As a result of the extensive utility of high-strength and light-weight materials in construction,high-rise buildings tend to be very vulnerable to the wind loads, and the wind-resistance design has gradually become the dominate factor in structural designs. To reduce the wind-induced drag force and improve the wind-resistance performance of a high-rise building, the active suction control is proposed to investigate the drag-reduction property via numerical simulation. Effects of the slot locations along the height, the suction heights and suction velocities on the drag-reduction property are analyzed. Moreover, the detailed flow field is presented to discuss the mechanism of the suction control. The results indicate that, as the suction height increases, coefficient of pressure reduction, coefficient of drag reduction and coefficient of along-wind base moment reduction will increase under the same suction velocity, and their efficiencies (efficiency of pressure coefficient reduction ηPR, efficiency of drag reduction ηDR and efficiency of along-wind base moment reduction ηMR) will decrease until 1.0. On the other hand, the ηPR (ηDR or ηMR) will increase along with the increment of suction height under the same flux coefficient, and only the ηMR will be greater than 1.0 at larger suction height. Based on the analysis above, formulae of the ηDR and ηMR versus the slot location, suction height and suction velocity are regressed to be referred for practical application of subsection suction on the highrise building. Lastly, comparison of the drag-reduction property of the subsection suction models and all-height suction model are performed based on the maximal drag-reduction efficiencies and the minimal power consumed,and the latter is superior to the formers. However, the subsection suction is still practical, as it can be used on upside of high-rise buildings to reduce the base moment or improve the local wind pressure characteristics.%为减小高层建筑的风致阻力,采用CFD方法研究了主动吸气控制下高层建筑模型的风载荷减阻性能,分析了竖向开孔位置、吸气孔高度和吸气速度等参数对减阻性能的影响,并详细展示流场,讨论吸气控制机理.结果表明:保持流量系数不变,增加吸气孔高度(或减小吸气速度)使得模型各表面的风压折减效率ηPR,阻力折减效率ηDR和基底弯矩折减效率ηMR增大,且只有ηMR在较大吸气孔高度时超过1.0.拟合了ηDR和ηMR关于吸气孔中心高度、吸气孔高度和吸气速度的经验公式,为分段吸气控制的应用提供参考.基于最大风压折减效率和最小吸气功率,比较了各分段吸气模型和全高吸气模型的减阻性能,发现全高吸气模型的减阻性能优于分段吸气模型.可在高层建筑中上部设置吸气装置来减小基底弯矩或改善其局部风压特性.
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