高雷诺数下质量比对圆柱涡致振动影响分析

Numerical analysis of mass ratio effects on vortex-induced vibration for a single-degree-of-freedom circle cylinder at high Reynolds numbers

涡致振动分析可为柔性结构抗风研究与工程应用提供重要理论依据。采用基于非平稳雷诺均值Navier-Stokes方程(Unsteady Reynolds-Averaged Navier-Stokes equations,URANS)的数值方法模拟了高雷诺数、高质量比条件下单向自由度圆柱的涡激振动。在改进的剪切应力输运k-ω(Shear Stress Transport,SST k-ω)模型基础上,运用动网格技术实现流固耦合,并结合Newmark-β方法求解结构运动方程。在雷诺数为1.39×104~1.04×105、折算速度为2~12的条件下,模拟分析了圆柱在不同折算速度时的涡激振动响应,得到了不同质量比时圆柱涡激振动的振幅比、振动频率比、升力系数等的变化特点,讨论了圆柱振动响应和旋涡脱落特性,分析总结了高雷诺数下不同质量比的圆柱涡激振动特性规律。结果表明:数值结果与已有试验的吻合程度较好;雷诺数和质量比对圆柱的涡激振动影响效果明显,对进一步分析圆柱涡致振动具有参考意义。

Vortex-induced vibration analysis provides a crucial theoretical basis for wind resistance research and engineering application for the flexural structures.Vortex-induced vibration is one of the main subjects in structural wind engineering field.The vortex-induced vibration of a circular cylinder system at high Reynolds numbers and high mass ratios is numerically simulated based on unsteady Reynolds-averaged Navier-Stokes equations(URANS)methods.The improved SST k-ωturbulence model is employed,and fluid-solid interaction is achieved by dynamic meshing technique.The structure motion equation is solved using the Newmark-βmethod.The characteristics of transverse oscillation of the cylinder are analyzed.Simulations are conducted over a Reynolds number range from 1.39×104 to 1.04×105,and the corresponding reduced velocities ranging from 2 and 12.This paper calculates the VIV responses of the cylinder under different reduced velocities.The vortex-induced vibrations of the circular cylinder with different mass ratios under different reduced velocities are calculated.The variations of oscillation amplitude ratio,vibration frequency ratio,and lifting coefficient with different mass ratio and different high Reynolds number are discussed.The characters of vibration amplitude responses and vortex shedding patterns under the above conditions are also analyzed.The results indicate that the numerical results align well with existing experimental data;the Reynolds number and mass ratio have significant effects on the vortex-induced vibration of the cylinder,providing valuable insights for further analysis of vortex-induced vibrations in cylinders.