“In the field of diesel particulate filters, experts built a three-dimensional model based on CFD software to study the effects of soot and ash distribution on DPF airflow movement, and established a one-dimensional thermodynamic whole machine model to explore the influence of DPF carrier size, wall thickness, and inlet/outlet aperture ratio on its noise characteristics in high-altitude environments. The results indicate that the flow velocity of the DPF intake duct first increases and then decreases along the axial direction of the starting end, and decreases along the radial position of the wall from the starting end of the centerline. In high-altitude environments, the influence of carrier diameter on noise is more significant than carrier length; The carrier diameter of 190 mm has a better noise attenuation effect than the diameter of 170 mm, reaching over 3 dB; When the inlet/outlet aperture ratio is 1.1, the noise at the DPF exhaust end is the lowest, and the noise attenuation amplitude increases with the increase of carbon load (0-8 g/L), with a decrease of about 3 dB.”