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Modeling near-road air quality using a computational fluid dynamics model, CFD-VIT-RIT.
1Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, USA.
Environmental Science & Technology
|November 20, 2009
Summary
Roadway design significantly impacts near-road air pollution by influencing turbulent mixing. Incorporating vehicle-induced turbulence (VIT) and road-induced turbulence (RIT) into models improves air quality predictions.
Area of Science:
- Environmental Science
- Atmospheric Chemistry
- Computational Fluid Dynamics
Background:
- Dilution is key to near-road air pollutant concentrations.
- Turbulent mixing mechanisms (vehicle-induced, road-induced, atmospheric boundary layer) are crucial.
- Roadway designs influence vehicle-induced turbulence (VIT) and road-induced turbulence (RIT).
Purpose of the Study:
- Advance understanding of turbulent mixing on and near roadways.
- Incorporate detailed treatment of VIT and RIT into computational fluid dynamics (CFD).
- Simulate spatial gradients of carbon monoxide (CO) near highways.
Main Methods:
- Developed a CFD model incorporating VIT and RIT (CFD-VIT-RIT).
- Applied the model to simulate CO concentrations near two major highways.
- Compared model results with field measurements and other models (CALINE4, CFD without VIT/RIT).
Main Results:
- CFD-VIT-RIT significantly improved modeling predictions for CO.
- Improvements were particularly notable for vertical gradients and seasonal variations.
- Model results showed better agreement with field measurements compared to other models.
Conclusions:
- Roadway design is a significant factor in near-road air pollution.
- Mitigating near-road pollution through roadway design should be integrated into air quality and transportation management.
- CFD-VIT-RIT is a valuable tool for roadway design processes.
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