圆柱绕流的二维数值模拟和尾迹分析

为指导机械设计中参数和布局的选择，研究固定在水流中的圆柱结构件的受力情况和流场分布．利用FLUENT中的三种湍流模型对雷诺数为3900的圆柱绕流进行二维数值模拟并进行对比，得到升力因数、阻力因数、分离角、斯特劳哈尔数和涡街尺寸等参数的模拟结果，与参考文献中的实验结果对比验证二维模拟的预测精度．RKE（Realizable k-ε）和雷诺应力模型（Reynolds Stress Model，RSM）均能在此雷诺数下得出接近实验结果的流场，RSM模型使用POWER LAW离散格式的结果优于QUICK格式．与三维模拟的对比表明二维模拟适合在设计初期的快速估算，能够快速得到合适精度的模拟结果．

2D numerical simulation and wake analysis on flow around circular cylinder

As to the parameter and layout selection of mechanical design, the force and flow field distribution are researched for a circular cylinder mounted in water flow. By three turbulence models in FLUENT, the 2D numerical simulation is performed on flow around circular cylinder of which the Reynolds number is 3 900 and the results are compared. The parameters such as lift factor, drag factor, separation angle, Strouhal number and vortex street size are obtained, which are compared with the experimental results of references to verify the predication accuracy of 2D simulation. The results from both Realizable k-ε （RKE） model and Reynolds Stress Model（RSM） model are close to the experimental results under the same Reynolds number. In RSM model, the results obtained by POWER LAW discretization scheme is better than that of QUICK ,scheme. Compared with 3D simulation, 2D simulation shows advantage on draft calculation for concept design stage, which can obtain the simulation results with appropriate accuracy.