新型斜拉桥与摩天轮复合结构流场数值模拟与风洞试验研究

STUDY OF FLOW FIELD NUMERICAL SIMULATION AND WIND TUNNEL TEST ON HYBRID STRUCTURE OF NEW CABLE-STAYED BRIDGE WITH GIANT WHEEL

为研究天津慈海桥的压强分布系数,建立了新型斜拉桥与摩天轮复合结构有限元模型,采用了RANS的RNGk-ε模型作为慈海桥进行数值分析的湍流模型,采用非平衡壁面函数模拟壁面附近复杂的流动现象。运用数值风洞法对斜拉桥部分周围流场进行数值模拟,得到斜拉桥周围流场的速度分布和斜拉桥表面的压强系数。通过风洞试验进行测量,介绍了风洞试验的风洞和试验模型,得出了32个测点不同方向的压强系数。把其中具有代表性的测点数值风洞理论值与风洞试验结果进行比较分析,结果对比说明:理论与试验数据一致,所得到的压强分布系数可以用于工程实际。同时证明该文所采用的数值模拟方法来预测斜拉桥表面的平均压强分布情况可以推广应用。

Finite element model of hybrid structure of new cable-stayed bridge with giant wheel was established in order to study the pressure coefficient distribution of Tianjin CiHai Bridge. The RNG k-ε of RANS model was adopted as the turbulent model of CiHai Bridge and the non-equilibrium wall function was used to analog the complex flow phenomenon around the wall. Through the numerical analysis of the flow phenomenon around the cable-stayed bridge by means of numerical wind tunnel, the speed distribution of the flow field around the cable-stayed bridge and the wind-pressure coefficient distribution in the surface of the cable-stayed bridge were obtained. With tunnel test, the pressure coefficients from different directions of 32 measuring points were acquired. The theoretical value of numerical wind tunnel and the wind tunnel test value were compared, and the result showed that they are uniform and the pressure coefficient distribution can be used for the project. Thus to predict the average pressure distribution of the surface of cable-stayed bridges, the numerical simulation method adopted in this paper could be generalized.