Factors influencing resuspended PM2.5 from the tires of two-wheeled electric vehicles

The dust resuspended by tire motion is a key cause of particulate matter pollution. The resuspension of PM2.5 by tires of a two-wheeled electric vehicle was numerically simulated using Fluent under different conditions including different tire speed, wind speed, wind direction. The average pressure on the windward and leeward sides of the tires was 10.40 and 8.79 Pa, respectively, and the average pressure on the outside and inside sides was 9.59 and 2.65 Pa, respectively, when the wheel was moving forward. The average airflow speed on the windward and leeward sides of the tire was 5.25 and 5.56 m/s. The PM2.5 concentration distribution was more centralized at the start of tire motion, and the average PM2.5 concentration in the wake flow was 1.74 × 10−7 kg/m3 at t = 1 s. With tire motion, PM2.5 distribution gradually spread, and the average PM2.5 concentration of the wake flow was 6.18 × 10−7 kg/m3 at t = 5 s. The PM2.5 resuspended by the tire decreased with z direction. The average PM2.5 concentrations at the tire center cross section at wind grade 0 for downwind and upwind were 2.70 × 10−8 and 2.30 × 10−8 kg/m3, respectively. The experimental and simulation results had the highest correlation at a tire speed of 15 km/h and the lowest correlation at a tire speed of 25 km/h.