A One-Dimensional Computational Model for Studying the Filtration and Regeneration Characteristics of a Catalyzed Wall-Flow Diesel Particulate Filter

Abstract

A one-dimensional, two-layer computational model was developed to predict the behavior of a clean and particulate-loaded catalyzed wall-flow diesel particulate filter (CPF). The model included the mechanisms of particle deposition inside the CPF porous wall and on the CPF wall surface, the exhaust flow field and temperature field inside the CPF, as well as the particulate catalytic oxidation mechanisms accounting for the catalyst-assisted particulate oxidation by the catalytic coating in addition to the conventional particulate thermal oxidation. The paper also develops the methodology for calibrating and validating the model with experimental data.

Distribution characteristics of exhaust gases and soot particles in a wall-flow ceramics filter

“…clean channel). The porous wall thickness is very small compared to the length of micro channel, and the radial average gas velocity in the porous wall is small compared to the axial average gas velocity in the channel (Huynh et al, 2003). In addition, the influence of the monolith on the flow in the inlet header region and the velocity distribution entering into the filter is mainly determined by the total pressure drop over the monolith.…”

Nanoparticle motion trajectories and deposition in an inlet channel of wall-flow diesel particulate filter

“…Then, the particle may or may not rebound depending on two factors, which are the physical property of particles and the wall normal velocity (Liu, 2007). The particles from exhaust gas consist of not only the soot, but also the soluble organic fraction (SOF) (Huynh et al, 2003). Hence, there is a high probability of plastic impact between the particle and the porous wall.…”

“…More significantly, none of these studies has considered the effect of Brownian motion. In fact, since the sizes of particles from diesel exhaust gas are in the range of 10-1000 nm (Huynh, Johnson, & Yang, 2003;Konstandopoulos & John, 1989;Li, Huang, & Wang, 2007), the influence of Brownian motion cannot be neglected for nano-particles (Fan & Ahmadi, 2000;Kim & Zydney, 2004;Shams & Ahmadi, 2000;Song & Elimelech, 1995).…”

Modeling of the Regeneration Processes in Diesel Particulate Filters

“…Pressure drop along the channel of the diesel particulate trap is expressed as in [36]: The values of permeability, K andK soot are taken from Versaevel et al [37] and Huynh et al [31], respectively:K = 3.3·10 -13 ,…”