Simulating the Concentration Equations and the Gas-Wall Interface for One-Dimensional Based Diesel Particulate Filter Models

Abstract

This paper enhances an earlier publication by including the concentration equations of motion into the area-conserved one-dimensional based diesel particulate filter model. A brief historical review of the species equations is accomplished to describe this model and the pertinent physics involved. In the species equations through the wall and soot layers, the diffusion constants are modified to account for the close proximity of the porous walls and the particulate matter to the gas flowing through the accompanying layers. In addition, a review of potential options involving the diffusion velocity is accomplished to determine the effect of pressure gradients on this phenomenon. In the previous paper, the model formulation illustrated that a common assumption to make for an enthalpy difference is the use of constant pressure specific heat times a temperature difference. Because of the different heats of formation and sensible enthalpies associated with the chemical species, this assumption reviewed is found to have a related error. Finally, because each channel is treated as an open system, making the common assumption of dilute mixture simplification is reviewed and found to have an associated error.