方形高层建筑风压脉动非高斯特性分析

Analysis on Non-Gaussian Features of Fluctuating Wind Pressure on Square Tall Buildings

摘要:

通过风洞刚性模型动态测压试验，对单体方形高层建筑脉动风压非高斯特性进行了研究。首先依据测点偏度峰度及其概率密度函数图给出了高层建筑风压脉动非高斯特性的描述方式，然后分析了高层方形建筑脉动风压非高斯特性，最后给出了不同风向角下的非高斯区域。结果表明，风向角对结构非高斯特性的影响较大，对于直接受来流风作用的立面，其会同时出现正偏和负偏，而峰度值也相对较小，其主要以高斯区域为主，而受分离流和尾流综合作用的立面，该面均为负偏且峰度值相对较大，其主要以非高斯区域为主，当出现流体再附时，相应区域的负偏值会增大而峰度值则减小，导致非高斯区域过渡到高斯区域。

Abstract:

The non-Gaussian features of fluctuating wind pressures on square tall building are studied by using multi-channel measurement wind tunnel tests. The skewness, kurtosis and probability density function of fluctuating wind pressures are employed to obtain a description and measurement of the non-Gaussian features of the tall building firstly, then the non-Gaussian features of fluctuating wind pressures are analyzed, finally the regions with non-Gaussian feature under different wind angles are given. The results show that wind angle is important for the non-Gaussian features of the building. For the faces which wind directly impinged on, the positive and negative skewness appears simultaneously and the kurtosis is relatively small, so the Gaussian regions are major. However, for those associated with separated and wake flows, the negative skewness covers the whole face and the kurtosis is relatively large, so the non-Gaussian regions are major. As the reattachment happens, the negative skewness will increase and the kurtosis will decrease in the reattachment zones, as a result, non-Gaussian zones transition to Gaussian zones.