Effects of the urban canopy on natural ventilation using LES*

Mechanical building cooling increasingly contributes to global energy use. Natural ventilation and cooling, where wind and buoyancy forces drive outside air through a building, can offer an efficient alternative solution. Understanding the potential for natural ventilation can inform urban planning for cooler cities, as well as building systems design. One challenge of quantifying natural ventilation potential (NVP) is capturing the significant influence of the urban canopy wind flow pattern.

We use large-eddy simulations (LESs) to simulate wind flow through several idealized urban canopy configurations, assuming neutral surface layer conditions. The objective is quantifying the effect of the urban geometry on NVP. The idealized configurations vary building spacing, staggering, skewness, and height uniformity. We will quantify NVP using the wind speed and direction near the facades, assuming one-sided natural ventilation. Future work will investigate the effect of buoyancy, considering non-neutral outdoor conditions and indoor/outdoor temperature differences.