高层建筑顶部桅杆的气动力特性研究OA

To analyze the aerodynamic force characteristics of masts on top of high-rise buildings,wind tunnel test models were fabricated for three typical masts,including constant cross-section,variable cross-section,and those with attached auxiliary components.The force measurement test with a rigid model was conducted to investigate differences in aerodynamic force coefficients and power spectra among three structural mast con-figurations,while also examining the influence of turbulence.The results indicate that both aerodynamic forces and vortex-induced force peaks are significantly reduced for variable-section masts compared with constant-section masts.Adding auxiliary structures slightly increases the aerodynamic forces of masts,but fur-ther weakens vortex-induced force energy.The turbulence significantly increases the aerodynamic forces of masts but reduces the peak of vortex-induced force and broadens its bandwidth.Aerodynamic forces on masts are generally lower when airflow strikes building facades directly compared with oblique impacts.Further-more,the separation flow generated by headwinds against the building facade significantly suppresses regular vortex shedding from the main structure at the mast base.Changes in wind direction markedly affect the vortex shedding frequency of uniform flow around constant-section masts,but have a negligible impact on variable-section masts.