Physical mechanisms behind bimodal distribution of wind pressure between two square cylinders

Results from our previous study via pressure model wind tunnel tests demonstrated the existence of bimodal probability distribution (BPD) of wind pressure on the windward facade of an inter-fered high-rise building, and corresponding time series of wind pressure consisting of both negative (i.e., suction) and positive components. The above phenomena, which have been rarely reported, are expected to provide further insights to better understand the non-Gaussian features of wind pressure as well as the wind resistance of cladding structures for high-rise buildings. Although a preliminary explanation has been stated in the preceding work, the detailed mech-anism behind the aforementioned phenomenon remains to be revealed. To this end, this study aims to explore how the BPD phenomenon is generated through wind tunnel tests via particle image velocimetry (PIV) equipment. Results show that the shedding vortices on both sides of the principal building alternately impacted the interference building surface with the background flow, causing a distinct BPD of wind pressure at the measurement points.