Simulation of soot particle deposition inside porous walls based on lattice Boltzmann method for diesel particulate filter

Abstract The bridge structure inside porous wall is an important feature in diesel particulate filter (DPF) functionality. In this work, the formation process of bridge structure is simulated for the first time by domain decomposition-based lattice Boltzmann-cell automation probabilistic model (DDLB-CA model). The main goals of this work are modeling the formation process of the bridge structure to obtain detailed information and studying the effects of boundary conditions on the bridge structure formation process. The results show that particle clusters first appear in the narrow channels of the porous wall. The bridge structure develops on both sides of the narrow channel based on the deposited particle clusters. After the formation of the bridge structure, the number of soot particles captured by bridge structure increases significantly. These results indicated that the interception, inertia, and diffusion mechanisms play an important role in the early stage of particle filtration, but with the formation of the bridge structure, the bridge structure capture mechanism gradually dominates the capture of particles. The smaller the flow velocity, the earlier the bridge structure is formed. At the same flow velocity, for medium particles, the formation of the bridge structure is the fastest. These results all indicate the importance of the bridge structure capture mechanism in DPF filtration.