Impact of source shape on pollutant dispersion in a street canyon in different thermal stabilities

In previous studies of pollutant dispersion around and inside urban street canyons, several kinds source shape assumptions were employed. However, the impact of source shape on pollutant transport in urban street canyon is barely concerned. As a determinant of pollutant distribution, the shape effects of pollutant source should be analyzed carefully. In this study, source shape effects on street canyon pollutant dispersion are investigated using computational fluid dynamics (CFD) approach based on an idealized street canyon model in different thermal stabilities. The line shape source, band shape source and surface shape source assumptions are adopted to represent the widely used source shape patterns. The prediction accuracy of this numerical model is validated against wind tunnel measurement and LES results and is proved to be acceptable. Numerical simulations are performed under neutral and unstable thermal stratifications. Pollutant distribution inside the street canyon and its variation with thermal stability are examined. The results demonstrate that pollutant source shape can significantly alter the distribution of pollutant concentration in the whole street canyon. The most uneven distribution occurs under the surface shape source condition, where more than 60% pollutant is located in the leeward wall zone, but only 19% pollutant is found in the windward wall zone. The surface source assumption contributes to more dispersed distribution. Moreover, different source shape assumptions lead to distinct characteristics of pollutant residue in the street canyon, especially in the near-ground-zone. Also, the variation of pollutant residue with the thermal stability is greatly influenced by the source shape configuration. The source shape effect should not be neglected in future street canyon environment studies. The new findings present in this study can improve the understanding of pollutant dispersion characteristics in urban street canyons, and benefit architects, city-planners and policy makers to achieve optimized solution for urban air pollution.


Abhijith, K.V., Kumar, P., Gallagher, J., McNabola, A., Baldauf, R., Pilla, F., Broderick, B., Di Sabatino, S., Pulvirenti, B., 2017. Air pollution abatement performances of green infrastructure in open road and built-up street canyon environments – a review. Atmos. Environ. 162, 71–86.

Ai, Z.T., Mak, C.M., 2017. CFD simulation of flow in a long street canyon under a perpendicular wind direction: Evaluation of three computational settings. Build. Environ. 114, 293–306.

Allegrini, J., Carmeliet, J., Dorer, V., 2013. Wind tunnel measurements of buoyant flows in street canyons. Build. Environ. 59 (328), 315–326.

Allegrini, J., Dorer, V., Carmeliet, J., 2014. Buoyant flows in street canyons: validation of CFD simulations with wind tunnel measurements. Build. Environ. 72, 63–74.

Amato, F., Schaap, M., Reche, C., Querol, X., 2013. Road Traffic: A Major Source of Particulate Matter in Europe.

Buccolieri, R., Gromke, C., Sabatino, S.D., Ruck, B., 2009. Aerodynamic effects of trees on pollutant concentration in street canyons. Sci. Total Environ. 407 (19), 5247–5256.

Buccolieri, R., Santiago, J.-L., Rivas, E., Sanchez, B., 2018. Review on urban tree modelling in CFD simulations: aerodynamic, deposition and thermal effects. Urban For. Urban Green. 31, 212–220.

Cheng, W., Liu, C.-H., Leung, D.Y., 2009. On the correlation of air and pollutant exchange for street canyons in combined wind-buoyancy-driven flow. Atmos. Environ. 43 (24), 3682–3690.

Cheng, W.C., Liu, C.-H., 2011. Large-eddy simulation of turbulent transports in urban street canyons in different thermal stabilities. J. Wind Eng. Ind. Aerodyn. 99 (4), 434–442.

Dai, Y., Mak, C.M., Ai, Z., Hang, J., 2018. Evaluation of computational and physical parameters influencing CFD simulations of pollutant dispersion in building arrays. Build. Environ. 137, 90–107.

de_Richter, R., Ming, T., Davies, P., Liu, W., Caillol, S., 2017. Removal of non-CO2 greenhouse gases by large-scale atmospheric solar photocatalysis. Prog. Energy Combust. Sci. 60, 68–96.

Dou, H., Ming, T., Li, Z., Peng, C., Zhang, C., Fu, X., 2018. Numerical simulation of pollutant dispersion characteristics in a three-dimensional urban traffic system. Atmos. Pollut. Res. 9 (4), 735–746.

