uDALES 1.0: a large-eddy simulation model for urban environments

• Published in: Geoscientific Model Development 2022-07, Vol.15 (13), p.5309-5335
• Main Authors: Suter, Ivo, Grylls, Tom, Sützl, Birgit S, Owens, Sam O, Wilson, Chris E, van Reeuwijk, Maarten
• Format: Article
• Language: English
• Subjects: Air pollution; Air quality; Analysis; Atmospheric boundary layer; Atmospheric models; Boundary conditions; Boundary layers; Climate; Climate change; Computer simulation; Computer-generated environments; Dispersion; Emissions; Energy; Energy balance; Energy demand; Enthalpy; Environmental conditions; Force and energy; Heat; Heat flux; Heat storage; Heat transfer; Large eddy simulation; Large eddy simulations; Local climates; Local flow; Long wave radiation; Microclimate; Morphology; Oceanic eddies; Planetary boundary layer; Policy and planning; Pollutants; Radiation; Sensible heat; Short wave radiation; Simulation; Simulation models; Surface energy; Surface energy balance; Surface properties; Sustainable urban development; Temperature effects; Turbulence models; Urban air quality; Urban areas; Urban climates; Urban environments; Urban microclimates; Urban planning; Vegetation; Ventilation; Vortices; Wind tunnel testing; Wind tunnels
• ISSN: 1991-9603; 1991-959X; 1991-962X; 1991-9603; 1991-962X
• DOI: 10.5194/gmd-15-5309-2022

Urban environments are of increasing importance in climate and air quality research due to their central role in the population's health and well-being. Tools to model the local environmental conditions, urban morphology and interaction with the atmospheric boundary layer play an important role for sustainable urban planning and policy making. uDALES is a high-resolution, building-resolving, large-eddy simulation code for urban microclimate and air quality. uDALES solves a surface energy balance for each urban facet and models multi-reflection shortwave radiation, longwave radiation, heat storage and conductance, as well as turbulent latent and sensible heat fluxes. Vegetated surfaces and their effect on outdoor temperatures and energy demand can be studied. Furthermore, a scheme to simulate emissions and transport of passive and reactive gas species is present. The energy balance has been tested against idealised cases and the dispersion against wind tunnel experiments of the Dispersion of Air Pollution and its Penetration into the Local Environment (DAPPLE) field study, yielding satisfying results. uDALES can be used to study the effect of new buildings and other changes to the urban landscape on the local flow and microclimate and to gain fundamental insight into the effect of urban morphology on local climate, ventilation and dispersion. uDALES is available online under the GNU General Public License and remains under active maintenance and development.