带附体圆柱的涡激振动特性研究

以带鳍状物附体二维圆柱为研究对象,采用动网格技术,通过FLUENT自定义函数接口进行流场与结构间的数据交换,对其涡激振动特性进行了数值研究.数值分析前,以裸圆柱为模型进行了计算并将结果与已有的实验数据进行了对比,验证了本文算法的有效性和准确性.数值计算中,分别对初始分支、超上端分支及下端分支条件下的带附体圆柱在不同来流攻角的涡激振动特性进行了研究.计算结果表明,对于初始分支与超上端分支,附体的存在能够减小圆柱的横向振动；下端分支在小来流攻角情况与初始分支类似,但在大来流攻角时附体的存在会增大圆柱的振动幅值.

Analysis of Vortex-induced Vibration of a Finned Cylinder

The characteristics of two-degree-freedom vortex induced vibration of a finned cylinder are investigated.The dynamic mesh is adopted to simulate the moving boundary,the user defined function（UDF）in FLUENT is used to exchange the data between fluid domain and solid domain.4th RungeKutta method is used to calculate the velocity and displacement of the cylinder in each time step.Experimental data are used to compare with the numerical simulations to verify the accuracy of the investigation by simulating the vortex induced vibration of a bare cylinder.Seven different velocity angles of three transverse amplitude branches are numerically simulated.The results show for initial branch and supper-upper branch,the transverse amplitude of the cylinder can be decreased by the fin in small velocity angles,and in large velocity angles the fin has little effect on the amplitude;for lower branch while the angle is greater than 40,the existence of the fin greatly increases the amplitude of the cylinder.This can give a consult of the design of VIV of cylinders.