Lattice Boltzmann simulation on continuously regenerating diesel filter

Abstract

To reduce particulate matter (PM) including soot in diesel exhaust gas, a diesel particulate filter (DPF) has been developed. Since it is difficult to observe the phenomena in a DPF experimentally, we have conducted a lattice Boltzmann simulation. In this study, we simulated the flow in a metallic filter. An X-ray computed tomography (CT) technique was applied to obtain its inner structure. The processes of soot deposition and oxidation were included for a continuously regenerating diesel filter. By comparing experimental data, a parameter of soot deposition probability in the numerical model was determined.

Effect of Pore Structure on Soot Deposition in Diesel Particulate Filter

“…Then, we do not have to consider the real geometry of the diesel soot. Uniquely, the soot deposition probability on the filter substrate, P D , has been proposed previously [9,11]. Our collaborators, including an automobile company and a Japanese national institute, estimated the value of the soot deposition probability, and it was 0.002 in the case of the cordierite filter [29].…”

“…One of our unique procedures is that we use CT data of inner structure of DPF to realize the real fluid flow in the filter. In our last several papers [7][8][9][10][11], we have simulated the soot trap and regeneration of the filter. Due to the computational costs, it must be impractical to consider the real geometry of the diesel soot, because it is carbonaceous agglomerates with several-micrometer primary soot [3,27,28].…”

“…Many research papers have been published, especially for simulations in porous media [14][15][16][17][18]. In our previous studies, we have made great progress for developing the numerical approach of the soot particle-laden diesel exhaust gas by LBM [8][9][10][11]. So far, we could discuss the particle filtration together with pressure rise, which appears in the real usage of the diesel filter.…”

“…However, in conventional computational code, it would still be difficult to take the filtration process into consideration, because we must set the complex boundary conditions at the very concave and convex filter substrate. Quite recently, a lattice Boltzmann method (LBM) has been widely used for alternative fluid simulation [7][8][9][10][11][12][13]. Many research papers have been published, especially for simulations in porous media [14][15][16][17][18].…”

“…So far, we could discuss the particle filtration together with pressure rise, which appears in the real usage of the diesel filter. Moreover, mass and heat transport was modelled for the filter regeneration process, by which it could be possible to discuss the soot oxidation in the catalyzed filter [7,10,11,19].…”