Study on Structure Optimization of Diesel Particulate Filter Based on Flow Field Distribution Characteristics

The flow field distribution characteristic of diesel particulate filter (DPF) is very important to the regeneration. Taking the wall-flow honeycomb ceramic filter as an example, based on the k -ε turbulence, gas-particle flows and porous medium theory models, the velocity and the particulate concentration distribution field have been studied and analyzed during the DPF filtration. The results indicate that the vortex emerges around the small area wall when the flow passed the dilation pipe, but laminar flow inner the filter. And with the axis position increase, the axial velocity is more uniform distributed along the radial direction in all channels of the filter. The flow field uniformity will be good for the DPF pyrogenation regeneration. Particulate concentration distribution is very different in every radial channel along the axial direction. The particulate concentration is greater in the center area channels. It will cause the larger heat burden during the DPF regeneration, and influence the DPF working life. Therefore, it is very necessary to improve the interior DPF flow field distribution, in the paper, it is realized by the optimal design for DPF structure through adjusting the key dimension parameters such as diameter ratio, dilation angle etc.