Capability of air exchange rate to predict ventilation of three-dimensional street canyons

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388998%3A_____%2F19%3A00509725" target="_blank" >RIV/61388998:_____/19:00509725 - isvavai.cz</a>

Result on the web

<a href="https://www.epj-conferences.org/articles/epjconf/pdf/2019/18/epjconf_efm18_02042.pdf" target="_blank" >https://www.epj-conferences.org/articles/epjconf/pdf/2019/18/epjconf_efm18_02042.pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/epjconf/201921302042" target="_blank" >10.1051/epjconf/201921302042</a>

Result language

angličtina

Original language name

Capability of air exchange rate to predict ventilation of three-dimensional street canyons

Original language description

As most of the world’s population lives in cities, it is critical to understand dispersion processes of pollutants in urban areas. This study focuses on so called air exchange rate (ACH) index, which is frequently used by numerical studies to determine ventilation of street canyons without a simulation of a pollution source. These studies applied the ACH on idealised 2D street canyons, where the ventilation acts only through the one opening roof top. There are two pertinent questions: i) is the ACH really capable to predict the ventilation of a street canyon without knowing of a pollutant source, and ii) how much the ACH differs between 2D and 3D street canyons? To answer these questions, we performed large-eddy simulations of pollution of complex 3D street canyons from ground-level line sources. We computed ACHs and spatially-average concentrations for three different street canyons and compared these quantities with those from previous studies. Results clearly demonstrate that these quantities strongly depend not only on street-canyon geometry but also on geometry of surrounding buildings. It is also shown that 2D canyon gives unrealistic result for retention of pollutant within an urban street canyon. The ACH might lead to significant underestimation of the street-canyon ventilation if a source would be outside the canyon.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

10509 - Meteorology and atmospheric sciences

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

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

Article name in the collection

EPJ Web of Conferences

ISBN

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ISSN

2100-014X

e-ISSN

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Number of pages

6

Pages from-to

02042

Publisher name

EDP Sciences

Place of publication

Paris

Event location

Prague

Event date

Nov 13, 2018

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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