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为研究箱梁脉动风压的频域特征和空间相关性,采用大涡方法模拟了箱梁在0°风攻角和雷诺数为1.27×105下的绕流场,获得了主梁表面脉动压力分布和统计特征,开展了脉动压力时程的频域和空间相干性分析,解释了脉动压力的流动机理。研究结果表明:主梁尾迹的主脱落漩涡主导了主梁表面脉动压力,且涡脱存在频率带宽分布和展向不同步特征;主梁下表面脉动压力同相相关,但顶板脉动压力受分离再附流的干扰,上游风嘴及附近的脉动压力漂移了180°相位,导致上表面前、后风嘴上的脉动压力反相,且流动平均再附点后较大区域,脉动压力相干性小且相位杂乱。
In order to study the frequency-domain characteristics and spatial correlation of the pulsating wind pressure in the box girder, a large eddy simulation is used to simulate the flow around the box girder at a wind attack angle of 0 ° and a Reynolds number of 1.27 × 105, and the pulsating pressure Distribution and statistical characteristics, carried out the frequency-domain and spatial coherence analysis of the pulsating pressure time-history, and explained the flow mechanism of the pulsating pressure. The results show that the main shedding vortices dominate the fluctuating pressure on the surface of the main beam, and the frequency bandwidth distribution and unsynchronized characteristics of vortex shedding occur. The pulsating pressure on the lower surface of the main girder is correlated with each other. However, the pulsating pressure of the roof is separated and re-attached Flow disturbance, the upstream nozzle and the pulsation pressure near the drift of 180 ° phase, resulting in the front surface of the nozzle on the mouth after the pulsating pressure reversal, and the flow of re-attached after a larger area, the pulsating pressure coherence is small and Messy phase.