Wind tunnel study on the spatio-temporal behaviour of pollutant dispersion in 3D street canyons using PIV and DMD

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F25%3A00638757" target="_blank" >RIV/61388998:_____/25:00638757 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0360132325008819?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0360132325008819?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.buildenv.2025.113405" target="_blank" >10.1016/j.buildenv.2025.113405</a>

Result language

angličtina

Original language name

Wind tunnel study on the spatio-temporal behaviour of pollutant dispersion in 3D street canyons using PIV and DMD

Original language description

Street canyons are a common feature of urban environments. They are also arguably the most polluted areas due to the high volume of traffic and low fresh air supply for ventilation. Therefore, a detailed understanding of the processes within the street canyon is crucial for ensuring good air quality in urban areas. In this study, we investigate the flow and pollutant dispersion in four model street canyons with different morphologies by performing time-resolved Particle Image Velocimetry (PIV) and pollutant concentration measurements in a wind tunnel. The analysed street canyons have different aspect ratios and were surrounded by higher or lower buildings, i.e. street canyons with a higher or lower aspect ratio. First, we present an approach to determine pollutant concentrations from PIV data and show that the method can be reliably used to measure planar turbulent pollutant fluxes. Differences in the concentration and flow fields at different levels were observed, indicating the importance of considering the three-dimensionality of street canyons. It was found that turbulent pollution fluxes play a dominant role in pollutant transport at the roof level when street canyons are surrounded by buildings of the same height. Conversely, advection dominates at roof level when a street canyon is surrounded by buildings of different heights. The quadrant analysis of vertical momentum and pollution fluxes shows high correlations between sweeps and entrainment of clean air, especially for street canyons surrounded by buildings of different heights. We apply the dynamic mode decomposition (DMD) technique, a data-driven algorithm, to extract dynamically relevant coherent structures of the flow and pollutant concentration from the data. The DMD results show that coherent structures near the roof and ground play a crucial role in the ventilation of street canyons.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

<a href="/en/project/GA22-14608S" target="_blank" >GA22-14608S: The role of coherent structures' dynamics on scalar transport and dispersion in the urban canopy layer</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Building and Environment

ISSN

0360-1323

e-ISSN

1873-684X

Volume of the periodical

283

Issue of the periodical within the volume

September

Country of publishing house

GB - UNITED KINGDOM

Number of pages

14

Pages from-to

113405

UT code for WoS article

001548106500002

EID of the result in the Scopus database

2-s2.0-105010840907