TY - JOUR

T1 - On the effects of lateral openings on courtyard ventilation and pollution

T2 - A large-eddy simulation study

AU - Gronemeier, Tobias

AU - Sühring, Matthias

N1 - Funding Information: This research was part of the MOSAIK project. MOSAIK is funded by the German Federal Ministry of Education and Research (BMBF) under grant 01LP1601A within the framework of Research for Sustainable Development (FONA; www.fona.de). The publication of this article was funded by the Open Access fund of Leibniz University Hannover.

PY - 2019/2/1

Y1 - 2019/2/1

N2 - Courtyards are an omnipresent feature within the urban environment. Residents often use courtyards as recreation areas, which makes them crucial for the physical and psychological comfort of the urban population. However, considering that courtyards represent enclosed cavities, they are often poorly ventilated spaces and pollutants from neighboring traffic, once entrained, can pose a serious threat to human health. Here, we studied the effects of lateral openings on courtyard pollution and ventilation. Therefore, we performed a set of large-eddy simulations for idealized urban environments with different courtyard configurations. While pollutant concentration and ventilation are barely modified by lateral openings for wide courtyards, lateral openings have a significant effect on the mean concentration, the number of high-concentration events and the ventilation within narrower and deeper courtyards. The impacts of lateral openings on air quality within courtyards strongly depend on their orientation with respect to the flow direction, as well as on the upstream flow conditions and upstream building configuration. We show that lateral openings, in most cases, have a negative impact on air quality; nevertheless, we also present configurations where lateral openings positively impact the air quality within courtyards. These outcomes may certainly contribute to improve future urban planning in terms of health protection.

AB - Courtyards are an omnipresent feature within the urban environment. Residents often use courtyards as recreation areas, which makes them crucial for the physical and psychological comfort of the urban population. However, considering that courtyards represent enclosed cavities, they are often poorly ventilated spaces and pollutants from neighboring traffic, once entrained, can pose a serious threat to human health. Here, we studied the effects of lateral openings on courtyard pollution and ventilation. Therefore, we performed a set of large-eddy simulations for idealized urban environments with different courtyard configurations. While pollutant concentration and ventilation are barely modified by lateral openings for wide courtyards, lateral openings have a significant effect on the mean concentration, the number of high-concentration events and the ventilation within narrower and deeper courtyards. The impacts of lateral openings on air quality within courtyards strongly depend on their orientation with respect to the flow direction, as well as on the upstream flow conditions and upstream building configuration. We show that lateral openings, in most cases, have a negative impact on air quality; nevertheless, we also present configurations where lateral openings positively impact the air quality within courtyards. These outcomes may certainly contribute to improve future urban planning in terms of health protection.

KW - Courtyard

KW - Lagrangian particle model

KW - Large-eddy simulation

KW - Pollution

KW - Urban environment

KW - Ventilation

UR - http://www.scopus.com/inward/record.url?scp=85061266556&partnerID=8YFLogxK

U2 - 10.15488/4531

DO - 10.15488/4531

M3 - Article

AN - SCOPUS:85061266556

VL - 10

JO - Atmosphere

JF - Atmosphere

SN - 2073-4433

IS - 2

M1 - 63

ER -