US EPA

3871369 

Journal Article 

The influence of building geometry on street canyon air flow: Validation of large eddy simulations against wind tunnel experiments 

Llaguno-Munitxa, M; Bou-Zeid, E; Hultmark, M 

2017 

1 

Journal of Wind Engineering and Industrial Aerodynamics
ISSN: 0167-6105
EISSN: 1872-8197 

165 

115-130 

10.1016/j.jweia.2017.03.007 

WOS:000401201000011 

This study investigates the effect of roof and facade geometry on the mean wind flow and turbulence in street canyons, as well as the ability of numerical simulation techniques in capturing the flow features. Numerical experiments, using the large eddy simulation FLUENT code, have been conducted under neutral stability conditions to test 5 building geometries: i) flat roof, ii) pitched roof, iii) round roof, iv) terraced building and v) building with balconies. Wind tunnel experiments were also conducted for the first three geometries. The simulation and experimental setups were closely matched and both featured configurations consisting of seven building arrays. The results from the physical and numerical experiments concur that (i) in-canyon vortex dynamics and over-canopy flow conditions, are strongly dependent on the geometric features of the buildings, and (ii) pitched and round roof geometries increase in-canyon mean and turbulent velocities, as well as the depth of the shear layer. The findings provide novel insight on the sensitivity of the flow and turbulence fields, as well as the simulation quality, to urban topography, inflow conditions, and the Reynolds number. They also underline the influence on the flow of small-scale features such as balconies, which are often ignored in prior literature. 

Building geometry; Large Eddy simulations; Street canyon design; Urban ventilation; Wind tunnel experiments