竖向肋条对高层建筑局部覆面风压的影响

Effects of vertical ribs on local cladding pressure of high-rise buildings

摘要:

为探究竖向肋条对高层建筑局部风压的影响,采用风洞试验方法研究不同肋条布置情况下高层建筑平均风压和脉动风压的分布特性,分析功率谱和POD模态的变化,探究竖向肋条布置后的风压非高斯性分布变化,最后给出不同工况极值风压系数。结果表明:肋条布置后迎风面的平均风压、脉动风压和极值风压均没有差异；而侧面肋条分界线上的前缘区域负压平均值、脉动值和极值风压有所增大,其余区域负压均减小；由POD可知对风场能量贡献最大为横风向气动力,肋条的布置使得一阶主坐标功率谱峰值降低,肋条分界线上的前缘区域位置的模态值增大较多；肋条布置后侧风面的非高斯性测点个数减少,背风面没有明显变化。其中半布和满布工况对局部风压特性造成的差异相差不大,说明中部的肋条对局部风压影响较小。

Abstract:

The influence of vertical ribs on the local cladding pressure of high-rise buildings was investigated. The distribution characteristics of mean wind pressure and fluctuating wind pressure of high-rise buildings with different rib configurations were studied via wind tunnel tests. The variation of power spectra and proper orthogonal decomposition (POD) mode was analyzed. The non-Gaussian characteristics of wind pressure caused by the arrangement of vertical ribs were discussed. Finally, the extreme wind pressure coefficients in different cases were presented. Results show that there were no distinctions between the mean wind pressure, fluctuating wind pressure, and extreme wind pressure on the windward side when ribs were installed. While at the leading edge above the rib boundary on the side face, the mean value, fluctuating value, and extreme value of negative pressure increased, and those in other regions decreased. According to POD, the crosswind aerodynamic force contributed most significantly to the energy of the wind field. The installment of ribs decreased the power spectrum peak of first-order principal coordinate and increased the modal value of the leading edge regions above the rib boundary. The number of taps with non-Gaussian distribution on the side face decreased after the installation of ribs, while there was no evident change on the leeward side. The discrepancies were minor in the local pressure characteristics between half-distributed and full-distributed cases, indicating that ribs in the middle have little influence on the local cladding pressure.