Abstract View
Dual-Geometry Pore-Size-Resolved Wall-Flow Filter Deep-bed Loading Model
WEIQI CHEN, Qisheng Ou, Xin Liu, Matti Maricq, David Kittelson, David Y. H. Pui, University of Minnesota
Abstract Number: 617
Working Group: Control and Mitigation Technology
Abstract
Gasoline particulate filter (GPF) is an effective wall-flow technique for gasoline-engine particulate matter (PM) emission control mainly via deep-bed filtration of ceramic walls within the honeycomb cell channels. An analytical filter model is desired for understanding efficiency and pressure drop condition throughout the usage as it is tied to emission regulation and engine performance. Most existing models either oversimplify the filter geometry or do not extend to the soot loading regime such that filter microstructure is modified by particle deposition, leading to altered filter performance. A new advanced loading model is developed based on the classic cell model in this study, which can model the filter wall structure and particle dendritic deposition as two co-existing geometries based on their natural morphologies. On top of it, the pore size distribution of the filter is taken into account throughout the loading process, so the evolution of pore-size-resolved aerosol flow, filtration efficiency, mass loading, particle packing density, and effective fibrous dendritic size can be simulated. In addition, the pore-clogging condition can be estimated without the use of empirical or adjustable parameters. The model validation using filter loading experimental data shows that the model can provide fairly good predictions on both filter efficiency and pressure drop at the same time during deep-bed loading for different wall-flow filters under different operation conditions. By using the model, the change in morphology of particle dendritic structure in different pores for deep filtration was investigated. The impacts of pore size distribution and pore-clogging condition were studied, which suggest that improving the pore size uniformity can improve filter performance in both clean and loading filtration regime.