采用有限体积法对具有不同倒角半径方柱涡激振动开展了数值研究。方柱涡激振动系统简化为两自由度的质量-弹簧-阻尼模型,引入雷诺平均应力模型求解不可压缩粘性Navier-Stokes方程,结合SST k??湍流模型对低质量比弹性支撑的方柱涡激振动进行了模拟。研究发现:方柱涡激振动最大振幅曲线随着折合速度的增大先增大后减小,与圆柱涡激运动初始激励分支和下端分支相类似,但没有发现幅值跳跃现象。流向振幅最大值出现在20%倒角且折合速度5.0时,大小为0.28D,而横向振幅在30%倒角工况中折合速度为6.0时达到最大值0.47D。方柱涡激振动没有发生类似圆柱一样的频率锁定现象,但其振幅呈现明显的"差拍"规律,差拍区间随倒角半径大小而异,最后对不同倒角半径下方柱运动轨迹进行了讨论分析。
The finite volume method is applied in simulating vortex-induced vibration of a square column with different filleting radius, which can be simplified as a spring-mass-damping model. Reynolds-averaged Navier-Stokes solver combined with the SST (shear-stress transportation) k-a) turbulence model is applied to solving the vortex induced vibration. It is found that vibration amplitude of the square column first increases and then decreases with the increase of the reduced velocity, which is similar to the initial branch and lower branch of circular column's vortex-induced vibration, but the phenomenon of 'jump' is not observed on the amplitude curve. The maximum amplitude appears in stream-wise at reduced velocity of 5.0 when the chamfering radius is 20 percent, and the maximum value is 0.28D. However, the transverse maximum amplitude is 0.47D at the reduced velocity of 6.0 while the chamfering radius is 30 percent. Unlike the circular column's vortex-induced vibration, the phenomenon of lock-in doesn't happen, but the phenomenon of 'beat' is found on the time history curve. The beat interval varies with the chamfering radius. Finally, motion trajectories of the square column with different filleting radius are discussed.