Wind tunnel experiment on turbulent flow field around 2D street canyon with eaves

In this study, the influence of the complexity of shape of roughness on turbulent flow fields in a 2D street canyon was investigated using a wind tunnel experiment (WTE). Time-resolved particle image velocimetry (TR-PIV) was employed to investigate temporally averaged flow fields, the spatial distributions of turbulent statistics, canyon ventilation rates, and the flow exchange mechanism between the regions above and inside a canyon. The measurements revealed that the temporally averaged flow fields and the spatial distributions of turbulent statistics are drastically changed by the complexity of roughness, especially when the canyon aspect ratio is small. Moreover, the ventilation rate is reduced by the eaves attached to roofs. However, the decreasing rate of the ventilation strongly depends on the canyon aspect ratio.