阻塞效应对高层建筑风洞试验的影响分析

Investigation on Blocking Effect of High-Rise Building in Wind Tunnel Experiment

风工程界对单体建筑风洞试验阻塞效应进行了大量研究并取得初步成果,有关群体建筑风洞试验阻塞效应的研究却鲜有报道。基于此,本文对具有较多周边建筑的某实际高层建筑进行了两种缩尺比的刚性模型测压试验。结果发现阻塞效应的不同使两组模型的风压数据出现显著差异。分析表明:对于具有较多周边建筑的风洞试验,较大阻塞比导致的阻塞效应可能引起试验数据严重失真,阻塞效应对模型侧面风压的影响较迎风面、背风面更为显著;现有的阻塞效应修正方法不具有普遍适用性,阻塞比这一整体性指标无法描述模型不同部位的阻塞效应。

Investigation on blocking effect of single building with rectangular cross-section was carried out extensively and achieved initial success.However,it is rarely reported about the investigation on the blocking effect of group of buildings in tunnel experiment.Therefore,pressure measurement was carried out for a practical rigid model with many surrounding buildings based on two different scale ratios.It was found that the pressure data of two models are significantly different due to the blocking effect.Analysis results show that,for wind tunnel model experiment with more surrounding buildings,blocking effect may results in serious data distortion.The blocking effect on side air pressure is more serious than that on windward side and leeward side air pressure.Existing correction method of blocking effect does not have general applicability.Moreover,the blocking ratio,as a global index,cannot describe the blocking effect at different positions on a mode.