屋盖开孔建筑的内压风洞试验研究

Wind tunnel tests on internal pressures of buildings with a roof opening

对不同开孔位置、开孔率和内部容积的17个屋盖开孔建筑进行了缩尺刚性模型测压试验,分析内外风压的空间分布规律和相关性,采用稳态方法和单开孔内压传递方程分别对平均和脉动内压进行理论估计,拟合了峰值内外压系数比的无量纲设计公式。结果表明:屋盖开孔建筑的内部风压系数相关性和相干性较好,可采用统一的值来描述内压;内外风压系数以正相关为主,相关性大于立墙开孔工况;平均内压设计值可取为0.8倍开孔处外部平均风压,可采用单开孔内压传递方程估计垂直风向的脉动内压,误差小于15%。拟合的脉动内外压系数比和峰值内外压系数比设计公式,可应用于屋盖中心开孔建筑,改进了GINGER方法的精度。

The effects of seventeen roof opening configurations on the internal pressures in a typical TTU building were examined by wind tunnel tests with the volume-scaled method. The configurations examined are of different opening locations and sizes,as well as the different volumes of internal spaces. The spatial distributions of the internal and external pressures and the correlations between them were specially studied. Theoretical methods for estimating the mean and rootmean-square of internal pressures were introduced,and a dimensionless formula for peak internal pressure coefficients ratio was fitted. The results show that the internal pressures in roof opening buildings are highly correlative and coherent,so the internal pressure coefficients in roof opening building can be described by using a unified value. The correlation coefficients between external and internal pressure coefficients are positive,and larger than those in wall opening cases.The mean external pressure coefficients around the opening multiplied by 0. 8 can be used to estimate the mean internal pressure coefficients. For single dominant opening buildings,the Helmholtz equation can be used to simulate the fluctuating internal pressure,and the estimation error is below 15% for the wind in vertical orientation. The empirical formulas about the ratio between fluctuating internal pressure and external pressure,and the ratio between peak internal pressure and external pressure were fitted with the non-dimension opening parameters,which are more effective than other methods,such as GINGER method and HOLMES method.