基于二维RANS模型计算扁平箱梁漩涡脱落的可行性分析

发布时间：2018-04-08 16:17

本文选题：桥梁工程　切入点：扁平箱梁　出处：《中国公路学报》2015年06期

【摘要】：为研究二维雷诺时均Navier-Stokes(RANS)模型在获取桥梁扁平箱梁漩涡脱落特性时的可行性,采用基于SSTk-ω湍流模型的二维RANS方程,对大带东桥主桥加劲梁进行了CFD计算(雷诺数Re=1.06×105),获得了加劲梁在不同迭代时间步长、不同网格划分上的气动力系数平均值和脉动值,以及漩涡脱落Strouhal(Sr)数,突出了计算时间步和网格无关检查的重要性。结果表明:相对于漩涡脱落周期T,采用较大的时间步长就能获得气动力系数平均值的近似估计,而要获得漩涡脱落Sr数的收敛估计之计算时间步长应小于T/260;采用二维RANS模型能获得此种箱梁平均气动力系数的近似估计,但得到的漩涡脱落Sr数与风洞试验结果有较大差别。
[Abstract]:In order to study the feasibility of the two-dimensional Reynolds averaged Navier-Stokescan-RANS model in obtaining the vortex shedding characteristics of the bridge flat box girder, the two-dimensional RANS equation based on the SSTk- 蠅 turbulence model is adopted.The CFD calculation of the stiffened beam of the main bridge of the large belt east bridge is carried out (Reynolds number Re=1.06 脳 105). The average and pulsating values of aerodynamic coefficients and the vortex shedding of the stiffened beam are obtained in different iteration time steps, different mesh division, and the number of vortex shedding.The importance of computing time step and grid independent checking is highlighted.The results show that relative to the period T of vortex shedding, the approximate estimation of the mean value of aerodynamic coefficient can be obtained by using a large time step.In order to obtain convergence estimation of vortex shedding Sr number, the calculating time step should be smaller than T / 260. The approximate estimation of the average aerodynamic coefficient of box girder can be obtained by using two-dimensional RANS model, but the calculated vortex shedding Sr number is quite different from the wind tunnel test results.
【作者单位】：湖南大学土木工程学院;
【基金】：国家自然科学基金项目(51278191) 国家重点基础研究发展计划(“九七三”计划)项目(2015CB057702)
【分类号】：U441.3

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