A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Impacts of shape and height of upstream roof on airflow and pollutant dispersion inside an urban street canyon
A two-dimensional numerical model for simulating flow and pollutant dispersion in an urban street canyon is firstly developed using the FLUENT code and then validated against the wind tunnel results. After this, the flow field and pollutant dispersion inside an urban street canyon with aspect ratio W/H = 1 are examined numerically considering five different shapes (vaulted, trapezoidal, slanted, upward wedged, and downward wedged roofs) as well as three different roof height to building height ratios (ZH/H = 1/6, 1/3, and 1/2) for the upstream building roof. The results obtained reveal that the shape and height of an upstream roof have significant influences on flow pattern and pollutant distribution in an urban canyon. A large single clockwise vortex is generated in the canyon for the vaulted upstream roof at ZH/H = 1/6, 1/3, and 1/2, the trapezoidal and downward wedged roofs at ZH/H = 1/6 and 1/3, and the slanted and upward wedged roofs at ZH/H = 1/6, while a main clockwise vortex and a secondary counterclockwise vortex are established for the trapezoidal and downward wedged roofs at ZH/H = 1/2 and the slanted and upward wedged roofs at ZH/H = 1/3 and 1/2. In the one-vortex flow regime, the clockwise vortex moves upward and grows in size with increasing upstream roof height for the vaulted, trapezoidal, and downward wedged roofs. In the two-vortex flow regime, the size and rotational velocity of both upper clockwise and lower counterclockwise vortices increase with the upstream roof height for the slanted and upward wedged roofs. At ZH/H = 1/6, the pollution levels in the canyon are close among all the upstream roof shapes studied. At ZH/H = 1/3, the pollution levels in the canyon for the upward wedged roof and slanted roof are much higher than those for the vaulted, trapezoidal, and downward wedged roofs. At ZH/H = 1/2, the lowest pollution level appears in the canyon for the vaulted upstream roof, while the highest pollution level occurs in the canyon for the upward wedged roof.
Impacts of shape and height of upstream roof on airflow and pollutant dispersion inside an urban street canyon
A two-dimensional numerical model for simulating flow and pollutant dispersion in an urban street canyon is firstly developed using the FLUENT code and then validated against the wind tunnel results. After this, the flow field and pollutant dispersion inside an urban street canyon with aspect ratio W/H = 1 are examined numerically considering five different shapes (vaulted, trapezoidal, slanted, upward wedged, and downward wedged roofs) as well as three different roof height to building height ratios (ZH/H = 1/6, 1/3, and 1/2) for the upstream building roof. The results obtained reveal that the shape and height of an upstream roof have significant influences on flow pattern and pollutant distribution in an urban canyon. A large single clockwise vortex is generated in the canyon for the vaulted upstream roof at ZH/H = 1/6, 1/3, and 1/2, the trapezoidal and downward wedged roofs at ZH/H = 1/6 and 1/3, and the slanted and upward wedged roofs at ZH/H = 1/6, while a main clockwise vortex and a secondary counterclockwise vortex are established for the trapezoidal and downward wedged roofs at ZH/H = 1/2 and the slanted and upward wedged roofs at ZH/H = 1/3 and 1/2. In the one-vortex flow regime, the clockwise vortex moves upward and grows in size with increasing upstream roof height for the vaulted, trapezoidal, and downward wedged roofs. In the two-vortex flow regime, the size and rotational velocity of both upper clockwise and lower counterclockwise vortices increase with the upstream roof height for the slanted and upward wedged roofs. At ZH/H = 1/6, the pollution levels in the canyon are close among all the upstream roof shapes studied. At ZH/H = 1/3, the pollution levels in the canyon for the upward wedged roof and slanted roof are much higher than those for the vaulted, trapezoidal, and downward wedged roofs. At ZH/H = 1/2, the lowest pollution level appears in the canyon for the vaulted upstream roof, while the highest pollution level occurs in the canyon for the upward wedged roof.
Impacts of shape and height of upstream roof on airflow and pollutant dispersion inside an urban street canyon
Huang, Yuan-Dong (author) / He, Wen-rong (author) / Kim, Chang-Nyung (author)
ESPR - Environmental Science and Pollution Research ; 22 ; 2117-2137
2015
21 Seiten
Article (Journal)
English
Analysis of pollutant dispersion in an urban street canyon
| Online Contents | 1999
Analysis of pollutant dispersion in an urban street canyon
| Tema Archive | 1999
Analysis of pollutant dispersion in an urban street canyon
| Online Contents | 1999