积分尺度对矩形迎风面脉动风压特性的影响

为了研究来流紊流积分尺度对矩形断面高层建筑迎风面脉动风压及其分布特性的影响，选取2∶1和1∶2矩形为对象，通过风洞测压试验，对不同积分尺度紊流场中矩形迎风面的平均风压系数及脉动风压均方根系数、脉动风压相关函数和相干函数、脉动风压功率谱进行了对比分析. 研究结果表明:对于矩形同一高度处，脉动风压功率谱在低频区始终受准定常效应控制，而在高频区脉动风压功率谱随积分尺度的增大而增大；风压的相关性高于风的相关性，风压的相关函数与相干函数也随积分尺度的增大而增大，但相关宽度随积分尺度的增大而减小；脉动风压均方根系数随积分尺度的增大而增大；对于同一流场中矩形不同测点处，离驻点越远，风压相关函数和相干函数越小，脉动风压均方根系数越大；来流紊流积分尺度对平均风压系数的影响较小. 

Effect of Turbulence Integral Scale on Fluctuating Wind Pressure and Its Distribution Characteristics on Rectangular Upwind Surface

In order to study the influence of turbulence integral scale on the fluctuating wind pressure and its distribution characteristics on the rectangular windward surface of a high-rise building, rectangular models with 2∶1 and 1∶2 width-depth ratios were put in a wind tunnel to obtain statistical features of wind pressure in turbulent flow fields with different integral scales for comparative analysis, including the mean wind pressure coefficient, root mean square coefficient, correlation coefficient and coherence function, and power spectrum of fluctuating wind pressure. Results are as follows: At the same height of the rectangular model in different turbulence flow fields, the wind pressure power spectrum is dominated by a quasi-steady effect in low-frequency regions, but it increases as the integral scale increases in high-frequency regions. The correlation and coherence of wind pressure increases with the integral scale increasing, and wind pressure is always more correlated than the turbulence flow. However, as the integral scale increases, the correlation width of wind pressure decreases, and the root mean square coefficient of fluctuating wind pressure increases. On the other hand, at different heights of the rectangular model in the same turbulence flow field, the farther away from the stagnation point, the smaller the wind pressure correlation function and coherence function, and the larger the root mean square coefficient of fluctuating wind pressure. In addition, the mean wind pressure coefficient is rarely affected by turbulence integral scale.