不同间距串列双球壳屋盖风荷载干扰效应大涡模拟

Large Eddy Simulation of Wind Load Interference Effects on Tandem Double Hemispherical Domeswith Different Spacing

采用基于空间平均的大涡模拟方法,以串列双球壳屋盖为对象,研究了对不同中心间距下串列屋盖的风致干扰效应。首先,将球心距为160 m的双球壳屋盖大涡模拟结果与风洞试验进行对比,验证了数值模拟方法及参数的有效性;其次,对比分析球心间距分别为160 m和190 m时双球壳屋盖表面的风压分布特征,研究了不同中心间距对球壳屋盖表面平均和脉动风压分布的影响;最后,结合非定常绕流风场,研究了中心间距对串列双球壳屋盖风荷载的影响机理。结果表明:考虑的中心间距下,串列双球壳屋盖的平均和脉动风压系数的变化趋势类似;上游屋盖的遮挡效应减弱了下游屋盖迎风面的正压,但当间距比较小时,下游屋盖的阻塞作用会加剧上游屋盖的流动分离,使得顶部天窗的局部风吸力明显增加;随着间距的增大,上游屋盖背风面的分离涡由小尺度条带涡变化为大尺度弧形涡,使得屋盖顶部天窗、上游屋盖背风面和下游屋盖迎风面的风压脉动更为显著。

Based on the spatially-averaged large eddy simulation method,the wind interference effect of the tandem double hemispherical domes was numerically studied considering different center spacing.The effectiveness of the present numerical simulation method and parameter settings was firstly verified by comparison between results of large eddy simulation and the wind tunnel test on the tandem double hemispherical dome with center spacing of 160 m.Then the wind pressure distribution characteristics on the tandem double hemispherical domes surface with the center spacing of 160 m and 190 m were compared and analyzed to study the influence of the interference effect.In conjunction with the simulated unsteady flow field,the mechanism of the influence on wind loads with different center spacing was investigated.Similar tendency was observed for the distribution of the mean and fluctuating wind pressure coefficients of the tandem double spherical shell roof with different center spacing.The blocking effect of the upstream roof weakened the positive pressure on the windward surface of the downstream roof.However,the blocking effect of the downstream roof would intensify the flow separation of the upstream roof when the spacing was small,resulting in a significant increase in the local wind suction on the top skylight.As the spacing increased,the separated vortex on the leeward surface of the upstream roof could change from small-scale strip vortex to large-scale arc-shaped one,leading to more significant wind pressure fluctuations on the roof skylight,upstream leeward surface,and downstream windward surface.