Fernando, H.J., Zajic, D., Di Sabatino, S., Dimitrova, R., Hedquist, B., Dallman, A., 2010. Flow, turbulence, and pollutant dispersion in urban atmospheres. Phys. Fluids 22 (5), 051301.

Gallagher, J., Lago, C., 2019. How parked cars affect pollutant dispersion at street level in an urban street canyon? A CFD modelling exercise assessing geometrical detailing and pollutant decay rates. Sci. Total Environ. 651, 2410–2418.

Garcia-Sanchez, C., Van Tendeloo, G., Gorle, C., 2017. Quantifying inflow uncertainties in RANS simulations of urban pollutant dispersion. Atmos. Environ. 161, 263–273.

Gousseau, P., Blocken, B., Stathopoulos, T., van Heijst, G.J.F., 2015. Near-field pollutant dispersion in an actual urban area: analysis of the mass transport mechanism by highresolution Large Eddy Simulations. Comput. Fluid 114, 151–162.

Gromke, C., Blocken, B., 2015. Influence of avenue-trees on air quality at the urban neighborhood scale. Part II: traffic pollutant concentrations at pedestrian level. Environ. Pollut. 196, 176–184.

Hang, J., Li, Y.G., Sandberg, M., Buccolieri, R., Di Sabatino, S., 2012. The influence of building height variability on pollutant dispersion and pedestrian ventilation in idealized high-rise urban areas. Build. Environ. 56, 346–360.

Hang, J., Xian, Z., Wang, D., Mak, C.M., Wang, B., Fan, Y., 2018. The impacts of viaduct settings and street aspect ratios on personal intake fraction in three-dimensional urban-like geometries. Build. Environ. 143, 138–162.

He, L., Hang, J., Wang, X., Lin, B., Li, X., Lan, G., 2017. Numerical investigations of flow and passive pollutant exposure in high-rise deep street canyons with various street aspect ratios and viaduct settings. Sci. Total Environ. 584–585, 189–206.

Huang, Y.D., Xu, X., Liu, Z.Y., Deng, J.T., Kim, C.N., 2016. Impacts of shape and height of building roof on airflow and pollutant dispersion inside an isolated street canyon. Environ. Forensics 17 (4), 361–379.

Janhäll, S., 2015. Review on urban vegetation and particle air pollution – deposition and dispersion. Atmos. Environ. 105, 130–137.

Kang, Y.-S., Baik, J.-J., Kim, J.-J., 2008. Further studies of flow and reactive pollutant dispersion in a street canyon with bottom heating. Atmos. Environ. 42 (20), 4964–4975.

Kikumoto, H., Ooka, R., 2018. Large-eddy simulation of pollutant dispersion in a cavity at fine grid resolutions. Build. Environ. 127, 127–137.

Kim, J.-J., Baik, J.-J., 2001. Urban street-canyon flows with bottom heating. Atmos. Environ. 35 (20), 3395–3404.

Kim, J., Hong, T., Lee, M., Jeong, K., 2019. Analyzing the real-time indoor environmental quality factors considering the influence of the building occupants' behaviors and the ventilation. Build. Environ. 156, 99–109.

Krecl, P., Targino, A.C., Wiese, L., Ketzel, M., Corrêa, M.D.P., 2016. Screening of shortlived climate pollutants in a street canyon in a mid-sized city in Brazil. Atmos. Pollut. Res. 7 (6), 1022–1036.

Kuuluvainen, H., Poikkimäki, M., Järvinen, A., Kuula, J., Irjala, M., Maso, M.D., Keskinen, J., Timonen, H., Niemi, J.V., Rönkkö, T., 2018. Vertical profiles of lung deposited surface area concentration of particulate matter measured with a drone in a street canyon. Environ. Pollut. 241, 96–105.

Kwak, K.-H., Baik, J.-J., Lee, K.-Y., 2013. Dispersion and photochemical evolution of reactive pollutants in street canyons. Atmos. Environ. 70, 98–107.

Li, X.-X., Britter, R., Norford, L.K., 2016. Effect of stable stratification on dispersion within urban street canyons: a large-eddy simulation. Atmos. Environ. 144, 47–59.

