雷诺数对大跨屋盖结构表面风压的影响

摘要

为研究不同雷诺数对大跨度屋盖结构表面风压分布特性的影响，采用大涡模拟计算流体动力学方法，计算二维屋盖表面平均和脉动风压系数；系统分析雷诺数对屋盖表面风压分布、流动分离及再附着现象的影响。数值计算结果表明：随着屋盖表面特征雷诺数的变化，屋盖表面风压分布亦发生明显变化，特征雷诺数较低时屋盖表面风压较平稳，特征雷诺数升高时屋盖前部的风压系数大幅增大，但增幅逐渐降低，最终趋于稳定。结果验证了雷诺数效应在屋盖结构风荷载模拟中的重要影响。%Reynolds numbers have great effects on the pressure distribution of large⁃span roof structure. To explore these issues, Large Eddy Simulation ( LES) numerical method was adopted to calculate mean and fluctuation wind pressure distributions. The pressure values, flow separation and reattachment patterns were examined by corresponding experiment data. Results indicate that the pressure distribution changed dramatically with different Reynolds numbers. Pressure distribution keep srelatively stable in low Reynolds number flow field, while for high Reynolds number flow, pressure varies rapidly at the leading edge area of the roof and gradually decreases to a constant value. The simulation results prove that Reynolds numbers have critical effects on the pressure distribution of the large⁃span roof structures.