Twisted-wind effect on the aerodynamic force acting on varying side-ratios tall buildings: Fid-Bau Portal

Twisted-wind effect on the aerodynamic force acting on varying side-ratios tall buildings

Yuan, Yangjin / Yan, Bowen / Zhou, Xuhong / Yang, Qingshan / Wei, Min / He, Yuncheng / Zhou, Xu / Li, Xiao

Abstract The influence of side ratio on the aerodynamic performance of tall buildings is investigated by pressure measurement experiments in a mimicked twisted wind field (TWF) with the maximum twisted angle of 30° and its corresponding conventional wind field (CWF). The global wind loads and distribution of local wind forces on the buildings with different side ratios are analyzed in TWF and compared with those in CWF. Additionally, the effect of side ratio on the spatial correlations of aerodynamic forces in temporal and frequency domains and their spectral features are discussed in the two fields. The results show that the aerodynamic forces are largely affected by the side ratio of tall buildings in TWF. The correlation coefficients of local lateral wind force in the TWF are decreased by 0.1–0.4 compared with those in CWF. The trajectory envelopes of the base moment components in lateral and torsional directions are positively inclined, and the building with B/D = 2 takes the maximum correlation coefficient. The spectral peak of local torsional forces is diminished with the increasing side ratio in TWF and CWF, and the peak frequency in TWF deviates from that in CWF even though the building is under the equivalent wind direction at some specific elevations. This study aims to provide some useful insights into the twisted wind effect on tall buildings with varying side ratios.

Highlights • The effect of side ratio on the aerodynamic performance of the tall building under TWF are studied based on wind tunnel tests. • The spatial correlations of local wind forces are reduced by 0.1–0.4 due to the twisted wind direction along the elevation. • The fluctuation of torsional force at the maximum twisted angle range is due to vortex shedding for the building with B/D> 3. • The coherences of lateral wind forces and torsional moment are decreased due to the reduced vortex shedding in TWF.