Street-canyon pollution with respect to urban-array complexity: The role of lateral and mean pollution fluxes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10378197" target="_blank" >RIV/00216208:11320/18:10378197 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/61388998:_____/18:00489573

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=MHOs5e7Kcn" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=MHOs5e7Kcn</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.buildenv.2018.04.036" target="_blank" >10.1016/j.buildenv.2018.04.036</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Street-canyon pollution with respect to urban-array complexity: The role of lateral and mean pollution fluxes

Popis výsledku v původním jazyce

The prediction of pollution within street canyons remains challenging due to the complexity of turbulent flows in urban environments. To improve our understanding of these flows and their relation to the ventilation of street-canyons, we studied pollution fluxes through all street-canyon openings and their balance with respect to urban-array complexity using large-eddy simulations (LES). We validated the LES with wind-tunnel measurements using mean velocities and concentrations and the mean total and turbulent pollution fluxes at the top and lateral openings of the street canyons with either uniform or nonuniform heights and pitched roofs. The LES confirm and extend recent findings about the importance of mean horizontal pollution fluxes for pollutant transport within a street network. The mean fluxes have at least the same dominance as the turbulent ones in case of lateral openings. In case of top openings, the mean fluxes clearly dominate if openings at the roof eaves are selected. While pollutant removal and entrainment through lateral openings are negligible in case of uniform canyons, they are notable in case of nonuniform canyons. We demonstrate that urban roof height nonuniformity does not necessarily enhance the street-canyon ventilation because it worsens (by a factor of 1.1) or improves (by a factor of 1.5) the ventilation compared with the urban uniform height.

Název v anglickém jazyce

Street-canyon pollution with respect to urban-array complexity: The role of lateral and mean pollution fluxes

Popis výsledku anglicky

The prediction of pollution within street canyons remains challenging due to the complexity of turbulent flows in urban environments. To improve our understanding of these flows and their relation to the ventilation of street-canyons, we studied pollution fluxes through all street-canyon openings and their balance with respect to urban-array complexity using large-eddy simulations (LES). We validated the LES with wind-tunnel measurements using mean velocities and concentrations and the mean total and turbulent pollution fluxes at the top and lateral openings of the street canyons with either uniform or nonuniform heights and pitched roofs. The LES confirm and extend recent findings about the importance of mean horizontal pollution fluxes for pollutant transport within a street network. The mean fluxes have at least the same dominance as the turbulent ones in case of lateral openings. In case of top openings, the mean fluxes clearly dominate if openings at the roof eaves are selected. While pollutant removal and entrainment through lateral openings are negligible in case of uniform canyons, they are notable in case of nonuniform canyons. We demonstrate that urban roof height nonuniformity does not necessarily enhance the street-canyon ventilation because it worsens (by a factor of 1.1) or improves (by a factor of 1.5) the ventilation compared with the urban uniform height.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10509 - Meteorology and atmospheric sciences

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

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

—

Svazek periodika

138

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

221-234

Kód UT WoS článku

000436887200019

EID výsledku v databázi Scopus

2-s2.0-85046513760