Effects of structural optimization design of gasoline particulate filter on soot emission and performance of GDI engine

Optimizing the structure of gasoline particulate filter (GPF) can effectively improve its equilibrium regeneration performance, thereby reducing the soot emission of the gasoline direct injection (GDI) engine and improving its working performance. Firstly, the mathematical model of GPF device was established based on fluid mechanics and Darcy theory. Then, Fluent software was used to explore the influence of filter structure on its equilibrium state, and the pore density, length, wall thickness and permeability of GPF were optimized by range optimization theory. Finally, the GDI system output performance changes after optimizing the filter structure, including brake-specific fuel consumption (BSFC) and power, were studied by GT-Power software. Results show that: (1) the pore density has a great influence on the pressure drop during the regeneration process of GPF, and the length has a great influence on the average temperature and temperature unevenness coefficient; (2) when the pore density is 200cpsi, the wall thickness is 0.15 mm, the length is 150 mm, and the permeability is 1.5e(-13)m(2), GPF has the best regeneration performance, the pressure drop is reduced by 22.5%, the average temperature is increased by 2.9%, and the R-TIC is reduced by 26.7%. (3) After optimizing the filter structure, the BSFC is reduced by 2.0%, and the power is increased by 6.5%. Therefore, properly reducing the pore density and length of the filter body can effectively improve the regeneration performance of GPF and reduce the pollutant emission of GDI engine.