The air quality in two-dimensional urban canyons with gable roof buildings: A numerical and laboratory investigation

In this work we compare two typical methods (numerical simulation and laboratory experiment) of modelling air flows at the urban scale to assess air quality in street canyons. We have investigated, both via numerical simulations and laboratory experiments, the effect of gable roofs, on the air quality in urban canyons with different aspect ratios. In particular, we have focused on the flow regimes, turbulence characteristics and air exchanges between the urban canyon and the outer flow. Results highlight how the choice of the roof shape can be meaningful for building design, planning strategies and regulatory purposes.