Simulation of deep-bed filtration of a gasoline particulate filter with inhomogeneous wall structure under different particle size distributions

Abstract

In order to describe the microstructure of the porous wall of a gasoline particulate filter (GPF), a pore size distribution based on a probability density function (PDF) and a non-uniform porosity distribution are introduced. The dynamic process of deep-bed filtration in GPF with inhomogeneous wall structure is studied, considering different particle size distributions (PSDs). The results show that most of the particles are captured in the top region of the porous wall, in which the porosity and permeability reduce more obviously during dynamic filtration, and the bottom of the porous wall contributes little to the overall filtration. As time increases, the filtration efficiency of the porous wall for each particle size increases, and the most penetrating particle’s diameter becomes smaller gradually. The dynamic evolution of characteristic parameters of the porous wall, the most efficient filtration region, the pressure drop and the duration of deep-bed filtration are strongly influenced by PSD. This research illustrates the necessity to consider difference of PSDs when working on the filtration process of GPFs.

A study of the early life of gasoline particulate filters: Reactive and dissipative acoustic effects

“…In order to identify the contributions of reactive and dissipative effects, one may consider that any reflection from the device is substantially determined by reactive effects, and therefore these can be characterized by the reflected power ratio W r =W i . From equations ( 6) and (7), one obtains that the reflected power ratio is…”

“…The current trend to tighten emission regulations [1][2][3] is constantly pushing research and development efforts into improving engine performance and enhancing after-treatment systems (ATS) [4][5][6][7] for emissions abatement. To comply with those regulations, the exhaust line of vehicles using internal combustion engines has been gradually complicated by the presence of ATS.…”

“…The reduced storage capacity of GPFs is not as problematic as it could seem, as gasoline particulate emissions are about 10-30 times smaller, and the frequent regeneration makes it difficult to form and maintain a cake layer on the substrate wall. 33 There are some studies in the literature on the early service life of GPFs, 7,33,34 whose results suggest that at this stage, filtration performance is strongly affected by mass deposition and depends on the microstructure of the substrate: due to their reduced size, GDI particles are capable of entering the porous walls, modifying the overall substrate structure and therefore the filtration performance.…”

“…There are some studies in the literature on the early service life of GPFs, 7,33,34 whose results suggest that at this stage, filtration performance is strongly affected by mass deposition and depends on the microstructure of the substrate: due to their reduced size, GDI particles are capable of entering the porous walls, modifying the overall substrate structure and therefore the filtration performance.…”

Numerical Model of Filtration Efficiency Based on Fractal Characteristics of Particulate Matter and Particle Filter

“…Li Zhijun et al introduced PDF-based pore size distribution and non-uniform pore distribution to describe the microstructure of the porous wall of the gasoline particle filter. They considered the dynamic GPF deep bed filtration process with heterogeneous wall structures with different particle size distributions [16].…”