Li, X.-X., Britter, R.E., Koh, T.Y., Norford, L.K., Liu, C.-H., Entekhabi, D., Leung, D.Y., 2010. Large-eddy simulation of flow and pollutant transport in urban street canyons with ground heating. Boundary-Layer Meteorol. 137 (2), 187–204.

Liang, W., Huang, J., Jones, P., Wang, Q., Hang, J., 2018. A zonal model for assessing street canyon air temperature of high-density cities. Build. Environ. 132, 160–169.

Lin, M., Hang, J., Yuguo, L.I., Luo, Z., Sandberg, M., 2014. Quantitative ventilation assessments of idealized urban canopy layers with various urban layouts and the same building packing density. Build. Environ. 79 (8), 152–167.

Lin, Y., Chen, G., Chen, T., Luo, Z., Yuan, C., Gao, P., Hang, J., 2019. The influence of advertisement boards, street and source layouts on CO dispersion and building intake fraction in three-dimensional urban-like models. Build. Environ. 150, 297–321.

Liu, C.-H., Cheng, W., Leung, T.C., Leung, D.Y., 2011. On the mechanism of air pollutant re-entrainment in two-dimensional idealized street canyons. Atmos. Environ. 45 (27), 4763–4769.

Liu, C.-H., Wong, C.C., 2014. On the pollutant removal, dispersion, and entrainment over two-dimensional idealized street canyons. Atmos. Res. 135, 128–142.

Liu, H., Liang, B., Zhu, F., Zhang, B., Sang, J., 2003. A Laboratory model for the flow in urban street canyons induced by bottom heating. Adv. Atmos. Sci. 20 (4), 554–564.

Llaguno-Munitxa, M., Bou-Zeid, E., Hultmark, M., 2017. The influence of building geometry on street canyon air flow: validation of large eddy simulations against wind tunnel experiments. J. Wind Eng. Ind. Aerodyn. 165, 115–130.

Madalozzo, D.M.S., Braun, A.L., Awruch, A.M., Morsch, I.B., 2014. Numerical simulation of pollutant dispersion in street canyons: geometric and thermal effects. Appl. Math. Model. 38 (24), 5883–5909.

Mei, S.-J., Hu, J.-T., Liu, D., Zhao, F.-Y., Li, Y., Wang, H.-Q., 2019. Airborne pollutant dilution inside the deep street canyons subjecting to thermal buoyancy driven flows: effects of representative urban skylines. Build. Environ. 149, 592–606.

Meroney, R.N., Pavageau, M., Rafailidis, S., Schatzmann, M., 1996. Study of line source characteristics for 2-D physical modelling of pollutant dispersion in street canyons. J. Wind Eng. Ind. Aerodyn. 62 (1), 37–56.

Ming, T., Fang, W., Peng, C., Cai, C., de Richter, R., Ahmadi, M., Wen, Y., 2018. Impacts of traffic tidal flow on pollutant dispersion in a non-uniform urban street canyon. Atmosphere 9 (3), 82.

Nosek, Š., Kukačka, L., Jurčáková, K., Kellnerová, R., Jaňour, Z., 2017. Impact of roof height non-uniformity on pollutant transport between a street canyon and intersections. Environ. Pollut. 227, 125–138.

Qu, Y., Milliez, M., Musson-Genon, L., Carissimo, B., 2012. Numerical study of the thermal effects of buildings on low-speed airflow taking into account 3D atmospheric radiation in urban canopy. J. Wind Eng. Ind. Aerodyn. 104, 474–483.

Sanchez, B., Santiago, J.-L., Martilli, A., Palacios, M., Kirchner, F., 2016. CFD modeling of reactive pollutant dispersion in simplified urban configurations with different chemical mechanisms. Atmos. Chem. Phys. 16 (18), 12143–12157.

Santiago, J.-L., Martilli, A., Martin, F., 2017. On dry deposition modelling of atmospheric pollutants on vegetation at the microscale: application to the impact of street vegetation on air quality. Boundary-Layer Meteorol. 162 (3), 451–474.

Tan, Z., Dong, J., Xiao, Y., Tu, J., 2015a. Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions. Atmos. Environ. 119, 95–106.

Tan, Z., Dong, J., Xiao, Y., Tu, J., 2015b. A numerical study of diurnally varying surface temperature on flow patterns and pollutant dispersion in street canyons. Atmos. Environ. 104, 217–227.

