Gasoline Particulate Filter Modeling with Catalytic Washcoat and Ash Accumulation and Transient Soot Distribution Prediction

The upcoming EURO 7, China 7, and EPA Tier 4 regulations are expected to tighten the tailpipe particulate emissions extensively. High performance Gasoline Particulate Filters (GPFs) with high filtration efficiency and low pressure drop would be mandated for gasoline engines to meet these stringent regulations. Due to packaging constraints, GPFs are often coated with three-way catalyst (TWC) materials to achieve four-way functionality. Ash accumulation in GPFs also has a significant impact on the performance of GPFs. The conventional 0D/1D GPF models can be effective for basic pressure drop and filtration efficiency prediction, but have their limitations. Previous studies have proven that 3D CFD model can provide more comprehensive data on soot distribution in and on top of GPF wall substrate. This paper continues utilizing 3D CFD to investigate the effects of washcoating and ash accumulation on the filtration efficiency and pressure drop of GPFs during the soot loading process. Simulation results show decent match with experimental data for both bare and ash-loaded washcoated GPFs. The 3D CFD model also provides detailed information on soot penetration in the GPF wall substrate and soot cake characteristics on the wall. These information can be crucial for GPF wall substrate design and washcoating strategy design.