大比例TTU模型表面风压分布试验研究

采用1∶3大比例模型，通过风洞试验研究了美国德州理工大学（Texas Tech University, TTU）建筑模型表面平均、脉动、峰值风压系数的分布规律，并与实测数据和小比例模型试验数据进行了对比，分析了影响试验结果的部分因素。结果表明：TTU建筑模型典型位置的风压系数试验数据与实测值在整体规律性变化上一致，但试验低估了屋檐、屋角在风向角165°~240°范围内的脉动、峰值风压系数；越靠近屋角流动分离区域测点的风压系数绝对值也越大，最靠近建筑屋面角点的测点峰值风压系数达-16.7；大比例模型屋角、屋檐等区域试验结果更接近于实测值，排除了测点测压管直径不匹配的影响后，考虑到试验中湍流度模拟与实际的差异，大比例模型模拟效果更优；试验样本长度影响峰值风压系数的计算，在屋角区域，长样本峰值风压系数值均相对较大；而离屋角较远时，长样本的峰值风压系数则可能相对较小。

Experimental research on surface wind pressure distributionon large scale TTU model

Wind tunnel tests were conducted to study the mean, fluctuating and peak surface pressure coefficients distribution on 1∶3 large scale TTU standard model. The results were compared with those of field measurement and other wind tunnel tests with smaller scale model. Some effect factors on results were analyzed. The results show that, the overall change pattern of pressure coefficients on the typical positions on TTU model show good agreement with that of field measurement, while the test results underestimate fluctuating and peak coefficients in roof corners and eaves under azimuth 165°~240°. The closer to the roof corner flow separation district, the larger the absolute value of coefficient is. The peak coefficient is -16.7 at the point which is closest to the building’s corner. Test results at roof corners and eaves are closer to those of field measurement. Excluding the effect of non matching problem of model’s tube diameter, while considering the difference of turbulence intensity between test and field measurement, there is still certain advantage be use of large scale model in the wind tunnel test research. The wind pressure sampling length will affect the peak pressure coefficient calculation: at the roof corner district, longer sampling length will bring the larger peak coefficient, while at the district away from the corner, longer sampling length may bring the smaller peak coefficient.