倒梯形桁架桥断面气动参数研究

采用计算流体力学(CFD)和风洞试验相结合的方法,对某倒梯形桁架主梁断面二维等效模型和气动导纳函数进行研究。首先依据外轮廓和实面积比不变的原则,建立斜腹杆位置不同的二维模型,识别其静力三分力系数并与风洞试验结果对比,得到二维等效模型。随后基于二维SST k-ω湍流模型和2D LES模拟,对二维等效模型分别进行气动导纳数值识别,识别结果与风洞试验对比研究。结果表明:无论是基于RANS的SST湍流模型还是2D LES模拟,二维等效模型气动导纳识别结果均与Sears函数较为接近,而SST k-ω模型气动仿真结果与风洞试验吻合良好;采用文章所用模型简化和数值识别方法,可对桁梁的气动参数进行有效识别。

Study on Aerodynamic Parameters of Inverted Trapezoid Section of Truss Bridge

The two-dimensional equivalent model and the aerodynamic admittance of inverted trapezoid section of truss bridge are investigated by using computational fluid dynamics(CFD) methods and wind tunnel tests.Based on the principle of non-changing ratio between outer contour and real area,twodimensional models with different positions of diagonal web member are established,and their static coefficients are identified and compared with the wind tunnel test results to create the two-dimensional equivalent model.Then,based on two-dimensional SST k-ω turbulence model and 2 D LES simulation,the aerodynamic admittance of the two-dimensional equivalent model is identified and compared with the wind tunnel test.The results show that the two-dimensional equivalent model is close to the Sears function under both the SST turbulence model and the 2 D LES simulation,while the result of SST k-ω model is in good agreement with the wind tunnel test.By using the model simplification and numerical recognition method,the aerodynamic parameters of truss girder can be effectively identified.