A fluid dynamic model for unsteady compressible flow in wall-flow diesel particulate filters

The use of particulate filters (DPF) in Diesel engines has become in recent years the standard technology for the control of soot aerosol emissions. Once emissions reduction through the management of filtration and regeneration aspects has reached its maturity, the effect of the system location on engine performance and acoustics are key topics to be addressed. In this paper, a fluid dynamic model for wall-flow monolith filters is described in which non-homentropic one-dimensional unsteady compressible flow is considered. The good agreement with experimental data confirms that the model is able to describe the mechanisms contributing to the pressure drop across the whole filter under steady and impulsive flow conditions. The approach of the flow governing equations provides a reliable evaluation of the contributions to the pressure drop with axial resolution in the description of the flow field properties. In addition, the frequency response predicted by the model confirms its ability to evaluate the dynamic response and acoustic potential of the DPF.