Can deeper street canyons ventilate better? An analysis of roof geometries and aspect ratios with a focus on pollutant dynamics

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F25%3A00603891" target="_blank" >RIV/61388998:_____/25:00603891 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/25:10495587

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0360132325000101?dgcid=author" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0360132325000101?dgcid=author</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.buildenv.2025.112528" target="_blank" >10.1016/j.buildenv.2025.112528</a>

Result language

angličtina

Original language name

Can deeper street canyons ventilate better? An analysis of roof geometries and aspect ratios with a focus on pollutant dynamics

Original language description

This study addresses ventilation and pollutant transport in urban street canyons with different roof geometries and canyon aspect ratios using Detached Eddy Simulation (DES). First, we validated the DES through wind tunnel experiments on flow and pollutant dispersion in two different street canyon models with different aspect ratios (AR1 and AR2), but both with flat roofs (F-AR1 and F-AR2). Then we performed the DES on two more models with the same aspect ratios as the previous ones but with pitched roofs (P-AR1 and P-AR2). The results show that deeper street canyons (F-AR2 and P-AR2) are more efficiently ventilated at higher levels than shallower street canyons (F-AR1 and P-AR1), mainly due to the outflow of pollutants through lateral openings. Street canyons with pitched roofs (P-AR1 and P-AR2) improve ventilation by a factor of 2, as pollutant removal by advection through the top and side openings is significantly higher than in street canyons with flat roofs. We have found that the P-AR2 street canyon is the best configuration for adequate pollutant ventilation in the pedestrian zone. This configuration provides cleaner air at the leeward and windward walls compared to the street canyon P-AR1. The dynamic mode decomposition (DMD) shows that the propagation of turbulent coherent structures correlates with the propagation of concentration structures and pollutant advection. However, advection improves the ventilation of street canyons compared to turbulent coherent structures, especially through lateral openings. These results provide valuable insights for the design of street canyons and suggest that deeper street canyons with pitched roofs can provide better air quality in the pedestrian zone and especially at higher street levels.

Czech name

—

Czech description

—

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

270

Issue of the periodical within the volume

February

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

112528

UT code for WoS article

001410178400001

EID of the result in the Scopus database

2-s2.0-85214328341