不同雷诺数下二维椭圆柱绕流的数值模拟研究  

Numerical simulation of flow around a two-dimensional elliptical cylinder with different Reynolds numbers

作　　者：刘二朋 陈威[1] 林永水[1] 王思莹[1] 李营 Liu Erpeng;Chen Wei;Lin Yongshui;Wang Siying;Li Ying(Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics,Wuhan University of Technology,430063,Wuhan,China;Institute of Advanced Structure Technology,Beijing Institute of Technology,100081,Beijing,China)

机构地区：[1]武汉理工大学新材料力学理论与应用湖北省重点实验室,武汉430063 [2]北京理工大学先进结构技术研究院,北京100081

出　　处：《应用力学学报》2021年第5期2025-2031,共7页Chinese Journal of Applied Mechanics

基　　金：武汉理工大学新教师基金(40120268);博士科研启动金(3120619082)。

摘　　要：利用计算流体力学软件Fluent对不同雷诺数(Re=100,3900,3.5×10^(6))下二维椭圆柱绕流进行了数值模拟研究,分析了不同轴长比(2b/2a=cosθ,θ=0°,15°,30°,45°,60°)下椭圆柱绕流的特性。通过对比尾部涡流情况、升力系数CL、阻力系数CD以及斯特劳哈尔数St初步发现:由于椭圆形截面偏流线型的特点,在三种雷诺数下随着θ的增大椭圆柱绕流尾涡强度减小,流场的变化使圆柱表面的压力系数减小,最终导致圆柱的升力系数幅值与阻力系数均值减小。而斯特劳哈尔数St在三种雷诺数下的变化不同,随着θ的增大,层流雷诺数(Re=100)下St值减小;亚临界雷诺数(Re=3900)下St值在45°处轻微上扬,在60°处明显减小;超临界雷诺数(Re=3.5×10^(6))下St值增大。The computational fluid dynamics software Fluent was used to numerically study the flow around a two-dimensional elliptical cylinder under different Reynolds numbers(Re=100,3900,3.5×10^(6)).The different axial length ratios(2 b/2 a=cosθ,θ=0°,15°,30°,45°,60°)characteristics of flow around an elliptical cylinder.Through comparison of the eddy current at the tail,the lift coefficient C_(L),the drag coefficient C_(D),and the Strouhal number St,it is found that due to the characteristics of the elliptical cross-section deflection line,the elliptic cylinder flows around with the increase ofθunder three types of Reynolds numbers.The strength of the wake vortex is reduced,and the change of the flow field reduces the pressure coefficient of the cylindrical surface,which ultimately leads to a decrease in the average value of the cylindrical lift coefficient amplitude and the drag coefficient.The Strouhal number St changes differently under the three Reynolds numbers.With the increase ofθ,the St value decreases in the laminar flow Reynolds number(Re=100);in the subcritical Reynolds number(Re=3900),the St value rises slightly at 45°and decreases significantly at 60°;the St value increases at the Reynolds number(Re=3.5×10^(6))of the supercritical.

关 键 词：椭圆柱绕流 数值模拟 漩涡脱落 阻力系数 轴长比 

分 类 号：TV131[水利工程—水力学及河流动力学]