Tominaga, Y., Stathopoulos, T., 2018. CFD simulations of near-field pollutant dispersion with different plume buoyancies. Build. Environ. 131, 128–139.

Uehara, Kiyoshi, Murakami, Shuzo, Oikawa, Susumu, Wakamatsu, Shinji, 2000. Wind tunnel experiments on how thermal stratification affects flow in and above urban street canyons. Atmos. Environ. 34 (10), 1553–1562.

Vardoulakis, S., Fisher, B.E.A., Pericleous, K., Gonzalez-Flesca, N., 2003. Modelling air quality in street canyons: a review. Atmos. Environ. 37 (2), 155–182.

Vos, P.E.J., Maiheu, B., Vankerkom, J., Janssen, S., 2013. Improving local air quality in cities: to tree or not to tree? Environ. Pollut. 183, 113–122.

Wang, Q., Fang, W., de Richter, R., Peng, C., Ming, T., 2019. Effect of moving vehicles on pollutant dispersion in street canyon by using dynamic mesh updating method. J. Wind Eng. Ind. Aerodyn. 187, 15–25.

Xia, J., Leung, D.Y., 2001. A concentration correction scheme for Lagrangian particle model and its application in street canyon air dispersion modelling. Atmos. Environ. 35 (33), 5779–5788.

Xie, X., Huang, Z., Wang, J., Xie, Z., 2005. The impact of solar radiation and street layout on pollutant dispersion in street canyon. Build. Environ. 40 (2), 201–212.

Yu, S., Yu, Z., Ma, X., Zhang, G., Feng, G., 2017. Study on the influence of pollution source location on indoor pollutant distribution under different air supply. Procedia Engineering 205, 2623–2630.

Zhang, K., Chen, G., Wang, X., Liu, S., Mak, C.M., Fan, Y., Hang, J., 2019. Numerical evaluations of urban design technique to reduce vehicular personal intake fraction in deep street canyons. Sci. Total Environ. 653, 968–994.

Zhang, Y., Gu, Z., Wah Yu, C., 2018. Review on Numerical Simulation of Airflow and Pollutant Dispersion in Urban Street Canyons under Natural Background Wind Condition.


Atmospheric Pollution Research
  • ISSN: 1309-1042
  • Yayın Aralığı: Yılda 12 Sayı
  • Başlangıç: 2010


Sayıdaki Diğer Makaleler

Multivariate NARX neural network in prediction gaseous emissions within the influent chamber of wastewater treatment plants


Characteristics and sources of VOCs in urban and suburban environments in Shanghai, China, during the 2016 G20 summit

Shanshan ZHENG, Xiaofeng XU, Yunjiang ZHANG, Lingrui WANG, Yifan YANG, Shiguang JİN, Xiaoxiao YANG

Investigation of potential source regions of atmospheric Black Carbon in the data deficit region of the western Himalayas and its foothills

Ashish SONİ, Stefano DECESARİ, Vijay SHRİDHAR, Vignesh PRABHU, Pooja PANWAR, Angela MARİNONİ

Why did ozone levels remain high in Rio de Janeiro during the Brazilian truck driver strike?

Guilherme DANTAS, Bruno SİCİLİANO, Leticia FREİTAS, Eduardo Guedes de SEİXAS, Cleyton M. da SİLVA, Graciela ARBİLLA

Effects of real trees and their structure on pollutant dispersion andflowfieldin an idealized street canyon

Junwei SU, Zhaolin GU, Le WANG, Meimei SONG, Zhourong CAO

Prediction of optimum sampling rates of air quality monitoring stations using hierarchical fuzzy logic control system



Chenrui HAO, Xiaomin XİE, Zhen Huang, Yue HUANG

Spatiotemporal variability of surface extinction coefficient based on twoyear hourly visibility data in mainland China

Fei YE, Disong FU, Zijue SONG, Shuai HAN, Xinlei HAN, Xiangao XİA

Assessment of carbonization of coal as a potential strategy to reduce emissions for domestic applications

Darpan DAS, Suryendu DUTTA, Upendra BHANDARKAR, Virendra SETHİ

Carcinogenic and non-carcinogenic risks from PM10-and PM2.5-Bound metals in a critically polluted coal mining area

Debananda ROY, Gurdeep Singh GREWAR, Yong-Chil SEO