Application of Improved CFD Modeling for Prediction and Mitigation of Traffic-Related Air Pollution Hotspots in a Realistic Urban Street

Abstract

The correct prediction of air pollutants dispersed in urban areas is of paramount importance to safety, public health and a sustainable environment. Vehicular traffic is one of the main sources of nitrogen oxides (NO x ) and particulate matter (PM), strongly related to human morbidity and mortality. In this study, the pollutant level and distribution in a section of one of the main road arteries of Antwerp (Belgium, Europe) are analyzed. The assessment is performed through computational fluid dynamics (CFD), acknowledged as a powerful tool to predict and study dispersion phenomena in complex atmospheric environments. The two main traffic lanes are modeled as emitting sources and the surrounding area is explicitly depicted. A Reynolds-averaged Navier-Stokes (RANS) approach specific for Atmospheric Boundary Layer (ABL) simulations is employed. After a validation on a wind tunnel urban canyon test case, the dispersion within the canopy of two relevant urban pollutants, nitrogen dioxide (NO 2 ) and particulate matter with an aerodynamic diameter smaller than 10 µm (PM 10 ), is studied. An experimental field campaign led to the availability of wind velocity and direction data, as well as PM 10 concentrations in some key locations within the urban canyon. To accurately predict the concentration field, a relevant dispersion parameter, the turbulent

Urban Obstacles Influence on Street Canyon Ventilation: A Brief Review

“…Wind catchers have been used to improve indoor air quality, however, some recent studies show that wind catchers can be effectively employed to improve outdoor air quality as well [31,32]. Located at the roof of certain buildings facing the main street, wind catchers offer a passive method of diluting the pollutant concentrations and increasing wind speed for targeted areas within urban street canyons.…”

“…Some studies have shown that lift-up building design can ally provide a comfortable microclimate in summer conditions, while not causing a cold stress in the winter [33]. Although the study characterised different building s such as the 'L', 'U', 'I' and the '□' shaped buildings in different orientations (Figure wind flow (at the pedestrian level) seems to be more altered due to the shape and ar ment of the core and column supports rather than the shape of the building itself [ Employment of wind catchers appear to reduce concentration levels by up to 37% in some pedestrian-level areas, by modifying the air entrainment in the street canyons resulting in a more efficient dilution process [31]. The benefits of wind catchers are that they can be targeted for specific buildings, while not taking up space within the urban canyon at street levels.…”

Wind Environment Simulation Accuracy in Traditional Villages with Complex Layouts Based on CFD

“…CFD simulation was used to optimize the circulating air volume, return air angle, and exhaust volume of the circulating system. Lauriks et al [21] used CFD to analyze the level and distribution of pollutants in a part of Antwerp's main road artery (Belgium, Europe). Erfan et al [22] investigated the influence of the crosssectional shape of a building on the diffusion of air pollutants around the isolated building.…”

Iterative symbolic regression for learning transport equations

“…With continued growth of computational power and advances in CFD techniques, even complex models can be done on commodity hardware. Thus, CFD modeling is routinely applied in several fields of science and engineering such as chemistry, 2,3 materials, 4 fluid flow and heat transfer, 5,6 biology, 7 drug delivery, 8 semiconductors, 9 environmental engineering, 10,11 biomedical engineering, 12 and aeronautics 13…”