| 摘要: |
| 为了研究不同倒角半径对方柱绕流特性的影响, 采用有限体积法, 模拟了雷诺数Re为22 500、倒角半径为0.1D(D为方柱边长的长度)、0.2D和0.3D时方柱的绕流过程。方柱近壁面采用增强壁面函数, 模型采用SST k–ω湍流模型。根据模拟结果给出了不同倒角半径下方柱的流场涡量图以及阻力系数Cd和升力系数Cl; 利用快速傅里叶变换法得到斯托罗哈数St。结果表明, 倒角半径的增加改变了方柱的分离点, 使得尾流区长度增加, 旋涡尺度减小;Cd和Cl的振动幅值呈现先减小后增大的趋势, 倒角半径为0.1D和0.2D时方柱受力较小, 不存在倒角时方柱受力较大, 倒角半径为0.3D时方柱受力最大;随着倒角半径的增加, 柱体截面形式越接近圆形, 斯托罗哈数逐渐增大, 漩涡脱落频率更快。 |
| 关键词: 方柱绕流 倒角半径 升力、阻力系数 漩涡脱落形态 斯托罗哈数 |
| DOI：10.11759/hykx20161120001 |
| 分类号: |
| 基金项目:山东省自然科学基金(ZR2017BEE047); 鲁东大学科研基金(LB2016010) |
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| Hydrodynamic characteristics and numerical simulation of flow around square cylinders at different filleting radii |
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DU Ming-qian,MAO Hai-ying,LI Yu-jia
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| Abstract: |
| To study the effect of different filleting radii on the flow characteristics around a square cylinder, in this study, we used Fluent software and the finite volume method to simulated a Reynolds number of 22 500, and applied filleting radii of 0.1 D, 0.2 D, and 0.3 D in a square cylinder flow process. We used an enhanced wall function for the wall near the square cylinder and the SST k–ω in our turbulence model. Based on the simulation results, we obtained the flow-field vorticity map, drag coefficient, and lift coefficient of a square cylinder with different filleting radii. We obtained the vortex shedding frequency by the fast Fourier transform method. The results show that the chamfer radius changed with an increasing separation column, with the wake length increasing and the vortex scale decreasing. We found the drag coefficient and lift coefficient amplitude to first decrease and then increase, with a square column stress radius for 0.1 D and smaller 0.2 D, and a unilateral column with a larger chamfer radius of 0.3 D. With an increase in the fillet radius, the column section is connected with a circular form, the Strouhal number increases, and the vortex shedding frequency is faster. |
| Key words: flow around square cylinder filleting radius lift and drag coefficient vortex shedding pattern Strouhal |
