Gasoline Particulate Filter Substrate Heterogeneity Effects on Its Performance

Continuously tightening Particulate Matter (PM) and Particulate Number (PN) regulations make Gasoline Particulate Filters (GPFs) with high filtration efficiency and low pressure drop highly desirable as Gasoline Direct Injection (GDI) engines increase in market share. Due to packaging constraints, GPFs are often coated with three-way catalyst (TWC) materials to achieve four-way functionality. Therefore, it is critical to investigate the effects of various washcoating strategies on GPF performance. A three-dimensional (3D) Computational Fluid Dynamics (CFD) model, along with an analytical filtration model was created. A User Defined Function (UDF) was implemented to define the heterogeneous properties of the GPF wall due to washcoating or ash membrane application. The model demonstrated the ability to predict transient filtration efficiency and pressure drop of uncoated and washcoated GPFs. Simulation results showed the evenly coated GPF yielded the best performance compared to other washcoating profiles. The model-predicted results indicated that the sample GPF with a 2.6 g/L ash loading was able to achieve a balance between high initial filtration efficiency and low pressure drop.