Experimental Studies of Wind Flow Inside a Street Canyon Between High-Rise Buildings with Angle of Attack Modifications

Failures of smaller structures located in between high-rise buildings due to wind have been observed. Further research on urban wind is needed o prevent further incidents. This research aims to investigate the wind flow in a street canyon of a cluster of 4 simplified symmetrical high-rise buildings with the angle of attack of 0o, 30o, and 45o. The study uses Particle Image Velocimeter (PIV) and Low Speed Wind Tunnel for the experiment. The results show that the flow at all angles can be defined as interaction flow, identified by two corner streams at the front passage entrance corner that interacts and merge into a single wide passage jet. The angle of attack changes the pattern of the flow in the cross-area. Before entering the passage, wind-blocking reduces the wind speed up to 40%. After entering the front building passage, its amplification rises to 6.9% above its original value at the angle of 0°, at the angle 30°, and 45° after entering it did not increase to its original value; the highest amplification rate occurred at 0o. At the angle of 30° and 45°, an extremely low wind speed region occurs in the cross area, which did not happen at 0°. It can be concluded that more complex patterns of building clusters lead to more vortex and turbulence in the cross area, which leads to decreasing speed. A “clashing point” from two flows (left and right passage) in its cross-section also leads to a higher turbulence rate in the cross area.