Effects of building aspect ratio, diurnal heating scenario, and wind speed on reactive pollutant dispersion in urban street canyons

2012 ◽  
Vol 24 (12) ◽  
pp. 2091-2103 ◽  
Author(s):  
Nelson Y.O. Tong ◽  
Dennis Y.C. Leung
Keyword(s):  
Wind Speed ◽  
Aspect Ratio ◽  
Pollutant Dispersion ◽  
Street Canyons ◽  
Urban Street ◽  
Urban Street Canyons ◽  
Reactive Pollutant

Characteristics of flow and reactive pollutant dispersion in urban street canyons

2015 ◽  
Vol 108 ◽  
pp. 20-31 ◽  
Author(s):  
Soo-Jin Park ◽  
Jae-Jin Kim ◽  
Minjoong J. Kim ◽  
Rokjin J. Park ◽  
Hyeong-Bin Cheong
Keyword(s):  
Pollutant Dispersion ◽  
Street Canyons ◽  
Urban Street ◽  
Urban Street Canyons ◽  
Reactive Pollutant

Development and Validation of a Thermodynamic Model for Predicting Traffic-Related Pollutants Dispersion in Urban Street Canyons under Low Wind Speed Conditions

2012 ◽  
Vol 157-158 ◽  
pp. 710-713
Author(s):  
Guo Hua Gao ◽  
Jing Liu ◽  
Fei Ma ◽  
Wei Dong Luo
Keyword(s):  
Wind Speed ◽  
Thermodynamic Model ◽  
Street Canyon ◽  
Pollutant Dispersion ◽  
Shielding Effect ◽  
Street Canyons ◽  
Urban Street ◽  
Low Wind Speed ◽  
Urban Street Canyons ◽  
Pollutants Dispersion

To study the thermal effects on pollutant dispersion in the street canyon, a thermodynamic model is developed in this paper to predict surface temperature in street canyon environment, which can offer boundary conditions for CFD model. This model considered the shielding effect of buildings on solar radiation, the multi-reflection of radiation between building surfaces and the road. Furthermore, sensible heat exchange between the canyon space and the overlaying atmosphere was also modeled based on the classical theory of dynamics of atmospheric boundary layer. The reliability of this model is validated through a field measurement. Based on the thermodynamic model, a coupled calculation method is presented to predict traffic-related pollutants dispersion in urban street canyons under low wind speed conditions.

Large-Eddy Simulation of Reactive Pollutant Dispersion Over Street Canyons of Different Aspect Ratios

2014 ◽  
Author(s):  
T. Z. Du ◽  
Chun-Ho Liu ◽  
Y. B. Zhao
Keyword(s):  
Aspect Ratio ◽  
Large Eddy Simulation ◽  
Chemical Reactions ◽  
Pollutant Dispersion ◽  
Pollutant Removal ◽  
Street Canyons ◽  
Eddy Simulation ◽  
Aspect Ratios ◽  
Large Eddy ◽  
Reactive Pollutant

In urban areas, pollutants are emitted from vehicles then disperse from the ground level to the downstream urban canopy layer (UCL) under the effect of the prevailing wind. For a hypothetical urban area in the form of idealized street canyons, the building-height-to-street-width (aspect) ratio (AR) changes the ground roughness which in turn leads to different turbulent airflow features. Turbulence is considered an important factor for the removal of reactive pollutants by means of dispersion/dilution and chemical reactions. Three values of aspect ratio, covering most flow scenarios of urban street canyons, are employed in this study. The pollutant dispersion and reaction are calculated using large-eddy simulation (LES) with chemical reactions. Turbulence timescale and reaction timescale at every single point of the UCL domain are calculated to examine the pollutant removal. The characteristic mechanism of reactive pollutant dispersion over street canyons will be reported in the conference.

Pollutant dispersion and thermal effects in urban street canyons

1996 ◽  
Vol 30 (15) ◽  
pp. 2659-2677 ◽  
Author(s):  
Jean-François Sini ◽  
Sandrine Anquetin ◽  
Patrice G. Mestayer
Keyword(s):  
Thermal Effects ◽  
Pollutant Dispersion ◽  
Street Canyons ◽  
Urban Street ◽  
Urban Street Canyons

Buoyant wind-driven pollutant dispersion and recirculation behaviour in wedge-shaped roof urban street canyons

2019 ◽  
Vol 26 (8) ◽  
pp. 8289-8302 ◽  
Author(s):  
Xiaochun Zhang ◽  
Zijian Zhang ◽  
Guokai Su ◽  
Haowen Tao ◽  
Wenhao Xu ◽  
...  
Keyword(s):  
Pollutant Dispersion ◽  
Street Canyons ◽  
Urban Street ◽  
Urban Street Canyons
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