Impact Investigation of Structural Parameters and Inlet Exhaust Gas Boundary Conditions on Particles Trapping Efficiency of Carrier Wall in GPF Based on a Non-Homogeneous Dynamic Extended Capture Model

To accurately predict the performance of GPF trapping, this study proposes a non-homogeneous dynamic extended capture model for a gasoline particulate filter (GPF). The model consists of a non-homogeneous filter wall sub-model, a filter wall temperature sub-model, a particle size distribution sub-model, and a capture unit sub-model. The distribution of pore size, inlet particles, and growth of the trapping unit were considered in the model to improve its accuracy. A bench test was conducted to validate the model on a GS61 1.5 L direct injection gasoline engine, combined with three particle filters of different structural parameters. Based on the proposed model, the influence of structural parameters and inlet tail gas boundary conditions, as well as the inlet particle’s properties, on the filtration efficiency of the carrier wall was investigated. The results show that the length, cell density, and wall thickness of the carrier wall have a significant effect on the filtration efficiency of the filter wall, while the porosity, mean, and variance in pore size distribution of the carrier wall have a greater effect on the initial filtration efficiency. As for the inlet tail gas boundary conditions and the inlet particle’s properties, the inlet tail gas flow rate and the amount of particles have a significant impact on the filtration efficiency of the GPF. Specifically, GPFs with shorter length, smaller cell density, and thicker walls, while appropriately reducing the porosity and the mean and variance of pore size of the carrier wall, can effectively improve the filtration efficiency. The larger the number of particles, the larger the average particle diameter, and the more dispersed the particle size distribution, the higher the filtration efficiency of the GPF.