山区桥梁桥址风环境数值风洞研究

Numerical Wind Tunnel Research of Wind Environment at Sites of Bridges in Mountainous Region

为确保山区桥梁的抗风稳定性和安全性,根据计算流体动力学(CFD)基本原理,采用基于RNG、k-ε方程湍流模型的数值研究方法,利用计算流体力学软件FLUENT6.0对坝陵河特大桥桥址风环境进行了数值模拟,研究了桥位风场的特征状况。通过引入风速放大系数这一表征考察点与边界入口风速关系的无量纲参数得到16个不同来流风向下考察点的风速分布情况,并将桥位水平方向(横桥向和顺桥向)平均风速计算值与试验结果进行比较分析。结果表明:当来流风与桥位正交时,风速放大效应最明显;CFD计算结果与风洞试验结果存在一定的偏差,但在整体趋势上与试验结果吻合较好。

To ensure the wind resistant stability and safety of bridges in mountainous region,the numerical simulation for wind environment at the site of Baling River Bridge was made and the features of wind fields there were investigated,using the numerical research method of turbulence model based on the RNG κ-ε equation and the computational fluid dynamics（CFD） software FLUENT6.0.in accordance with the fundamental principle of the CFD.Through introduction of the non-dimensional parameters of the relation between the characterization observation points of the wind speed magnifying coefficient and the wind speed of the boundary entrance,the wind speed distribution of 16 different observation points under different inlet wind directions was obtained and the calculation values and testing values of the average wind speed in the horizontal direction（along and across the bridge） of the site of the bridge were compared and analyzed.The results indicate that when the inlet wind is normal to the site,the magnifying effect of the wind speed is the most distinctive.The calculations of the CFD has certain difference with those of the wind tunnel tests,but in general,the calculations tend to be is good agreement with the tests.