摘 要:本文为了研究在突变气流作用下结构的空气动力特性,介绍了利用主动控制风洞模拟突变气流的试验研究。首先通过该风洞模拟出了雷暴冲击风阵风剖面;然后,采用“阶跃流法” 模拟了风速突变的时程;最后将高层结构模型置于该突变气流中,观测在特殊气流中结构表面风压以及结构空气动力学参数的变化特征。试验结果表明,利用主动控制风洞模拟出的雷暴冲击风阵风剖面同理论的相似性达到90%以上,突变气流会使高层结构整体产生较大的非定常升力,并且在结构表面产生较大的非定常风压。
Abstract: In order to study the aerodynamic characteristics of the structure undergoing sudden change flow, this paper introduced the test on the simulation of sudden change flow by active control wind tunnel. Firstly, a gust velocity profile of Downburst was simulated by the wind tunnel. Subsequently, time history of wind speed changes was simulated by step flow method. Finally, high-rise structure models were prepared in the sudden change flow, and the variation characteristics of wind pressure on surface and aerodynamic parameters in the flow were observed and studied in this paper. The results showed that the identities between the gust velocity profile simulated by the wind tunnel and the theory formula were above ninety percent, and sudden change flow could generate a high unsteady lift on the whole high-rise structure and a big unsteady wind pressure on the surface of structure meanwhile.