NUMERICAL STUDY OF AIR POLLUTANTS DISPERSION IN AN URBAN STREET CANYON

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dc.contributor.authorPARAJULI, BIBEK
dc.contributor.authorLOHANI, BINAYAK
dc.contributor.authorKHADKA, BIRAJ
dc.date.accessioned2023-07-21T05:05:32Z
dc.date.available2023-07-21T05:05:32Z
dc.date.issued2023-03
dc.descriptionAir pollution is one of the major challenges humankind is facing in the 21st century. Rapid urbanization, industrialization, increasing number of vehicles, etc are some of the problems faced by the major cities which impact the lives of many people due to air pollution. The air quality index (AQI), which measures the concentration of different elements of air pollution is increasing day by dayen_US
dc.description.abstractThe alarming increase of hazardous pollutants in South Asian cities such as Kathmandu, Delhi, Mumbai, Dhaka, etc risks the life of every individual there. The situation worsens especially, in the winter rising the air quality index to life-risking situations. A proper scientific study and modeling of the pollutants are necessary in order to manage the pollution level properly. A major source in the production of such harmful pollutants is vehicles and industries. A Computational Fluid Dynamics (CFD) approach is proposed to model the pollutants emitted by vehicles using different Reynolds Averaged Navier Stokes (RANS) turbulence models in the street canyon setup. The primary aim of the study is to understand the effect of turbulence on the transport of gaseous pollutants in the street canyon. This is accomplished by developing a turbulent steady-state solver for the passive transport of pollutants. RNG k − ε model performed best among other turbulence models with mean FB -0.105, NMSE 0.045, FAC2 0.915 and R 0.93 which is validated with the experimental data. An increase in dispersion of pollutants by 51.4% for AR=0.2 and by 42.33% for AR=0.5 was observed in comparison to AR=1. Street canyons with a low aspect ratio of 0.2 effectively assisted the escape of pollutants. Higher aspect ratios result in flow fields that are more constrained and stagnant, which restricts the dispersion of pollutants. Further, the balconied building lowered the concentration of gaseous pollutants in specific regions only and reduced the exchange concentration flux of pollutants with atmospheric air above the street canyon. Higher wind speeds allowed the concentration to disperse more effectively in Baghbazar’s street canyon, resulting in lower concentrations of pollutantsen_US
dc.identifier.urihttps://elibrary.tucl.edu.np/handle/20.500.14540/18565
dc.language.isoenen_US
dc.publisherIOE Pulchowk Campusen_US
dc.relation.ispartofseries;B-08-BAS-2018/23
dc.subjectpollutanten_US
dc.subjectCFDen_US
dc.titleNUMERICAL STUDY OF AIR POLLUTANTS DISPERSION IN AN URBAN STREET CANYONen_US
dc.typeReporten_US
local.academic.levelBacheloren_US
local.affiliatedinstitute.titlePulchowk Campusen_US
local.institute.titleInstitute of Engineeringen_US
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