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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10509 - Meteorology and atmospheric sciences

Projekt

<a href="/cs/project/GA22-14608S" target="_blank" >GA22-14608S: Role dynamiky koherentních struktur na přenos a rozptyl skaláru v městském baldachýnu</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Building and Environment

ISSN

0360-1323

e-ISSN

1873-684X

Svazek periodika

283

Číslo periodika v rámci svazku

September

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

113405

Kód UT WoS článku

001548106500002

EID výsledku v databázi Scopus

2-s2.0-105010840907