中文摘要：

采用FLUENT中8个湍流模型以及曲率修正后的模型对U型弯管中的二维流动进行了模拟,详细对比了两个雷诺数10^5和10^6下速度、湍动能、湍流剪切应力、摩擦系数和静压力系数的实验和模拟结果。研究发现,当Re=10^5,Realizable k-ε模型、Spalart-Allmaras模型、RNG k-ε模型能准确模拟出流动分离的位置;当Re=10^6,所有模型预测到的分离位置都滞后。曲率修正对SKE以外的湍流模型预测性能基本上没有改善;SKE模型对曲率修正的影响最为敏感,对速度、湍动能、内壁面处的摩擦系数的模拟结果都有一定的改善。

英文摘要：

The flow in 2D of the u-bend is simulated,with eight common turbulence models and curvature correction model respectively.By comparing the simulation and experimental results of velocity,turbulence kinetic energy,turbulent shear stress,friction coefficient and static pressure coefficient under two kinds of Reynolds number 10~5 and 10~6,it is find that the Realizable κ-ε model,Spalart-Allmaras model and RNG κ-ε model have a good simulation results about the position of the flow separation when the Reynolds number is 10~5.Besides,the separation positions predicted by all models are lagging behind.The models with curvature correction are not better than before expect SKE.The model of SKE is more sensitive to the influence of curvature,and there is a greater improvement on simulation about velocity and turbulence kinetic energy.