亚临界雷诺数下圆柱受迫振动的数值研究

Two dimensional numerical simulation of forced oscillating cylinder at sub-critical Reynolds numbers

在Navier-Stokes方程和k-ω湍流模型的基础上,利用流线迎风有限元方法结合ALE动网格技术对亚临界雷诺数下的圆柱受迫振动问题开展了数值模拟研究。本文的数值模型成功模拟了Re=5000条件下,圆柱发生受迫振动时尾迹区内的2S,2P和P+S尾流模式;对Re=10000情况下,无量纲振幅分别为0.3,0.4,0.5的圆柱受迫振动问题开展了数值模拟,分析了给定振幅条件下圆柱受力随振动频率的变化关系以及受迫振动的锁定区间。以上数值计算结果与Gopalkrishnan(1993)的实验结果基本符合。研究结果表明,二维数值模型能够基本正确地反映出圆柱发生受迫振动时的涡激振动特性以及有关的受力变化趋势,为今后进一步开展三维数值分析工作奠定了基础。

Based on the Navier-Stokes equations,κ-ω turbulent model, SUPG Finite Element method and Arbitrary Lagragian-Eulerian method, a numerical model is developed in this work to investigate the forced oscillation of circular cylinder in uniform flow. The 2S, 2P and P--S wake modes are simulated successfully in the wake region at Re= 5000. The lift and drag coefficients are in good agreement with the available numerical and experimental data. The variations of fluid forces with the oscillation frequencies of circular cylinder at different non-dimensional amplitudes of 0.3, 0.4 and 0.5 at Re=10000 are also examined. The lock-in region is obtained and agrees well with the experimental data. It shows that the present two-dimensional model is able to predict the characteristics of VIV, but the three-dimensional viscous numerical model is necessary for the accurate numerical simulation.