大跨径悬索桥施工猫道气动力系数数值分析

Numerical Analysis of Aerodynamic Coefficients for Catwalk Considering Reynolds Number Effect on Long-span Suspension Bridge During the Construction

为了探讨用数值方法研究大跨径悬索桥猫道的气动力系数,并且考虑雷诺数效应的影响,以某大跨径悬索桥为背景,分别利用计算流体力学软件Fluent中的标准k-ε模型、RNG k-ε模型和SST模型,且采用一定的猫道透风率进行二维数值模拟,对猫道的气动力系数在不同风速、不同攻角和不同雷诺数情况下进行CFD识别,并与相应风洞试验的结果进行对比分析.结果表明:雷诺数的变化对阻力系数影响较小,但对升力系数影响较大,因此在进行猫道的数值模拟时,选择合适的雷诺数很有必要;SST湍流模型是猫道断面CFD识别中较合理的模型;模拟的猫道透风率是可行的.

Based on the long-span suspension bridge,and by means of the computational fluid dynamics software fluent,three different turbulence models such as the standard k-ε model,RNG k-ε model and SST model,have been used to recognize the aerodynamic coefficients of catwalk in the condition of different wind speeds,wind attack angles and Reynolds number with a ventilate rate of catwalk. The results of CFD identification are compared with the corresponding results of wind tunnel tests. Comparing the results of numerical simulation with those of wind tunnel test,it is proved that the variation of the drag coefficients is smaller with the different Reynolds number,but that of the lift coefficients is bigger. So the appropriate Reynolds number is very necessary for the catwalk numerical simulation. The results show that the SST model for CFD method of the catwalk section is reasonable model,and the ventilate rate of simulation for catwalk is feasible.