respectively; while increasing the pore density from 100 cpsi to 200 cpsi reduces it by 25.3% and 25.0% in these two stages, respectively. These findings provide a crucial foundation for designing efficient and low-resistance wall-flow DPFs.