CFD simulation of outdoor ventilation of generic urban configurations with different urban densities and equal and unequal street widths

Outdoor ventilation is very important for a healthy and livable urban environment. It is strongly influenced by wind speed and direction, which in turn are affected by urban morphology. This paper first provides a detailed review of the literature for CFD studies of outdoor ventilation for generic u...

Full description

Saved in:
Bibliographic Details
Published in:Building and environment 2015-10, Vol.92, p.152-166
Main Authors: Ramponi, Rubina, Blocken, Bert, de Coo, Laura B, Janssen, Wendy D
Format: Article
Language:English
Subjects:
Computational fluid dynamics
Computer simulation
Flow rate
Mathematical models
Outdoor
Streets
Ventilation
Wind direction
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Outdoor ventilation is very important for a healthy and livable urban environment. It is strongly influenced by wind speed and direction, which in turn are affected by urban morphology. This paper first provides a detailed review of the literature for CFD studies of outdoor ventilation for generic urban configurations. The review indicates that there is a clear lack of studies for urban configurations where not all parallel streets have equal street widths. Next, the paper presents Computational Fluid Dynamics (CFD) simulations of outdoor ventilation for generic configurations with parallel streets of equal and unequal street widths. The 3D steady RANS equations with the standard k- model and the passive scalar transport equation are used to calculate the effective local mean age of air at pedestrian level as an indicator of pollutant removal efficiency. The study is based on grid-convergence analysis and on validation with previously published wind-tunnel measurements. The influence of a central and wider main street on the wind-velocity pattern and on the effective local mean age of air of the surrounding area is analyzed for different wind directions. For wind directions oblique or perpendicular to the main street, the presence of this main street generally improves the ventilation efficiency because the main street acts as a sink of clean air. However, this is generally not the case for the parallel wind direction, where the higher flow rate through the main street reduces the flow rates through the parallel narrower streets, negatively affecting their ventilation efficiency.
ISSN:0360-1323
DOI:10.1016/j.buildenv.2015.04.018