Investigation of the Dynamic Characteristics of PM<sub>2.5</sub> Dispersion During the Acceleration of Motor Vehicles in Urban Streets Based on Computational Fluid Dynamics and Dynamic Mode Decomposition
Vehicle acceleration typically occurs at traffic lights, intersections, or congested sections within urban streets, where high densities of pedestrians and vehicles pose a direct threat to respiratory health due to PM<sub>2.5</sub> dispersion. Computational Fluid Dynamics (CFD) simulatio...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-02-01
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| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/16/3/268 |
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| Summary: | Vehicle acceleration typically occurs at traffic lights, intersections, or congested sections within urban streets, where high densities of pedestrians and vehicles pose a direct threat to respiratory health due to PM<sub>2.5</sub> dispersion. Computational Fluid Dynamics (CFD) simulations, combined with the Dynamic Mode Decomposition (DMD) method, are used to analyze the dynamic characteristics of PM<sub>2.5</sub> dispersion during vehicle acceleration. The DMD method can effectively analyze the dynamic change in pollutant concentration in an unsteady flow field and clarify the influence mechanism of vehicle acceleration on pollutant dispersion. The results indicate that PM<sub>2.5</sub> dispersion during the initial stage of acceleration is primarily influenced by low-frequency and large-scale flows, such as exhaust emissions, natural wind, and trailing vortices. In the middle stage, PM<sub>2.5</sub> dispersion tends to stabilize, while in the final stage, high-frequency modes dominate, and intense flow field fluctuations significantly enhance PM<sub>2.5</sub> dispersion. Furthermore, the analysis reveals the critical role of upward and downward airflow phenomena around the vehicle in driving PM<sub>2.5</sub> dispersion. This study offers a new perspective on the dispersion characteristics of PM<sub>2.5</sub> under unsteady flow conditions in urban streets and provides a scientific basis for developing speed management strategies to mitigate the impact of pollutant dispersion. |
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| ISSN: | 2073-4433 |