This study investigated the effectiveness of tap water application in reducing nano-sized wear particles at a wheel-rail contact interface and its impact on air quality at different train velocities. Airborne wear particles (AWPs) were simulated using a twin-disk rig at 500, 800, and 1,300 RPM. Mass concentration of nano-sized wear particles was measured using a fast mobility particle sizer (FMPS) at a sampling frequency of 1 Hz. To simulate various vehicle dynamics and contact conditions, the slip rate was incrementally increased from 0 to 3%. During wet conditions, water was applied at a rate of 7 L/min. PM0.1 and PM0.56 under dry and wet conditions were compared to evaluate the method’s effectiveness. The analysis showed that the tap water application method improved the air quality by reducing PM0.56 by at least 74% and PM0.1 by approximately 80%. In conclusion, the water application method can effectively improve air quality by reducing generation of nano-sized wear particles. The train velocity affected the generation of nano-sized wear particles under both conditions.

The effectiveness of applying tap water method to reduce the generation of nano-sized wear particles from wheel-rail contacts in the aspect of air quality was investigated. A twin-disk rig was utilized to simulate the generation of airborne wear particles resulting from wheel-rail contacts. Slip rates ranging from 0 to 3% were continuously generated to simulate various railway vehicle dynamics. Dry and tap water application conditions (7 L/min) were tested. The mass concentration of wear particles with sizes below 560 nm generated during tests was measured using a Fast Mobility Particle Sizer (FMPS). Particles measured in the slip zone (0 to 3%) were categorized into PM0.02, PM0.03, PM0.1, and PM0.56 for analysis. Results indicated a significant decrease in mass concentration of particles with sizes above 30 nm, while those with sizes below 30 nm showed an increase. Particle reduction rate was -217.2% for PM0.02, -58.5% for PM0.03, 84.5% for PM0.1, and 90.3% for PM0.56. It should be noted that a negative reduction rate indicates an increase in the amount of particle generation. This study demonstrates that the application of tap water is effective in improving air quality by reducing the generation of nano-sized wear particles overall.