Soot profile growth in DPF low- and high-loading

Wide activity on Diesel vehicles control devices focuses on experimental, theoretical and numerical aspects of particulate loading and regeneration processes. Wall flow filter models are currently based on CFD models in which a quasi-steady state one-dimensional treatment of the channels is assumed due to the DPF design and to typical engine operating conditions. This assumption is quite realistic for low soot loading operation. However, under high particulate loading, the effect of non-uniform layer of trapped particles in the filter channel has to be accounted for by means of a multidimensional model, since an interaction between the particle profile and the fluid dynamics is expected. This paper presents the results of 3D numerical predictions in which the effects of soot layer growth on flow field are investigated. A parametrization of the collected particles profile is provided, starting from the macroscopic features of the engine-DPF system.