Attenuation of the unsteady loading on a high-rise building at different angles of attack using pulsed jet forcing

With the severity and frequency of significant weather events increasing, it is critical to investigate methods for alleviating unsteady wind loading for high-rise buildings. This study numerically investigates the 3D flow structures around a canonical high-rise building immersed in an atmospheric boundary layer at different oncoming wind angles, using large eddy simulations. The effect of the downwash flow near the top of the building on the spanwise vortex shedding is analysed. Exploiting this idea, a synthetic jet located on the top surface is used as an open loop active actuation to suppress the building's side-force fluctuations when exposed to oncoming wind variations via enhancing the downwash flow. Actuation across different frequencies is investigated numerically, and its effect on the time-averaged flow fields and the unsteady flow structures for cases with different oncoming wind angles explored. To the authors' knowledge, this work presents a first attempt at employing active actuation to control the three-dimensional wake of a high-rise building exposed to differing oncoming wind directions