Effects of Porosity, Wall Thickness, and Length on the Filtration Efficiency of Gasoline Particulate Filters

The objective of this study was to understand the Gasoline Particulate Filter (GPF) filtration process and examine the effects of GPF parameters, such as wall thickness, porosity, Mean Pore Size (MPS), and length on the Filtration Efficiency (FE). It investigated the implications of installing a GPF on a Gasoline Direct Injection (GDI) engine. Four filters were tested, first on a bench setup with a soot generator as the source for the particle emissions and then on a GDI engine with a dynamometer where the overall emissions and filtration efficiencies were investigated. Soot concentrations, Particle Number (PN) emissions, and gaseous emissions were also measured. Particle morphology and soot deposition were analyzed using a Transmission Electron Microscope (TEM) and a Scanning Electron Microscope (SEM). Results showed an increasing FE as soot deposition increased and a greater effect of porosity and MPS on FE than that of wall thickness or filter size. GPF effects on PN, particle diameter, and fuel efficiency were also discussed.